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The intranasal administration of glutamate antibodies in the dose of 300 microg/kg one hour after damage on the level of mRNA expression of Dffb gene which codes caspase-activated DNase which participates in intranucleosome fragmentation of genome DNA in apoptosis was investigated in experimental Alzheimer's disease induced by injection of neurotoxic fragment of beta-amyloid protein Abeta25-35 in Meynert basal magnocellular nuclei on rats. On the Day 3 after Abeta25-35 injection is observed significant decrease of the level of mRNA expression of Dffb gene in prefrontal cortex in 37%, and in hippocampus in 62% in the experiment group versus the control group. These differences were not found in the hypothalamus when comparing the experimental and control animals. It was suggested that repressive effect of glutamate antibodies on the level of mRNA expression of Dffb gene reflects stabilization of processes taking place in brain cells in experimental Alzheimer's disease, and in its turn the intensiveness of nerve and glial cells apoptotic death is decreased.

Electron microscopic investigation indicates that in T. graeca the optic nerve consists of about 216,000 fibers of which 11% are myelinated and 89%--unmyelinated ones. The diameter of myelinated fibers varies within 0.2-2.5 mu, the main bulk of fibers (42%) having the diameter 0.5-0.7 mu. The diameter of unmyelinated fibers varies between 0.1 and 0.35 mu. With respect to their diameter, 8% of the fibers of both groups overlap each other. During electrical stimulation of the optic nerve, action potential in the latter is recorded which consists of two high amplitude components. The first component (propagation velocity 1.5 m/sec) presumably corresponds to conduction of excitation along myelinated fibers, the second one (propagation velocity 0.6 m/sec)--along unmyelinated fibers.

Studies have been made on.morpho-functional changes in the optic nerve and midbrain tectum after enucleation of the tortoise T. horsfieldi. It was found that intensive degeneration of terminals which follows "dark" type (3--31/2 months after enucleation) corresponds to degeneration of myelinated fibers. Terminals degenerating accordingly to "light" type (2--3 months) presumably belong to unmyelinated fibers, which degenerate at this period in the nerve. Terminals which follow "vesicular" degeneration, survive up to 6--61/2 months, probably due to survival of some unmyelinated fibers in the nerve. During degeneration of the optic fibers, corresponding changes in amplitude-temporal parameters of the evoked potentials in the midbrain tectum were observed during electrical stimulation of the optic nerve. These changes include the increase of the interval between the stimulus and the peak of both components, as well as the decrease of the amplitude of the responses. These changes were originally observed 11/2--2 months after enucleation, becoming more evident at later stages; 6--61/2 months after enucleation, both components of the evoked potential disappeared almost simultaneously.

Electrophysiological and electron microscopic studies have been made on degeneration in the optic nerve and midbrain tectum after enucleation of the tortoise T. graeca. It was found that intensive degeneration of terminals which follows "dark" type (1/2--1 month after enucleation) corresponds to degeneration of myelinated fibers. Mass degeneration of the "light" type is associated with degeneration of unmyelinated fibers, being observed 1 1/2--2 months after the enucleation. The main bulk of fibers and terminals degenerates at the period of 4--4 1/2 months. Changes in functional characteristics of the evoked potentials (EP) follow morphological ones and consist in an increase of the interval between the stimulus and the peak of EP components, as well as of the decrease of the amplitude of the EP. Within 4--4 1/2 months, both EP components disappear almost simultaneously.

The optic nerve of the tortoise Agrionemys horsfieldi contains about 400,000 fibers (90% unmyelinated and 10% myelinated ones). the diameter of unmyelinated fibers varies from 0.3 to 1.1 mu, mean value being equal to 0.5 mu; fibers with a diameter 0.4-0.7 comprise 77%. The diameter of myelinated fibers varies within 0.3-3.0 mu, average value being 0.5-0.8 nu; fibers with a diameter 0.5-0.9 mu amount to 62%. Electrogram of the optic nerve consists of two components which are equal in their amplitudes. These components presumably reflect summary firings of modal groups of unmyelinated and myelinated fibers. The velocity of propagation of excitation along the fibers producing the first component is equal to 1.3 m/sec, wheras that in fibers producing the second component - to 0.5 m/sec. The data obtained are compared with those related for the other tortoise - Emys orbicularis.