Postnatal development of the synaptic organisation of the lateral geniculate nucleus in the kitten with unilateral eyelid closure.

Abstract

CLOSURE of the eyelids over one eye during a well defined period of susceptibility in kittens has been shown to result in severe structural changes of the nerve cells in the lateral geniculate nucleus1,2. Neurones in those parts of the lateral geniculate nucleus which are related to the binocular visual field and which receive fibres from the closed eye are smaller than those in the laminae innervated from the open eye. The fact that cellular changes do not occur in the part of the nucleus related to the monocular visual field has led to the hypothesis that there is a process of competition or an imbalance between the neurones in the deprived and stimulated portions of the binocular parts of the laminae, whereas such competition is not present in the monocular segment2,3. We have examined the lateral geniculate nucleus with the electron microscope at different intervals extending through the period of susceptibility after monocular eyelid closure and in a parallel series of normally reared kittens.