Extracellular spike recording
Electric current flows in the nerve tissue around the neurons during action potentials and it can be detected by means of extracellular microelectrodes as extracellular ‘spikes’. The greatest advantage of extracellular recording is that the activity of neurons can be recorded without having to impale and consequently damage them.
Signals picked up by extracellular electrodes need to be amplified to be able to be processed in more conventional electronic devices such as oscilloscopes, analyzers or computers. The microelectrode must be connected to a specialized preamplifier (also known as a headstage probe) in order to work properly. The electrical properties (mainly the signal-to-noise ratio) of the microelectrode, headstage and main amplifiers set a limit to the smallness of signals that can be reliably measured.
ExAmp-20K spike amplifier kit
Main amplifier unit
The ExAmp-20K is an AC-coupled spike amplifier designed for low-noise extracellular recording from single- or multiple units in single-ended (monopolar) mode. The built-in filters (300 Hz to 8000 Hz, bandpass) are optimized for spike recordings. The included 50/60 Hz reject (notch) filter and our special electrode holder adapters virtually eliminate the need for Faraday cages. Requires a 12 VDC external power supply, order separately. See our international model M1116.
Kit is sold complete with main unit, headstage probe, 2 mini banana plugs, 5 gold-plated pins mating with headstage probe’s grounding socket and a manual.
The M2111 headstage probe
The greatest power of our extracellular recording system relies in the unique headstage probe which is an electrode holder in one. Using one of our holder adapters, the microelectrode can actually be plugged into the probe minimizing the length to the extreme between the electrode and the first stage of amplification allowing an ultra-low noise recording.
It has a nickel-plated brass body containing the first stage of amplification mounted on a 1/4" diameter (6.4 mm) cable-holding tube which can be used to fix the probe in many micromanipulators. We also offer adapters with three mounting hole sizes for conveniently attaching the probe’s body to stereotactic micro drives. For details, see our SA1525-X adapters.
Microelectrode holder adapters need to be ordered separately.