BA-01X manual ver1_9 - NPI Electronic Instruments
Contents
1. start stop 12000 time ms Figure 2 buzz function of the BA 01X version 1 9 page 10 BA 01X User Manual 16 OFFSET potentiometer Control to set the output of the electrode preamplifier to zero ten turn potentiometer symmetrical 1 e 0 mV 5 on the dial range 200 mV see chapter 7 2 Control for compensation of the input capacitance ten turn potentiometer clockwise range 0 30 pF see chapter 7 3 Caution This circuit is based on a positive feedback circuit Overcompensation leads to oscillations which may damage the cell Important The capacity compensation for the electrode does NOT work if the oscillation shut off circuit 1s activated This may lead to an incorrect reading of the electrode resistance see also 31 especially when electrodes with high resistances are used 18 HEADSTAGE connector The HEADSTAGE is connected via a flexible cable and an 8 pole connector to the mainframe see also chapter 3 3 Caution Please always adhere to the appropriate safety regulations see chapter 1 Please turn power off when connecting or disconnecting the headstage from the HEADSTAGE connector BRIDGE BALANCE unit The BRIDGE BALANCE unit consists of 21 100 MQ 10 MQ range switch and 22 BRIDGE BALANCE potentiometer 21 100 MQ 10 MQ range switc2. 0 toggle switch to disable the gated stimulus set by STEP SIZE 7 and gated by GATE TTL STEP SIZE 28 or to select the polarity of the gated stimulus gated stimulus positive 0 gated stimulus disabled gated stimulus negative 28 GATE TTL STEP SIZE connector With this input a current step gated stimulus can be generated set by the digital potentiometer STEP SIZE 7 and the polarity switch 27 This current step is gated by a positive digital pulse 3 5 V applied to the BNC connector Two examples are given in Figure 4 The duration of the current step is determined by the duration of the gating signal The amplitude of the current step is set by STEP SIZE 7 input voltage signal gt 3 V output current signal d U Loe to U L aman UUU Figure 4 input output relation using GATE TTL STEP SIZE 29 CURRENT OUTPUT connector BNC connector monitoring the stimulating current passed through the electrode sensitivity 0 1 V nA resistance 50 Q version 1 9 page 13 BA 01X User Manual 31 ELECTRODE RESISTANCE TEST push button Push button for testing the resistance of the electrode When this button is pushed DISPLAY 2 shows the electrode resistance in MQ see also 3 The selected mode is indicated by the MQ LED 3 The resistance is measured accurately regardless of the correct setting of other front panel elements such as OFFSET BRIDGE BALANCE etc see also Important note below
3. Caution When the ELECTRODE RESISTANCE push button is pressed the BA 01X automatically applies current pulses of 1 nA to the electrode Therefore it should not be used during recordings from cells since this current may stimulate or damage the cell Important With high resistance electrodes ReL gt 20 MQ the displayed value is dependent on the setting of the capacitance compensation POTENTIAL OUTPUT unit The OUTPUT unit consists of 32 POTENTIAL OUTPUT FROM HEADSTAGE connector 33 POTENTIAL OUTPUT GAIN switch and 34 POTENTIAL OUTPUT mV connector POR NI CJ ROM EADTIAGE Vv 32 POTENTIAL OUTPUT FROM HEADSTAGE connector BNC connector monitoring the recorded membrane potential This signal is scaled in V and comes directly from the headstage 1 e it 1s not amplified 33 POTENTIAL OUTPUT GAIN switch Switch to set the gain of the POTENTIAL OUTPUT mv 34 The measured potential at the electrode tip is multiplied by a factor of 10 x10 or 100 x 100 34 POTENTIAL OUTPUT mV connector BNC connector monitoring the recorded potential with a gain set by the POTENTIAL OUTPUT GAIN switch 33 25 GROUND connector e Banana jack that is linked to the internal system ground which has no connection to the 19 cabinet and the mains ground to avoid ground loops version 1 9 page 14 BA 01X User Manual 3 3 Description of the Rear Panel Figure 5 BA 01X r
4. or disable off CURRENT INPUT via 0 1 nA V connector Hint To avoid interferences always switch to off position if the INPUT is not used 26 CURRENT INPUT 0 1 nA V connector Analog input BNC connector for application of signals from an external stimulus source The voltage signal that is connected here is transformed to a proportional current at the electrode with a sensitivity of 0 1 nA V 1 e an input voltage of 5 V is transformed to an output current of 0 5 nA The signal form remains unchanged see also 24 and Figure 3 Very Important If switch 10 is set to x10 all current input signals are multiplied by the factor of 10 1 e STIMULUS INPUT 1 nA V is then 10 nA V and 0 1 nA V is 1 nA V respectively Important The current injected through the electrode is always the sum of the input signal at CURRENT INPUT 24 or 26 the holding current set by HOLDING CURRENT 11 and switch 12 and the gated stimulus set by STEP SIZE 28 and switch 27 version 1 9 page 12 BA 01X User Manual gated stimulus unit The gated stimulus unit consists of 7 STEP SIZE digital potentiometer 27 0 switch STEP SIZE switch and 28 GATE TTL connector 7 STEP SIZE digital potentiometer Digital potentiometer to set the amplitude of the gated stimulus Range dependent on the setting of the CURRENT RANGE switch 9 x1 9 99 nA resolution 10 pA x10 99 9 nA resolution 100 pA 27 0 switch STEP SIZE switch
5. of Individual Neurons in Situ Extra and Intracellular Recording in U Windhorst and H Johansson eds Modern Techniques in Neuroscience Research Springer Berlin New York I Maier N Nimmrich V amp Draguhn A 2003 Cellular and network mechanisms underlying spontaneous sharp wave ripple complexes in mouse hippocampal slices J Physiol 550 873 887 I Mayer Waarden K 1975 Einf hrung in die biologische und medizinische Me technik Schattauer Verlag Stuttgart I Mock M Butovas S amp Schwarz C 2006 Functional unity of the ponto cerebellum evidence that intrapontine communication is mediated by a reciprocal loop with the cerebellar nuclei J Neurophysiol 95 3414 3425 I Neher E 1974 Elektrische Me technik in der Physiologie Springer Verlag Berlin J Nimmrich V Maier N Schmitz D amp Draguhn A 2005 Induced sharp wave ripple complexes in the absence of synaptic inhibition in mouse hippocampal slices Journal of Physiology 563 663 670 version 1 9 page 32 BA 01X User Manual I Ogden DC 1994 Microelectrode Techniques The Plymouth Workshop Handbook Second Edition The Company of Biologists Limited Cambridge I Prinz A A and P Fromherz 2000 Electrical synapses by guided growth of cultured neurons from the snail Lymnaea stagnalis Biol Cybern 82 L1 L5 LJ Prinz A A amp Fromherz P 2003 Effect of neuritic cables on conductance estimates for remote electrical syn
