Multi-channel cable assembly for long-lasting recording and/or stimulation of brain electrical activity in small laboratory animals.

A low cost multi-channel (8 single ended or 4 differential) recording and/or stimulating cable assembly is described. The assembly is shown to be suited for derivation of slow and fast brain electrical activity in small laboratory animals confined to an experimental cage. A light-weight impendance transforming circuit (ITC) at the input stage minimizes the movement artifacts associated with the use of the high impedance electrodes. The easy rotating pressurized air-operated commutator equipped with gold-gold slip ring contacts makes the assembly suited for 24 hr recordings and/or stimulation of brain electrical activity. The number of the channels in the assembly can be increased readily with little increase in the weight of the ITC and in the inertia of the commutator.