[A comparative pharmacological study of the serotoninergic antidepressants tetrindole and fluoxetin]. / Sravnitel'noe farmakologicheskoe izuchenie serotoninergicheskikh antidepressantov tetrindola i fluoksetina.

Tetrindol, a selective inhibitor of MAOA (predominantly of serotonin oxidase) and fluoxetine, an inhibitor of serotonin neuronal uptake, were studied in psychotropic tests on mice and rats. Both drugs significantly intensified 5-hydroxytriptophan-induced head twitching, reduced the effect of reserpine and the destructive action of maximal electroshock and the scopalamine-induced transient disruption of memory in a test for conditioned response of passive avoidance in rats and mice. In a behavioral swimming test the drugs were less active. In potentiation of 5-HT activity both drugs were approximately equal.

[Role of various types of serotonin reception in the hypothalamic modulation of the release of luteinizing hormone]. / Rol'razlichnykh tipov serotoninovoi retseptsii v gipotalamicheskoi reguliatsii osvobozhdeniia liuteiniziruiushchego gormona.

Ciproheptadin was found to depress the activating effect of serotonin in the preoptic brain area and in the hypothalamic arquate nuclei. Blockade of the type II serotonin receptors increased the content of luteinizing hormone in the blood in dioestrus-2 stage and in the morning during pro-estrus. Microiontophoretic administration of serotonin into the thalamic arquate nuclei during the blockade decreased the luteinizing hormone level in the blood in dioestrus-2 stage and in the morning during pro-estrus. Administration of serotonin into the preoptic area under the same conditions invariably decreased the hormone level in the blood. A significant negative correlation was found between the luteinizing hormone contents in the blood and hypophysis.

Reaction of neurons of arcuate region of hypothalamus to microiontophoretic application of serotonin at different stages of the estrous cycle in rats.

Sensitivity to serotonin was investigated in single neurons of the arcuate region of the hypothalamus as the center of tonic regulation of gonadotropic function in conditions of its microiontophoretic application in different stages of the estrous cycle in rats. It was shown that at the diestrus-II stage of the estrous cycle, especially during morning hours, cells predominate among neurons of the arcuate region with activated reaction to serotonin. During proestrus increased representation of cells with inhibited reaction is noted among spontaneously functioning neurons, which is especially pronounced during evening hours of this stage of the cycle. Serotonin induced reduction in the level of luteinizing hormone in blood and this effect was usually combined with an activating effect of indolamine on functioning of neurons. The combination of a delayed effect of the neurotransmitter on spontaneous activity of neurons of the arcuate nucleus with a reduced level of luteinizing hormone in blood was noted in the overwhelming majority of cases only at the proestrus stage.

[Reaction of neurons in the arcuate hypothalamic area to the microiontophoretic application of serotonin at different stages of the estrous cycle in rats]. / Reaktsiia neironov arkuatnoi oblasti gipotalamusa na mikroionoforeticheskoe podvedenie serotonina v razlichnye stadii éstral'nogo tsikla u krys.

Among the neurons of the hypothalamic arcuate area, the center of tonic regulation of gonadotropic function, prevailed those with activating response to serotonin at the dioestrus-2 stage of the oestrus cycle, particularly in the morning hours. During prooestrus, an increased number of neurons with inhibitory responses was found, especially during evening hours. Serotonin induced a decrease in the amount of luteinizing hormone in the blood which was usually combined with an activating action of the indolamine on the neuronal activity. The combination of the neurotransmitter inhibitory effect on the spontaneous neuronal activity in the arcuate nucleus with the decrease of amount of the luteinizing hormone in the blood was mostly observed at the prooestrus stage only.