The differential effects of unilateral lid closure upon the monocular and binocular segments of the dorsal lateral geniculate nucleus in the cat

Abstract

One eyelid has been sutured in each of three seven-day old kittens.Three months later the brains were fixed and stained by the Nissl method. In the contralateral lateral geniculate nucleus the cells of the deprived lamina A were smaller, more closely packed and paler staining than those i n the normally innervated, ipsilateral lamina A. However, these changes were seen in the medial parts of the contralateral lamina A only. The lateral parts, which extend beyond the border of lamina A1 and which project to the monocular parts of the visual cortex showed no change.These results show that some geniculate cells are not affected by deprivation. The observations are consistent with the view that during normal development geniculate cell axons from adjacent laminae compete with each other for synaptic surfaces upon binocular cortical neurons: that unilateral lid suture upsets the balance of this competition and that the reduced perikaryal growth in the lateral geniculate nucleus is secondary to the unbalanced axonal development, which occurs in the binocular portions of the geniculocortical projection but which cannot occur in the monocular portions, where there is no competition.

Postnatal development of the visual cortex and the influence of environment

“…One reason for this is that their shrunken cortical arbors may require a smaller soma to maintain them, as originally proposed by Guillery and Stelzner (1970). 26 Morphological examination of the lateral geniculate nucleus in these animals showed that there is a good relationship (r = 0.91) between the relative size of normal and deprived cells and the relative size of normal and deprived ocular dominance columns in layer IVC. 15 Thus, measuring geniculate cell sizes is yet another means of evaluating the effects of monocular closure.…”

“…26,45,46 First it was demonstrated in monocularly occluded kittens that deprived cells in the monocular segment of the nucleus were of normal size, whereas those in the binocular segment showed marked shrinkage. 26 Next Guillery produced a monocular region in the zone of binocular overlap by making a local retinal lesion in the normal eye of monocularly occluded kittens. 45 Again the deprived geniculate cells with no competitive input from the other eye were of normal size, and those outside the topographical area corresponding to the retinal lesion showed the usual shrinkage.…”

The development of potentially better practices to support the neurodevelopment of infants in the NICU

“…98,99 There is also shrinkage in the size of the LGN on the affected side and compensatory increase in the contralateral LGN. 100 How is this plasticity affected by sleep? As noted, the endogenous phasic neuronal activity necessary for brain wiring of the developing visual system occurs during REM sleep.…”

Topography of Auditory Nerve Projections to the Cochlear Nucleus in Cats after Neonatal Deafness and Electrical Stimulation by a Cochlear Implant

“…Such topographic maps comprise one of the fundamental organizing features of the central nervous system, and over the past few decades, there has been a major focus in developmental neurobiology on examining changes in the specificity of these maps during development and in defining the specific roles of afferent input and molecular cues in the formation and maintenance of precise topographic connections (see Rubel and Cramer 2002 for review). In the visual system, earlier studies of development emphasized that competition driven by activity is essential for refinement of initial broad or diffuse neuronal projections into more precise adult patterns (e.g., Guillery and Stelzner 1970;Shatz 1990;Goodman and Shatz 1993). Spontaneous waves of correlated rhythmic neural activity in retinal ganglion cells occur for some time before the onset of vision and are thought to be essential for the normal development of precise topographic maps at all levels of the visual system (Cang et al 2005;Constantine-Paton et al 1990;Maffei and Galli-Resta 1990;Shatz 1990Goodman and Shatz 1993;Feller et al 1996;McLaughlin et al 2003b;O'Leary and McLaughlin 2005).…”