[Comparative sensitivity of surviving sections of hippocampus to corticosteroids and angiotensin II]. / Sravnitel'naia chuvstvitel'nost' neironov perezhivaiushchikh srezov gippokampa k kortikosteroidam i angiotenzinu II.

Sensitivity of CA3 field neurones to hydrocortisone hemisuccinate, sodium dexamethasone-21-phosphate and angiotensin II was studied in experiments on surviving sections of the mouse hippocampus. High sensitivity of the neurones of surviving sections of the hippocampus to the steroid hormones (hydrocortisone and dexamethasone) and virtually complete absence of responses to angiotensin II were demonstrated.

[Reactions of an identified edible snail neuron to application of peptides, mediators, prostaglandins, and cyclic nucleotides]. / Reaktsii identifitsirovannogo neirona vinogradnoi ulitki na applikatsiiu peptidov, mediatorov, prostaglandinov i tsiklicheskikh nukleotidov.

Extracellular application of some peptides (oxytocin, Lys-vasopressin, Leu-enkephalin) to neuron RPal induced pacemaker potentials generation and initiated or increased bursting activity. Norepinephrine and prostaglandins E1 and E2 effects on neuron RPal electric activity were qualitatively similar to those produced by oxytocin and Lys-vasopressin. Dibutyryl-cAMP, papaverine (phosphodiesterase inhibitor) and sodium fluoride (nonspecific adenylate cyclase activator) induced or potentiated bursting activity. It is supposed that oxytocin, Lys-vasopressin, Leu-enkephalin, norepinephrine and E group prostaglandins effects are mediated by intracellular processes related to activation of adenylate cyclase and increase of cAMP level in the neuron.

[Bradykinin as a factor regulating synaptic inflow to the neurons in Helix pomata]. / Bradikinin kak faktor, reguliruiushchii sinapticheskii pritok k neironam Helix pomata.

The action of bradykinin on spontaneous electric activity of Helix pomata neurones from the subfaringeal complex was studied by microionophoresis. Bradykinin not only facilitates the neuronal responses to synaptic activation, but also prolongs the activation-induced generation of the potential action. Bradykinin effects were observed only in experiments conducted in spring.

[Direct action of angiotensin II on the central neurons]. / Priamoe deistvie angiotenzina II na tsentral'nye neirony

Reactions of the nervous cells in the somatosensory and visual regions of the brain cortex and the frontal hypothalamus in rabbits, as well as of the isolated nervous peripharyngeal ring of the Helix pomatia to the microionophoretic application of angiotensin II (A-II) was studied. Reactions of the neurons in the rabbit brain to A-II displayed an increase in the spike frequency depending on the quantity of the agent applied. Reactions of the frontal hypothalamus neurons showed a lower threshold than those of the brain cortex. A-II application to the some of the recorded cells of the mollusc evoked a marked reversible decrease in the membrane potential; as to the membrane resistance--it diminished 2--4 fold. These experimental data pointed to the direct A-II effect on the central neurons.