A miniature multichannel preamplifier for recording electrophysiological activity in freely moving animals.

A design for a miniature preamplifier for recording electrophysiological activity in freely moving small animals is proposed. The preamplifier is relatively simple to make and use and allows differential recording of neuron activity, EEG, and evoked potentials in multiple channels. When necessary the preamplifier can easily be disassembled for repair. A thin, flexible cable and a "gentle" suspension system prevent interference with the animal's free movement. The design is light in weight and allows electrophysiological activity to be recorded in mice even while they are swimming in a Morris tank.