[Perturbations of the vesicle cycle in reticulospinal synapses of axons in lamprey after presynaptic microinjections of GTPgammaS].

The synaptic vesicle cycle sustains neurotransmission and keeps pace between exo- and endocytosis in synapses. GTP-binding proteins function as key regulators of this cycle. The large GTPase dynamin is implicated in fission of clathrin-coated vesicles from the presynaptic membrane during endocytosis.

[Changes in the ultrastructure of the motor zone of the cortex and various areas of the rats pyramidal system in acute toxic action of phenazepam].

As it was revealed by electron microscopic study, phenazepam (benzodiazepine representative) administered to rats in acute toxic dose caused astrocyte processes swelling mainly in reticular portion of substantia nigra and cerebral areas with high density of GABAergic synapses in initial intoxication stage (one hour after the drug introduction). Following 24 hrs changes of axodendritic and axo-somatic synapse postsynaptic part were detected similar to those of myoneural synapses induced by anti-cholinesterase agents, which allows to suggest the contribution of the increased intracellular calcium ions content. Specific benzodiazepine receptor agonist-flumazenil, introduced 30 min later than phenazepam leaded to the decrease of ultrastructural changes in postsynaptic part of the synapses in reticular zone of substantia nigra.

[Initial ultrastructural changes in the muscle fibers of the diaphragm in rats exposed to chlorophos].

Ultrastructural changes of rat diaphragm muscle fibers were studied after administration of chlorophos, i. e. organophosphorus inhibitor.