6. of passive elements i e resistors that simulate the resistance of the cell membrane and the electrodes and capacitances that simulate the capacitance of the cell membrane A switch allows simulation of two different cell types a cell with 50 MQ and 22 pF CELL 1 represents an astrocyte like cell or a small cell with 200 MQ membrane resistance and 100 pF membrane capacitance CELL 1 represents an neuron like cell or Electrode immersed into the bath or SEAL formation can be mimicked as well The headstage of the amplifier can be connected to one of two different types of electrodes see below 6 1 Cell Model Description ELC MOD le LV GROUND Ra 1kO 10MO Ls E 1 CELL 2 E GROUND 200MQ END 2 100pF CELL 1 a T 50MQ EL 160 29 OF SOMO e 3 npi electronic GmbH D 71732 Tamm Germany www npielectronic com Figure 7 passive cell model 1 3 connectors for the headstage 1 electrode resistance 50 MQ 3 electrode resistance 10 MQ 2 GND ground connector to be connected to GND jack of the headstage 4 CELL switch for cell membrane representing a membrane of either 50 MQ and 22 pF CELL 1 or 200 MQ and 100 pF CELL 2 S In GROUND upper position the electrodes are connected to ground via a 1 kQ resistor In SEAL lower position are connected to a 1 GQ resistor simulating the formation of a GIGASEAL with a patch electrode version 1 9 page 18 BA 01X User Manual Whole
7. of the BA 01X system consisting a standard headstage and standard calibrations of bridge balance electrode resistance display range etc Other configurations are available e g if the BA 01X system is used only for whole cell patch clamp recordings with suction electrodes the BA 01X system can be delivered with adapted calibrations and a low noise low bias current headstage see Optional accessories in chapter 2 For details contact npi 3 1 System Description The npi BA 01X intracellular recording systems are precise current clamp instruments with a bridge circuit to compensate for the resistance of the recording intracellular electrode For current injection and potential recording a very high impedance voltage to current converter with a special input capacitance compensation circuit is used For methodical reviews see Lalley et al 1999 Richter et al 1996 Ogden 1994 and Boulton et al 1990 version 1 9 page 5 BA 01X User Manual The system consists of standard desktop cabinet and a headstage which should be placed close to the recording site The recording electrode is connected to the headstage via an electrode holder see also Figure 6 In some setups there is no space for placing the headstage very close to the recording site In that case the electrode holder can be connected to the headstage via an electrode adapter see Optional accessories in chapter 2 All electrode connectors use a driven shield approach for d
8. time constant of the cell membrane VreL potential drop at Rer see also Figure 11 version 1 9 page 28 BA 01X User Manual 8 2 Sample Experiment using a Suction Patch Electrode If suction patch electrodes are used for whole cell recordings they are usually called pipettes Thus in this subchapter pipette means suction electrode to amplifier gt EL electrode Sy P p stray aN ground cell el Si ME R ground Figure 14 Model circuit for whole cell patch clamp recording using a suction electrode Cm membrane capacitance Cstray electrode stray capacitance Rez electrode resistance Rm membrane resistance LJ Prepare the setup and proceed as described in the previous subchapter 8 1 until you have selected a cell Before immersing the pipette into the bath apply slight positive pressure to the pipette to prevent settling of particles at the tip 1 Apply test pulses to the pipette about 10 pA The resulting voltage signals at the pipette are very small 50 uV with a 5 MQ electrode I Approach the cell until the voltage signal changes a Figure 15 Often you can observe a slight dent in the cell membrane I Release pressure from the pipette Now forming of the seal is indicated by the voltage deflections getting much larger I If the seal does not form apply gentle suction to the pipette until a gigaseal is established b Figure 15 L Apply stronger suction to the pipe
9. AgCl coating of the silver wire in the agar bridge are damaged 3 There is an unwanted GND bridge e g caused by a leaky bath 4 The headstage or the amplifier has an error Solutions 1 Chloride the silver wire again 2 Exchange the pellet or chloride the silver wire in the agar bridge 3 Try to find the GND bridge and disconnect it e g by sealing the bath 4 Contact npi Problem 2 Even if no stimulus is given a current flows through the electrode Possible reason 1 The BIAS current is not adjusted Solution 1 Adjust the BIAS current according the procedure described in chapter 7 1 Problem 3 The system oscillates Possible reason 1 The capacitance of the electrode is overcompensated Solution 1 Turn the CAPACITY COMPENSATION potentiometer 30 Figure 1 to the most left position and compensate the input capacitance again Problem 4 With the cell model connected the ReL display does not show the correct value within a tolerance of 2 Possible reasons 1 The capacitance of the electrode is not compensated using the 100 MQ electrode 2 The headstage has an error Solution 1 Turn the CAPACITY COMPENSATION potentiometer 30 Figure 1 to the most left position and compensate the input capacitance again 2 Contact npi version 1 9 page 31 BA 01X User Manual Problem 5 The amplifier does not provide any current Possible reason 1 The OSCILLATION SHUT OFF circuit is on LED 30 Figure 1 is re
10. Electronic A Instruments for the Life Sciences pease jade Te OPERATING INSTRUCTIONS AND SYSTEM DESCRIPTION FOR THE BA 01X INTRACELLULAR BRIDGE MODE AMPLIFIER VERSION 1 9 npi 2014 npi electronic GmbH Bauhofring 16 D 71732 Tamm Germany Phone 49 0 7141 9730230 Fax 49 0 7141 9730240 supportOnpielectronic com http www npielectronic com BA 01X User Manual Table of Contents Abots Ni a 3 eSa y RESU ONS iea E E R 4 2 ASE DADOS aera a a a a a oa 5 Di GS r E 5 Feke DA e UP o EOI e 5 2 Description Of ne Front Panel id 6 5 3 DESCANUIOnoOL Ine Rear Panels 15 de ACS E 16 Als Head sta ce Ele MOS A ies 16 di De tna UP ie BAKO I aida 17 0 Passive Cell Model ii icete les iaeids 18 OL Cell Model Desorption a Ai hs 18 6 2 Connections ANG Operas sae se cotins eee EE 19 Ta Toestand TUS Procedu S a ARS ARA O 21 dike Headstage Bias Current AMO ds zi 12 Ofset Compensation rl AR Pap 13 Capacitance COMPpPensatt ON ice soxsiowensscics nase deren eles ds 22 eke ASICS A salen byadsauiadeivoneenasseniabeuet sundsendasaiecnay 24 Die RIE COGS SS CLEC OI ug toes ce asic ac a a na icace tease casa 24 Sample Experimenta anidan 26 8 1 Sample Experiment using a Sharp Electrode cccccccoocooonncnnnnnnnnnnnnnonnnnnnnnnnnnnnninnnnss 26 8 2 Sample Experiment using a Suction Patch Electrode occoooooooocnnnnnnnnnnnonanonnnns 29 De TOUS NOIA ipda 31 10 DI TO cr o scare ee ce oes eee cere 32 11 EM d
