Hardware - data acquisition systems

Telemetry option

Video tracker

Stimulator

Audio amp

Digital I/O

Test generator

The dacq data acquisition system was originally designed for 'tetrode' (twisted quadruple electrode) recording and is therefore based around amplifier/filter modules and digital signal processor (DSP) cards providing 4 channels each (of which 16 can be accommodated, for a total of 64 channels). During recording, spike events trigger data capture on all 4 channels in a group. However, the triggering can also be configured to record signals on pairs of channels (stereotrodes) or single independent electrodes as required.

An optional video tracker can be synchronised with unit recording so that spike events can be correlated with position events. This is mainly useful for spatially-localised neural events such as place cell firing. A digital input module also allows unit recording to be coupled to other kinds of ongoing recording (such as lever-pressing).

An opto-isolated digital output board allows dacq to control experimental apparatus such as Skinner boxes.

Features:

• Preamplifier module with gain switchable between 100x (e.g. field potentials) and 1000x (e.g. single neurons); the preamplifier is normally located within 3 m of the experimental apparatus, but can be located up to 20 m away from the rest of the recording system

• 4-64 recording channels, arbitrarily electronically routable under software control between preamplifier and filter/amp modules for flexible reference channel selection (recording amplifiers may be configured as single-ended, or differential with respect to an abitrary reference channel)

• Filter/amp module with digitally programmable gain variable between 0.25x and 64x in 255 steps; in combination with the preamplifier (set to 1000x), this allows amplification between 250x and 64 000x in steps of 250x

• Digitally switched low- and high-pass filters (3 dB cutoff 500 Hz) and a switchable notch filter (tunable to 50 or 60 Hz)

• PC-hosted DSP card processes the digitised filter/amp module output to allow further digital filtering and spike separation, plus the potential for real-time cell clustering and other on-line analysis or control operations

64-channel recording system