QUANTITATIVE MORPHOMETRIC STUDY OF THE IN FLUENCE OF A PARTIAL VISUALDEPRIVATION ON THE DEVELOPMENT OF 2 TYPES OF NEURONS IN THE VISUAL WULST OF PIED FLYCATCHER NESTLINGS

Neurons of the Wulst area (analogous to mammalian visual cortex) were studied with the method of computerized morphometry (6 parameters) in frontal Golgi-stained sections of pied flycatcher nestlings which were binocularly deprived since the age of 1-1.5 days post-hatching. The c urrent study was focused on two types of neurons: spiny stellate and s mall spineless stellate-like cells. It was found that the visual depri vation not only slowed down the morphogenesis of these neurons but als o caused the constructive changes - increase in the number of foci of maximal dendrite branching - in spiny stellate neurons which we had ea rlier defined as projective cells. Changes in small spineless stellate -like neurons (earlier defined as intercalate cells) were of, mostly, opposite direction. In the latter neurons we observed a reduction of t he number of dendrites and dendrite branches, Opposite changes in diff erent cell groups caused by the limitation of sensory input may, on th e one hand, point to a difference in functional connections of ascendi ng afferent fibers with different types of neurons, and, on the other hand, indicate a different degree of the influence of visual experienc e on the development of these neurons.