11. Electrostatic discharge can be avoided by touching a grounded metal surface when changing or adjusting sensors Always turn power off when adding or removing modules connecting or disconnecting sensors headstages or other components from the instrument or 19 cabinet TEMPERATURE DRIFT WARM UP TIME All analog electronic systems are sensitive to temperature changes Therefore all electronic instruments containing analog circuits should be used only in a warmed up condition 1 e after internal temperature has reached steady state values In most cases a warm up period of 20 30 minutes is sufficient HANDLING Please protect the device from moisture heat radiation and corrosive chemicals version 1 9 page 4 BA 01X User Manual 2 BA 01X Components The following items are shipped with the BA 01X system BA 01X amplifier Headstage Ground connector for headstage 2 6 mm Power cord User manual SNNNN Optional accessories gt Electrode holder gt Suction patch electrode holder Electrode holder adapter for mounting to a micromanipulator electrode holder Remote switch for penetration unit Active cell model Passive cell model see Figure 7 Low noise low bias current headstage with a reduced current range 10 headstage 1 e maximal current is 1 2 nA or 12 nA respectively Headstage with differential input ee yesh 3 BA 01X System This manual is related to the standard configuration
12. I Shepherd G M G amp Svoboda K 2004 Precise Development of Functional and Anatomical Columns in the Neocortex Neuron 42 789 801 I Joshi S amp Hawken M J 2006 Loose patch juxtacellular recording in vivo A method for functional characterization and labeling of neurons in macaque VI J Neurosci Methods 156 37 49 I Khaliq Z M amp Raman I M 2005 Axonal Propagation of Simple and Complex Spikes in Cerebellar Purkinje Neurons J Neurosci 25 454 463 I Klausberger T Marton L F Baude A Roberts J D Magill P J amp Somogyi P 2004 Spike timing of dendrite targeting bistratified cells during hippocampal network oscillations in vivo Nature Neuroscience 7 41 47 I Nunemaker C S DeFazio R A amp Moenter S M 2003 A targeted extracellular approach for recording long term firing patterns of excitable cells a practical guide Biol Proced Online 5 53 62 www biologicalprocedures com I Pinault D 1996 A novel single cell staining procedure performed in vivo under electro physiological control morpho functional features of juxtacellularly labeled thalamic cells and other central neurons with biocytin or Neurobiotin J Neurosci Methods 65 113 136 version 1 9 page 33 BA 01X User Manual I Rathenberg J Nevian T amp Witzemann V 2003 High efficiency transfection of individual neurons using modified electrophysiology techniques J Neurosci Methods 126 91 98 I Robe
13. SHUT OFF LED 6 DISABLED RESET switch and the 30 THRESHOLD potentiometer 5 OSCILLATION SHUT OFF LED Indicates whether the OSCILLATION SHUT OFF circuit is active LED red or not LED green 6 DISABLED RESET switch Switch to DISABLE the OSCILLATION SHUT OFF unit or RESET the circuit RESET is for resetting the circuit after previous activation After resetting the OSCILLATION SHUT OFF unit is active again 30 THRESHOLD potentiometer Control to set the activation THRESHOLD of the OSCILLATION SHUT OFF circuit potentiometer linear clockwise range 0 1200 mV Note If the OSCILLATION SHUT OFF unit is active the output of the amplifier to the headstage 1s disabled Potential measurement works version 1 9 page 8 BA 01X User Manual Important The capacity compensation for the electrode does NOT work 1f the oscillation shut off circuit 1s activated This may lead to an incorrect reading of the electrode resistance see also 31 especially when electrodes with high resistances are used 8 CURRENT nA display Display for the electrode current in nA Scaling is dependent on the position of the CURRENT RANGE switch 9 xl XX XX nA x10 XXX X nA CURRENT RANGE unit The CURRENT RANGE unit consists of 9 CURRENT RANGE LED and 10 CURRENT RANGE switch 9 CURRENT RANGE LED LED indicating the actual current range of the amplifier LED ON BA 01X is in x10 range LED OFF BA 01X is in x1 range 10 C
14. URRENT RANGE switch Switch for setting the current range of the amplifier x1 max 12 nA into 1 GQ x10 max 120 nA into 100 MQ HOLDING CURRENT unit The HOLDING CURRENT unit consists of 12 HOLDING CURRENT nA potentiometer and 12 0 switch holding current switch 11 HOLDING CURRENT nA potentiometer Control for generating a constant current holding current ten turn potentiometer clockwise calibrated in nA Imax 10 nA in x1 current range or 100 nA in x10 current range The polarity of this holding current is set by toggle switch 12 12 0 switch holding current switch Switch to disable holding current generation or to set the polarity of the holding current current positive 0 holding current disabled current negative version 1 9 page 9 BA 01X User Manual 13 BIAS bias current potentiometer Potentiometer for cancellation of the output current BIAS current of the headstage ten turn potentiometer symmetrical 1 e 0 pA 5 on the dial range current range x1 and x10 200 pA see chapter 7 1 The PENETRATION unit consists of 14 ELECTR CLEAR switch 15 BUZZ push button 19 BUZZ DURATION potentiometer and 20 BUZZ REMOTE connector 5 ELECTR CLEAR switch Momentary switch for activating the ELECTRODE CLEAR circuit that can be used to clean the tip of the electrode by passing large amounts of positive or negative currents The circuit is operated by pushing
15. apses J Neurophysiol 89 2215 2224 JI Purves R D 1981 Microelectrode Methods for Intracellular Recording and Ionophoresis London Academic Press LJ Rokem A Watzl S Gollisch T Stemmler M Herz A V amp Samengo I 2006 Spike timing precision underlies the coding efficiency of auditory receptor neurons J Neurophysiol 93 2541 2552 I Schaette R Gollisch T amp Herz A V M 2005 Spike Train Variability of Auditory Neurons in vivo Dynamic Responses Follow Predictions from Constant Stimuli Journal of Neurophysiology 93 3270 3281 L Schoen L Fromherz P 2007 The Mechanism of Extracellular Stimulation of Nerve Cells on an Electrolyte Oxide Semiconductor Capacitor Biophys J 92 1096 1111 d Vogel A Hennig R M amp Ronacher B 2005 Increase of neuronal response variability at higher processing levels as revealed by simultaneous recordings Journal of Neurophysiology 93 3548 3559 I Zeck G and P Fromherz 2001 Noninvasive neuroelectronic interfacing with synaptically connected snail neurons immobilized on a semiconductor chip PNAS Vol 98 no 18 10457 10462 Juxtasomal Filling Loose Patch Techniques General J Auger C amp Marty A 2000 Topical Review Quantal currents at singlesite central synapses J Physiol 526 1 3 11 I Barbour B amp Isope P 2000 Combining loose cell attached stimulation and recording J Neurosci Methods 103 199 208 I Bureau
