[Brain development and the environment].
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Animals↗
Biomedical subjects
A A Volokhov
Publications and source records attributed to A A Volokhov.
[Neurophysiologic and biochemical aspects of visual system development in the rabbit under conditions of photic deprivation].
Changes in the functional state of the visual cortex were studied by behavioral and electrophysiological cues and the chemism of its neurones at the cellular and subcellular levels in rabbits raised for one to two months in the dark. It has been shown that visual deprivation leads to retarded dynamics of elaboration and consolidation of the conditioned defensive reflex to light and to changes of opposite signs of the visual cortex surface EPs to specific and non-specific stimuli. Typical of the EPs to photic stimuli is a considerable decrease in amplitude and longer latency as compared with normal, and enhanced amplitude and shorter latency to acoustic stimuli. It has been cytochemically established that about half of the pyramidal neurones of the visual cortex layer V of the experimental animals display features of biochemical underdevelopment (of the size of the cytoplasmatic mass, the protein reserve). Under the same conditions activity depression was revealed in cytochromoxydase, Na, P-ATPhase and ACHE, expressed to a different degree in separate subcellular fractions of the visual cortex. The MAO activity selectively augments in the subfraction of cholinergic synaptosomes. It has been assumed that functional and biochemical changes in different groups of the visual cortex neurones due to deprivation are linked with both the properties of the synaptic structures in regard to perception of impulses of different modalities and the peculiarities of their chemism.
Animals↗
[Effect of early motor training on evoked potentials of rat brain visual and sensomotor cortex].
Motor training (during 3-6 months) of rats in a treadmill started at the age of 1 month, leads to statistically significant increase in the activity of neuronal populations in the visual cortex judged by both latencies of primary responses and recovery cycles of responses to paired stimuli. It has been found that the significance of functional changes following locomotor training is more manifest in the recovery cycles than in the latencies of primary responses. The comparison of locomotor training effects in the visual cortex with those in the sensorimotor cortex reveals a more pronounced modulating influence of environment on the visual cortex. However the differences in these functional changes are more evident by absolute (msec) than by relative (%) cues.
Animals↗