Kuznetsov Y. Influence of nootrops upon plastic qualities and hypoxic lesions of glutamatergic synapses of brain.

The dissertation contains the results of investigation in the mechanisms of influence and the character of influence of nootrop substances on long-term depression and depotentiation of synaptic transmission and hypoxic death of neurons and also the drawing out of the neuro-chemical mechanisms and factors which provoke these processes. It is established that nootrop substances (pyracetam, carbacetam, ethimizol, and glycin) simplify induction and expression of main forms of synaptic plasticity in hippocamp: long-term depression (juvenile rats) and depotentiation (mature rats) in CA1 region, but weaken the development of subsidiary forms of synaptic plasticity - long-term depression in gyrus dentatus of mature rats. It is demonstrated that different influence of nootrop substances is determined by the difference of neuro-chemical mechanisms of these forms of synaptic plasticity. Neuro-chemical mechanisms of early and delayed anoxic lesions of neurons are worked out and specified. It is determined that neuron-protective activity of nootropic substances of high concentrations, except glycin, simultaneousely with the procedure of anoxy/aglycaemy is caused by activation of NMDA receptors and highly threshhold potential-dependent Ca2+ channals ahd subsequent decrease in Ca2+release from intracellular depot. It is demonstrated that defensive activity of nootrops decreases immensely at delayed anoxic lesions and it is connected with their weak influence upon the processes of presynaptic liberation of glutamate, which are the basis of delayed anoxic lesions of neurons.