16. cell Patch share Microelectrode Driven Shield BNC connector BNC connector Re 10 MQ Rg 90 MQ O Q CELL 2 CELL O O Rerounn seal Rm Cm Cm Rm 1 kQ 1 CQ 200 MQ 100 pF 22 pF 50 MQ Figure 8 Schematic diagram of the passive cell model 6 2 Connections and Operation It is assumed that all connections are built as described in chapter 5 Checking the configuration Y Turn POWER switch of the amplifier off a For simulation of an experiment using a suction electrode 1 Connect the BNC jack labeled 10MQ of the cell model to the BNC connector Per of the headstage b For simulation of an experiment using a sharp electrode Y Connect the BNC jack labeled 50MQ of the cell model to the BNC connector Perr at the headstage For headstages with SMB connector use the supplied SMB to BNC adapter version 1 9 page 19 BA 01X User Manual For a and b 1 Connect GND of the cell model to GND of the headstage Important When using the differential headstage optional the REF connector must not be left open It must be connected to ground Simulation of electrode in the bath _I Set switch 4 Figure 7 to the lower position Y Set switch 5 Figure 7 to GROUND position The 1 kQ resistor simulates the resistance of the bath solution This can be used to train cancellation of offsets using the bridge balance and using the capacity compensation Simulation of SEAL formation _I Set switch 4 Figure 7 to the lower p
17. d Solution 1 Turn the CAPACITY COMP potentiometer 17 Figure 1 to the most left position and compensate the input capacitance again 2 RESET the OSCILLATION SHUT OFF circuit using switch 32 Figure 1 LED 30 Figure must become green 3 Compensate the input capacitance again 10 Literature Bridge amplifier recording I Behrend O Branoner F Zhivkov Z amp Ziehm U 2006 Neural responses to water surface waves in the midbrain of the aquatic predator Xenopus laevis laevis Eur J Neurosci 23 729 744 I Burrell B D amp Sahley C L 2004 Multiple forms of long term potentiation and long term depression converge on a single interneuron in the leech CNS J Neurosci 24 4011 4019 I Burrell B D Sahley C L 2005 Serotonin Mediates Learning Induced Potentiation Of Excitability Journal of Neurophysiology 94 4002 4010 I Gollisch T Schutze H Benda J amp Herz A V 2002 Energy integration describes sound intensity coding in an insect auditory system J Neurosci 22 10434 10448 _I Hutzler M Lambacher A Eversmann B Jenkner M Thewes R amp Fromherz P 2006 High resolution multi transistor array recording of electrical field potentials in cultured brain slices J Neurophysiol I Kettenmann H amp Grantyn R eds 1992 Practical Electrophysiological Methods Wiley Liss New York I Lalley P M A K Moschovakis and U Windhorst 1999 Electrical Activity
18. d to use the gated stimulus unit Connect a store oscilloscope or a data recording device i e a computer with data acquisition system to the POTENTIAL OUTPUT and to the CURRENT OUTPUT triggered from the stimulation device Set the desired gain at the potential range switch 11 Figure 1 Before using the BA 01X always make the basic settings to avoid oscillations Basic settings m m E Turn all controls to low values less than 1 and the OFFSET in the range of 5 zero position see chapter 3 2 Set the CURRENT RANGE switch 10 Figure 1 to x1 Turn POWER switch on Now the BA 01X is ready for an initial check with the cell model version 1 9 page 17 BA 01X User Manual 6 Passive Cell Model The BA 01X can be ordered with a passive cell model as an optional accessory An active cell model is also available by request for ref see Draguhn et al 1997 The passive cell model is designed for use with single electrode amplifiers BA series ELC series to check the function of the instrument in the following circumstances 1 just after unpacking to see whether the instrument has been damaged during transport or 2 to train personnel using the instrument or 3 in case of trouble see also chapter 9 to check which part of the setup does not work correctly e g to find out whether the amplifier or headstage 1s damaged or something is wrong with the electrodes or holders etc The passive cell model consists only
19. des can be improved by breaking the tip or by using the BUZZ or ELECTRODE CLEAR facilities of the amplifier undercompensated potential mV 0 50 100 150 200 250 300 350 400 time ms overcom pensated potential mV time ms compensated potential mV 3 T T T T T T 0 50 100 150 200 200 300 350 400 time ms potential Figure 10 Tuning of the BRIDGE BALANCE using 100 MQ resistor version 1 9 page 25 BA 01X User Manual 8 Sample Experiments In the following the basics of a simple experiment are described either using a sharp or a suction electrode It is assumed that all connections are built as described in chapter 0 Before starting remove the cell model 8 1 Sample Experiment using a Sharp Electrode Rep to amplifier electrode SS cell Ca e p stray HOY S ground Ss Co Ra ground Figure 11 Model circuit for intracellular recording using a sharp electrode Cm membrane capacitance Cstray electrode stray capacitance Reg electrode resistance Rm membrane resistance 1 Connect the electrode cable holder to the BNC connector and the Ag AgCl pellet or the agar bridge for grounding the bath with GND at the headstage 1 Make the basic settings see chapter 0 Again It is of major importance that the BA 01X systems are used only in warmed up condition 1 e 30 minutes after turning power on J Adjust BIAS CURRENT to zero if n
20. e occurring voltage deflection potential drop at ReL affects the recording of membrane potential Therefore this deflection must be compensated carefully by means of the BRIDGE BALANCE control This control is calibrated in MQ and has two ranges selected by a RANGE switch 21 Figure 1 With the cell model connected or the electrode in the bath the BRIDGE BALANCE control is turned on clockwise until there is no artifact on the POTENTIAL OUTPUT see Figure 10 d Make the basic settings at the amplifier see chapter 0 Y Connect a cell model or immerse the electrode into the bath as deep as necessary during the experiment Ld Tune the OFFSET to zero see chapter 7 2 and compensate the input capacitance see chapter 7 3 This is very important since a badly compensated input capacitance prevents setting the BRIDGE BALANCE to correct values 1 Determine the electrode resistance using the ELECTRODE RESISTANCE switch and set the BRIDGE BALANCE RANGE switch 21 Figure 1 accordingly Y Apply current pulses to the electrode either using an external stimulator via the CURRENT INPUT connector 24 26 Figure 1 or by using the gated stimulus unit L Watch the POTENTIAL OUTPUT at the oscilloscope and adjust the BRIDGE BALANCE as shown in Figure 10 using the BRIDGE BALANCE potentiometer 22 Figure 1 After adjustment you should see a straight voltage trace without artifacts caused by the potential drop at Ret Figure 10 illust
