Krysanova N. Uptake and release of glutamate in rat brain nerve terminals under conditions of altered gravity.

Object - glutamate transport systems in isolated rat brain nerve terminals. Aim - the study of key presynaptic processes underlying glutamatergic neurotransmission under conditions of altered gravity. Methods: preparative biochemistry, photon correlation spectroscopy, flow cytometry, spectrometry, radioisotope techniques. Structural (size and granularity) and functional (membrane potential and acidification of synaptic vesicles) characteristics of brain nerve terminals of control rats and rats subjected to hypergravity loading in cranio-caudal direction were analyzed comparatively. Under hypergravity conditions, we demonstrated the changes in stimulated by depolarization exocytotic glutamate release, Na+-dependent glutamate uptake and release of glutamate from cytosolic pool of nerve terminals. It was concluded that the redistribution of the neuromediator between vesicular and cytosolic pools took place under hypergravity conditions, also, glutamate transporter reversal was increased, which is an indicator of hypoxic injury of neurons. Taken together, the experimental data allow to conclude that the changes in glutamaergic neurotransmission are the background for the development of neurological symptoms under conditions of altered hypergravity. Scope - organizations of medical and biological profile.