Effects of strabismus and monocular deprivation on the eye preference of neurons in the visual claustrum of the cat.

Visual response properties of neurons in the dorsocaudal claustrum were studied in two cats reared with convergent strabismus and three cats reared with monocular lid-suture. In the normal claustrum, most cells respond about equally well to stimulation of either eye (Sherk and LeVay, '81). In the strabismic animals, there was a partial breakdown of binocularity: most cells remained binocular but were influenced more strongly by one eye (usually the contralateral eye) than the other. The loss of binocularity was less extreme in the claustrum than in area 17 of the same animals. In the monocularly deprived cats, claustral cells responded exclusively to the experienced eye. We interpret the changes observed in the claustrum as reflecting changes in the ocular dominance of cortical inputs to the claustrum, rather than as evidence for plasticity within the claustrum itself. Autoradiography was used to study the return projection from claustrum to cortex in monocular deprivation. The cortical labeling pattern resembled that seen in normal cats. To examine whether this return projection might be involved in reducing cortical responsiveness to the deprived eye, recordings were made from area 17 of a monocularly deprived cat before and after ablation of the ipsilateral claustrum by injection of kainic acid. Following ablation, there was no unmasking of cortical responses to the deprived eye. Thus the cortico-claustral loop does not appear to suppress cortical responses to the deprived eye.