21. ear ne view the numbers are related to those in the text below 1 Mains connector Plug for connecting the BA 01X to mains 2 Voltage SELECTOR Rotary switch for selecting the mains voltage 110 V 120 V 220 V 240 V Caution Always switch to the appropriate voltage before connecting the BA 01X to power 3 FUSE holder Holder for the line fuse For changing the fuse rotate the holder counter clockwise using a screw driver The appropriate fuse type is listed above the holder 4 CHASSIS This connector is linked to mains ground green yellow wire protective earth 5 GROUND This connector is linked to the internal system ground which has no connection to the 19 cabinet CHASSIS and the mains ground to avoid ground loops MODES of OPERATION connectors 6 Ret connector BNC connector for connecting a TTL signal that activates the electrode resistance test see also 31 Figure 1 TTL HI Rez on TTL LOW Rez off 7 x10 MODE connector BNC connector for connecting a TTL signal that activates the x10 current mode see also 10 Figure 1 TTL HI x10 current mode TTL LOW x1 current mode REMOTE connector 8 BUZZ connector BNC connector for connecting a TTL signal that activates the BUZZ function see also 20 Figure 1 TTL HI BUZZ on TTL LOW BUZZ off version 1 9 page 15 BA 01X User Manual 4 Headstage The BA 01X comes with the standard headstage range 12 nA voltage range x1 o
22. ease contact npi for details Ground provides system ground and is linked to the bath via an agar bridge or a Ag AgCl pellet The headstage is attached to the amplifier with the headstage cable see 4 Figure 6 and a 8 pole connector The headstage is mounted to a holding bar that fits to most micromanipulators or optionally to a mounting plate or a dovetail adapter Note The shield of the BNC connector is linked to the driven shield output and must not be connected to ground Caution Please always adhere to the appropriate safety precautions see chapter 1 Please turn power off when connecting or disconnecting the headstage from the HEADSTAGE connector version 1 9 page 16 BA 01X User Manual 5 Setting up the BA 01X The following steps should help you set up the BA 01X correctly Always adhere to the appropriate safety measures see chapter 1 After unpacking the BA O1X is attached to the setup by assembling the electrical connections It is assumed that a cell model will be attached The connection of the Ag AgCl pellet or the agar bridge for grounding the bath is described in chapter 8 Electrical connections E E E E Turn POWER off Plug the instrument into a grounded outlet Connect the headstage to the HEADSTAGE connector 18 Figure 1 at the BA 01X Connect a cell model see chapter 6 Connect a digital analog timing unit or a stimulation device to CURRENT INPUT or to GATE TTL STEP SIZE if you inten
23. ecessary see chapter 7 1 I Reconnect the STIMULUS INPUT and or the GATE TTL STEP SIZE and put an electrode into the electrode holder 1 Immerse the electrode into the bath not in a cell as deep as necessary during the experiment Test the capability of the electrode to carry current see chapter 7 4 compensate the potential offset see chapter 7 2 measure the electrode resistance see 10 chapter 3 2 and compensate the input capacitance see chapter 7 3 and Figure 9 I Enable the OSCILLATION SHUT OFF unit and set the THRESHOLD so that the OSCILLATION SHUT OFF unit activates if the system begins to oscillate Test this by version 1 9 page 26 BA 01X User Manual overcompensating the electrode capacitance in several positions of the THRESHOLD potentiometer 1 Now the system is preadjusted for measurements Find a cell L Approach the desired cell There are several indications that the electrode is very close to the cell membrane the electrode resistance increases the bridge balance appears undercompensated extracellular action potentials APs are recorded the acoustic monitor signal changes I Set the BUZZ DURATION potentiometer to one fourth and apply a BUZZ to the electrode I If you are lucky the tip of the electrode is now inside the cell I If necessary readjust the BRIDGE BALANCE as shown in Figure 12 L You read the membrane potential and can apply current pulses to the cell After penetration the vo
24. ecida 35 E 37 version 1 9 page 2 BA 01X User Manual About this Manual This manual should help to setup and use the BA 01X system correctly and to perform reliable experiments If you are not familiar with the use of instruments for intracellular recording of electrical signals please read the manual completely The experienced user should read at least chapters 1 3 3 3 0 and 7 Important Please read chapter 1 carefully It contains general information about the safety regulations and how to handle highly sensitive electronic instruments Signs and conventions In this manual all elements of the front panel are written in capital letters as they appear on the front panel System components that are shipped in the standard configuration are marked with Y optional components with In some chapters the user is guided step by step through a certain procedure These steps are marked with U1 Important information and special precautions are highlighted in gray Abbreviations Cm cell membrane capacitance Cstray electrode stray capacitance GND ground Imax maximal current Rm cell membrane resistance Rei electrode resistance Tcm time constant of the cell membrane VreEL potential drop at Rex version 1 9 page 3 BA 01X User Manual 1 Safety Regulations VERY IMPORTANT Instruments and components supplied by npi electronic are NOT intended for clinical use or medical purposes e g for diagnosis or treatment of h
25. etails of this approach see Ogden 1994 to minimize the effect of the connecting cables In addition all headstages are equipped with a ground connector providing system ground The standard system is equipped with a headstage capable of injecting a maximal current of approximately 12 nA 120 nA into a resistance of 100 MQ 10 MQ dependent on the preset current range With this headstage the system can be used either with high resistance electrodes for intracellular recordings or with low resistance suction electrodes for whole cell patch clamp recordings To cover all the needs of electrophysiological research all systems have a large variety of operation and control elements such as cell penetration mode BUZZ ELECTRODE CLEAR facility ten turn controls for BRIDGE BALANCE CAPACITANCE COMPENSATION OFFSET and HOLDING CURRENT an automated electrode resistance test digital displays for potential current and electrode resistance a GATE and linear CURRENT STIMULUS INPUT An extended CURRENT RANGE x10 allows electroporation of single cells for non invasive juxtacellular filling of cells with dyes or plasmids 3 2 Description of the Front Panel In the following description of the front panel elements each element has a number that is related to that in Figure 1 The number is followed by the name in uppercase letters written on the front panel and the type of the element in lowercase letters Then a short description of the eleme
