FSCV Headstage Amplifier (5 megaohm/200 nA/V)

SKU: AC01HS1 Category: Tag:

This Headstage Amplifier is designed for use with the Pine Research WaveNeuro Fast-Scan Cyclic Voltammetry Potentiostat System.  Installation is as simple as “clicking” the adapter onto the headstage cable.  This 200 nA/V (5 MΩ), working driven headstage amplifier is wrapped in blue-colored shrink tubing to differentiate it from our other headstage gains.  This particular adapter is for general purpose FSCV experiments, where typical microelectrodes (~100 μm long cylinder) are used.

Pine Research FSCV headstage adapters are available in different gains, as your research may require.  Contact Pine Research for pricing and lead time on a custom gain headstage amplifier.


Description

Pine Research currently offers working driven headstage amplifiers.  In a working driven system, the reference electrode is grounded.  The FSCV potential waveform (ramp) is connected to the non-inverting input of the operational amplifier, while the working electrode is connected to the inverting input.  In this arrangement, the voltage at the microelectrode will follow the ramp applied to the inverting input.1

Even when no electrodes are connected (connector just in air) to the headstage amplifier cable, which is connected to the WaveNeuro, HDCV will show a current response that follows the applied waveform.  As described below, this is expected.

In this two-electrode configuration, current arising from electron-transfer reactions, such as the oxidation of dopamine, passes between reference and working electrodes.  The measured current passes through the headstage amplifer, where it is converted to voltage, and sums with the the ramp voltage at the inverting input. Mathematically,

V_O=-(i_{in}times R_F)+V_R

where V_O is the output voltage, i_{in} is input current, R_F is feedback resistor (gain), and V_R is the CV ramp voltage.  By rearrangement, the signal voltage (proportional to the current across the 5: MOmega feedback resistor in the 200:nA/V headstage) is then

(V_R-V_O)=i_{in}times R_F=V_{signal}

HDCV software, which supports the WaveNeuro FSCV Potentiostat system, performs software subtraction of the ramp according to this relationship, resulting in only the true differential current measurement.1

(1) Takmakov, P.; McKinney, C. J.; Carelli, R. M.; Wightman, R. M. Instrumentation for Fast-Scan Cyclic Voltammetry Combined with Electrophysiology for Behavioral Experiments in Freely Moving Animals. Rev. Sci. Instrum. 2011, 82, 74302.

R.M. Wightman et. al. have reported on this topic in depth   If, after reviewing this document, you have any questions about our neuroelectrochemical research products, please do not hesitate to contact us.