26. h Switch to set the range of the BRIDGE BALANCE potentiometer 100 MQ position O MQ to 1000 MQ 10 MQ position O MQ to 100 MQ 22 BRIDGE BALANCE MQ potentiometer If current is passed through the recording electrode the potential deflection caused at the electrode resistance is compensated with this control ten turn potentiometer clockwise calibrated in MQ range set by switch 21 see also chapter 7 4 version 1 9 page 11 BA 01X User Manual CURRENT INPUT unit The CURRENT INPUT unit consists of 23 25 on off switches 24 1 nA V connector and 26 0 1 nA V connector 23 on off switch Switch to enable on or disable off CURRENT INPUT via 1 nA V connector To avoid interferences always switch to off position 1f the INPUT is not used 24 CURRENT INPUT 1 nA V connector Analog input BNC connector for application of signals from an external stimulus source The voltage signal that is connected here is transformed to a proportional current at the electrode with a sensitivity of 1 nA V 1 e an input voltage of 5 V is transformed to an output current of 5 nA The signal form remains unchanged Two examples are given in Figure 3 The amplitude of the output current signal current stimulus is determined by the amplitude of the input voltage signal input voltage signal output current signal J UOU L gt Ll L Figure 3 input output relation using CURRENT INPUT 25 on off switch Switch to enable on
27. lly with the OFFSET control 16 Figure 1 before recording from a cell When adjusting the OFFSET make sure that no current flows through the electrode Thus it is recommended to disconnect CURRENT INPUT and to disable GATE TTL STEP SIZE and the HOLDING CURRENT unit see chapter 3 2 If a cell model is connected the OFFSET control should read a value around 5 otherwise it is likely that the headstage or the amplifier is damaged 7 3 Capacitance Compensation High resistances of electrodes and stray capacitances Cstray form a low pass filter which deteriorates the shape of recorded intracellular signals see also Figure 11 The frequency response bandwidth of the amplifier is improved considerably by using the capacitance compensation function This function is based on positive feedback negative capacitance circuit The tuning of the capacitance compensation control is performed using pulses applied to the CURRENT INPUT or pulses provided by the electrode resistance test circuit With the cell model connected or the electrode in the bath the CAPACITY COMP control is turned clockwise until there is no artifact on the POTENTIAL OUTPUT see Figure 9 1 Make the basic settings at the amplifier see chapter 0 Y Connect a cell model or immerse the electrode into the bath as deep as necessary during the experiment I Tune the OFFSET to zero see chapter 7 2 I Push the ELECTRODE RESISTANCE TEST button 31 Figure 1 or ap
28. ltage responses of the cell to the test pulses should reflect the cell membrane resistance and time constant I Start the experiment overcompensated compensated undercompensated 5 mv 20 ms Figure 12 Adjustment of the bridge balance after penetrating a cell version 1 9 page 27 BA 01X User Manual A uncompensated potential mV current nA 100 gt r 3 0 80 C Tem 7 stray ye 2 5 Y 60 REL a 2 0 40 mm 1 5 20 V REL 1 0 0 R EN 20 gt PoP 40 T T T rT 0 0 0 20 40 60 80 100 120 140 160 B time ms Cstray compe nsate d potential mV current nA 80 gt 7 3 0 70 5 25 60 50 20 40 1 5 30 20 1 0 10 0 5 0 10 r 0 0 T 0 20 40 60 80 100 120 140 160 time ms Cstray and Vre compensated potential mV current nA 60 7 3 0 ue tom 50 2 5 40 2 0 30 ee Tom 45 20 7 1 0 10 0 5 0 0 0 o 20 40 60 80 100 120 140 160 time ms potential current Figure 13 Artifacts caused by the recording electrode The measurements were done using a cell model with 100 MQ membrane resistance 100 pF membrane capacitance and 100 MQ electrode resistance A Cstray and VreL not compensated bridge not balanced B Cstray compensated and VreL not compensated C Cstray and VreL compensated bridge balanced Cm membrane capacitance Cstray electrode stray capacitance Ret electrode resistance Rm membrane resistance Tcm
29. nt is given Some elements are grouped in functional units e g BUZZ unit and are described as units regardless of the order of numbers version 1 9 page 6 BA 01X User Manual 0 0 OCD 20 70 A 9 O P 80 70 AN HEADSTAGE REMOTE O E O ES T O N 2 E wee gt O a rs Sos Oot Y Lu 1 nAV aaa D y Eta STIMULUS INPUT A STIMULUS INPUT 0 1 nA V CURRENT RANGE STEP SIZE HOLDING CURRENT nA CURRENT nA O CURRENT eae OUTPUT GATE TTL OSCILLATION SHUT OFF DISABLED RESET THRESHOLD ELECTRODE RESISTANCE TEST O POTENTIAL OUTPUT FROM HEADSTAGE V JE 33 x 100 x10 POTENTIAL RESISTANCE POTENTIAL OUTPUT mV POTENTIAL OUTPUT GAIN BA 01X npi 2 8 eS Opo O O Figure 1 BA 01X front panel view the numbers are related to those in the text below GROUND POWER version 1 9 page 7 BA 01X User Manual 1 POWER pressure switch POWER Switch to turn POWER on switch pushed or off switch released 2 POTENTIAL RESISTANCE display Display for the recorded potential in mV XXX mV or the electrode resistance in MQ XXX MQ 1 e 100 correspond to 100 MQ selected by push button 31 3 MQ LED ay LED indicating that the unit of display 2 is MQ 4 mV LED LED indicating that the unit of display 2 is mV OSCILLATION SHUT OFF unit The OSCILLATION SHUT OFF unit consists of 5 OSCILLATION
30. osition ld Set switch 5 Figure 7 to SEAL position The 1 GQ resistor simulates the SEAL resistance when forming a GIGASEAL in patch clamp experiments Simulation of intracellular recording Intracellular recordings can be mimicked with one of two cells with different properties Use the 50 MQ electrode connector 1 Figure 7 for an experiment with sharp electrodes or the 10 MQ electrode connector 3 Figure 7 for simulating an experiment with patch electrodes I Switch the CELL membrane switch see 4 Figure 7 to the desired position CELL 1 or CELL 2 3 Turn all controls at the amplifier to low values less than 1 and the OFFSET in the range of 5 zero position and the OSCILLATION SHUTOFF in the DISABLED position _J Turn POWER switch of the amplifier on Now you can adjust the amplifier see below and apply test pulses to the cell model The upper position the CELL membrane switch CELL 1 simulates a cell with a resistance of 50 MQ and a capacitance of 22 pF In the lower position CELL 2 a cell membrane with 200 MQ and 100 pF is simulated version 1 9 page 20 BA 01X User Manual 7 Test and Tuning Procedures Important The BA 01X should be used only in warmed up condition 1 e 20 to 30 minutes after turning power on The following test and tuning procedures are necessary for optimal recordings It is recommended to first connect a cell model to the amplifier to perform some basic adjustments and to get familiar
31. ply pulses to the CURRENT STIMULUS INPUT and watch the POTENTIAL OUTPUT L Compensate the input capacitance as shown in Figure 9 using the CAPACITY COMP potentiometer 17 Figure 1 Figure 9 illustrates the capacitance compensation procedure using a 100 MQ resistor that represents the electrode The pulses were generated using the automated electrode resistance test circuit of the BA 01X The upper diagram shows an undercompensated capacitance In the diagram in the middle the capacitance is slightly overcompensated and in the lower diagram it is well compensated version 1 9 page 22 BA 01X User Manual Important The capacity compensation for the electrode does NOT work if the oscillation shut off circuit 1s activated This may lead to an incorrect reading of the electrode resistance see also 31 especially when electrodes with high resistances are used undercompensated potential mV 250 200 150 100 4 50 4 0 10 20 30 40 50 time ms overcompensated potential mV 600 400 200 O 200 400 600 o 10 20 30 40 50 time ms compensated potential mV 200 5 200 150 100 4 50 4 0 5 i i 3 a A we i 0 10 20 30 40 50 time ms potential Figure 9 Tuning of the capacitance compensation using a 100 MQ resistor version 1 9 page 23 BA 01X User Manual 7 4 Bridge Balance If current is passed through an electrode th
32. r 120 nA voltage range x10 for connecting glass electrodes with high resistances or suction electrodes for whole cell patch clamp recordings with lower resistances via an electrode holder see Figure 6 A low noise low bias current headstage range 1 2 nA voltage range x1 or 12 nA voltage range x10 see also Optional accessories in chapter 2 for very small currents is also available For details contact npi headstage TO See Figure 6 electrode holder optional and headstage of the BA 01X 4 1 Headstage Elements BNC connector for the electrode holder optional REF connector for the reference electrode differential headstage only GND Ground connector headstage cable holding bar A Y Nm The electrode filled with electrolyte is inserted into an electrode holder optional see Figure 6 that fits into the BNC connector of the headstage or into an electrode holder adapter optional see also Optional accessories in chapter 2 The electrical connection between the electrolyte and the headstage is established using a carefully chlorinated silver wire Chlorinating of the silver wire is very important since contact of silver to the electrolyte leads to electrochemical potentials causing varying offset potentials at the electrode deterioration of the voltage measurement etc for details see Kettenmann and Grantyn 1992 For optimal chlorinating of sliver wires an automated chlorinating apparatus ACI 01 is available pl
33. rates the BRIDGE BALANCE procedure using a 100 MQ resistor that represents the electrode The current stimuli were generated using the gated stimulus unit gated by two TTL pulses The amplitude was set to 0 5 nA In the upper diagram the bridge is slightly undercompensated and in the diagram in the middle it is slightly overcompensated The lower diagram shows a well balanced bridge compensated Important BRIDGE BALANCE and CAP COMP must be tuned several times during an experiment since most parameters change during a recording session Figure 13 shows artifacts caused by uncompensated stray capacitance and bridge during recording from a cell It also shows how to cancel these artifacts by tuning with CAP COMP and BRIDGE BALANCE OFFSET deviations can be detected by comparing the readout on the potential display before and after an experiment with the electrode in the tissue but not in a cell 7 5 Electrode Selection Electrodes must be tested before use This is done by applying positive and negative current pulses and by compensating with the BRIDGE BALANCE control Electrodes which show significant changes in resistance rectification cannot be used for intracellular recordings By increasing the current amplitude the capability of the electrode to apply current can be estimated The test current must cover the full range of currents used in the experiment version 1 9 page 24 BA 01X User Manual Sometimes the performance of electro
34. rts W M amp Almers W 1992 Patch Voltage Clamping with Low Resistance Seals Loose Patch Clamp In Rudy B amp Iversen L E eds Ion Channels Methods in Enzymology 207 Academic Press San Diego I Strickholm A 1961 Impedance of a Small Electrically Isolated Area of the Muscle Cell Surface J Gen Physiol 44 1073 1088 Tracer injection juxtasomal filling and extracellular recording d Bruno R M amp Sakmann B 2006 Cortex is driven by weak but synchronously active thalamocortical synapses Science 312 1622 1627 version 1 9 page 34 BA 01X User Manual 11 Technical Data Headstage Input voltage range 1000 mV Operating voltage 15 V Enclosure Size 23 x 70 x 26 mm grounded Holding bar Size length 150 mm Y 8 mm Electrode connector BNC with driven shield Ground connector 2 4 mm connector REF connector optional SMB connector Input resistance gt 10 Q internally adjustable Current range x1 12 nA into 1 GQ Current range x10 120 nA into 100 MQ Electrode parameter controls BIAS range 150 pA current adjustable with trim potentiometer OFFSET range 200 mV ten turn control CAPACITY COMPENSATION range 0 30 pF ten turn control BUZZ overcompensation of capacitance compensation BUZZ duration 2 5 100 ms slightly dependent on the setting of capacitance compensation timer controlled with linear control accessible with remote switch Electrode clear circ
35. se a wire to connect the input of the BNC connector on the headstage to GND of the headstage Do not use the shield of the BNC connector since it is connected to driven shield Ld Tune the OFFSET to zero using the OFFSET control 16 Figure 1 see also chapter 7 2 Y After tuning the OFFSET connect the cell model via the SUBCLICK connector sharp electrode If you do not use a cell model remove the wire and attach a resistor with a value of about 5 to 10 MQ across the same connection I The value displayed at the DISPLAY 2 Figure 1 is related to the BIAS current of the headstage according to Ohm s Law Cancel this voltage by tuning the headstage BIAS current potentiometer 13 Figure 1 version 1 9 page 21 BA 01X User Manual ld Accuracy Now both DISPLAYs potential current the should read 000 Due to the limited resolution of the display unbalanced offsets and thermal drifts an offset of 001 to 002 can occur on the display This small deviation can be trimmed internally but this procedure is necessary only if very small currents in the pA range should be accurately applied 7 2 Offset Compensation If an electrode is immersed into the bath solution an offset voltage will appear even if no current is passed This offset potential is the sum of various effects at the tip of the electrode filled with electrolyte tip potential junction potential etc This offset voltage must be compensated i e set to zero carefu
36. stment 21 BIAS current potentiometer 10 bridge balance 24 25 27 BRIDGE BALANCE unit 11 BUZZ 10 CAPACITY COMPENSATION potentiometer 11 cell model 18 connections and operation 19 description 18 components 5 CURRENT INPUT unit 12 CURRENT RANGE unit 9 electrical connections 17 electrode 22 artifacts 28 capacity compensation 22 offset compensation 22 selection 24 ELECTRODE RESISTANCE TEST 14 front panel view 7 gated stimulus unit 13 version 1 9 general description 5 GROUND connector 14 headstage 16 elements 16 HEADSTAGE connector 11 HOLDING CURRENT unit 9 literature 32 model circuit sharp electrode 26 model circuit suction patch electrode 29 OFFSET potentiometer 11 OSCILLATION SHUT OFF unit 8 PENETRATION unit 10 POTENTIAL OUTPUT unit 14 rear panel 15 safety regulations 4 sample experiments 26 sharp electrode 26 suction patch electrode 29 sealing 30 sharp electrodes 26 suction patch electrodes 29 technical data 35 testing 21 trouble shooting 31 tuning 21 page 37
37. the switch to Imax maximum positive current or Imax maximum negative current The maximum current is dependent on the setting of the current range see also 10 15 BUZZ push button Push button to activate the BUZZ circuit duration set by 19 To facilitate the penetration of the cell membrane the BUZZ circuit is provided which is based on oscillations caused by overcompensating the capacitance compensation system This yields to very powerful high frequency oscillations see Figure 2 19 BUZZ DURATION potentiometer Control to set the duration of the BUZZ potentiometer clockwise range 1 ms to 100 ms The duration is also slightly dependent on the setting of CAPACITY COMP 17 It is effective in both modes REMOTE and BUZZ see also 20 20 BUZZ REMOTE connector BNC connector for operating the BUZZ circuit remotely The remote device is connected via a grounded BNC cable The duration of the BUZZ is dependent on the setting of the BUZZ DURATION potentiometer 19 potential mV 12000 gt 8000 gt 4000 0 4000 8000
38. tte or use the BUZZ unit to brake the cell membrane under the pipette and establish the whole cell configuration The whole cell configuration is established if you see the voltage signal getting smaller again c Figure 15 and you read the expected membrane potential 1 Read the membrane potential and if necessary readjust the BRIDGE BALANCE as shown in 7 4 and Figure 13 I Start the experiment version 1 9 page 29 BA 01X User Manual a close to the E Tere e cell membrane b 10 mV gigaseal formed C whole cell configuration established 5 mV 25 ms Figure 15 Approaching the cell forming a gigaseal and establishing the whole cell configuration version 1 9 page 30 BA 01X User Manual 9 Trouble Shooting In the following section some common problems possible reasons and their solutions are described Important Please note that the suggestions for solving the problems are only hints and may not work In a complex setup it is impossible to analyze problems without knowing details In case of trouble always contact an experienced electrophysiologist in your laboratory if possible and connect a cell model to see whether the problem occurring with electrodes and real cells persists Problem 1 After immersing the electrode into the bath there is an unusual high potential offset Possible reasons 1 The Ag AgCl coating of the silver wire in the electrode holder is damaged 2 The Ag AgCl pellet or Ag
39. uit Application of max DC currents Imax or Imax Bridge balance Adjustable with ten turn control and RANGE switch 0 100 MQ or 0 1000 MQ Electrode resistance test 10 mV MQ obtained by application of rectangular current pulses 1 nA Bandwidth and speed response Full power bandwidth Ret 0 gt 30 kHz rise time 10 90 lt 10 us Ret 100 MQ lt 5 us Ret 5 MQ Outputs Resistance 50 Q Current x1 x 10 BNC connector sensitivity 0 1 V nA Potential BNC connector sensitivity selectable by toggle switch x10 x 100 version 1 9 page 35 BA 01X User Manual Displays Potential XXXX mV max 1999 mV Electrode resistance XXXX MQ max 1999 MQ Current x1 XX XX nA Current x10 XXX X nA Inputs Current stimulus input via BNC connectors sensitivity dependent on preset CURRENT RANGE x InA Vor0 lnA V x10 JI0nA VorlnA V Step gate input via BNC connector gated stimulus with digital control of current step size resolution xl 10pA resolution x10 100 pA polarity selectable with toggle switch holding current range xl 10nA holding current range x10 100nA adjustable with ten turn control Dimensions 19 rackmount cabinet 19 483 mm 10 250 mm 3 5 88 mm Power requirements 115 230 V AC 60 50 Hz fuse 0 4 0 2 A slow 25 W version 1 9 page 36 BA 01X User Manual Index abbreviations 3 accessories 5 basic settings 17 bias current 31 bias current adju
40. umans or for any other life supporting system npi electronic disclaims any warranties for such purpose Equipment supplied by npi electronic must be operated only by selected trained and adequately instructed personnel For details please consult the GENERAL TERMS OF DELIVERY AND CONDITIONS OF BUSINESS of npi electronic D 71732 Tamm Germany 1 2 3 4 5 GENERAL This system is designed for use in scientific laboratories and must be operated only by trained staff General safety regulations for operating electrical devices should be followed AC MAINS CONNECTION While working with npi systems always adhere to the appropriate safety measures for handling electronic devices Before using any device please read manuals and instructions carefully The device is to be operated only at 115 230 Volt 60 50 Hz AC Please check for appropriate line voltage before connecting any system to mains Always use a three wire line cord and a mains power plug with a protection contact connected to ground protective earth Before opening the cabinet unplug the instrument Unplug the instrument when replacing the fuse or changing line voltage Replace fuse only with an appropriate specified type STATIC ELECTRICITY Electronic equipment is sensitive to static discharges Some devices such as sensor inputs are equipped with very sensitive FET amplifiers which can be damaged by electrostatic charge and must therefore be handled with care
41. with these procedures It is assumed that all connections are built as described in chapter 5 Important Except for Headstage bias current adjustment see 7 1 all adjustments described below should be carried out every time before starting an experiment or after changing the electrode 7 1 Headstage Bias Current Adjustment Caution It is important that this tuning procedure is performed ONLY after a warm up period of at least 30 minutes The BA 01X system is equipped with a voltage to current converter with a very high output impedance which is connected to the recording electrode The zero current of this unit is tuned with the BIAS current control 13 Figure 1 chapter 3 2 The tuning procedure must be performed regularly about once a month since the bias current changes over time If very small currents are used in the 10 pA range the procedure must be repeated in shorter intervals The tuning procedure is performed using high value resistors and or a cell model It cannot be performed with an electrode since there are always unknown potentials involved tip potential junction potentials Y Disconnected all input signals except the headstage Put the holding current switch to position 0 0 switch 12 Figure 1 Y Connect the MICROELECTRODE connector of the headstage to ground If parasitic oscillations occur use a 10 kQ resistor for grounding If you use a cell model set 3 in Figure 7 to GROUND Note Please u
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