0000000000790246
AUTHOR
St. Reuss
Electrophysiological investigations on the central innervation of the rat and guinea-pig pineal gland
The possible influence of central nervous structures on the electrical activity of single pineal cells was investigated in rat and guinea-pig. In the rat electrical stimulation of the hippocampal formation elicited both single cell responses with different latencies and mostly long-term excitations in single pineal cells, while stimulation of the habenular nuclei caused clear orthodromical responses with different latencies, alterations in the rate of spontaneous electrical activity and evoked discharges of "silent" units. In the guinea-pig electrical stimulation of the paraventricular nucleus influenced predominantly cells in the deeper layers of the posterior part of the pineal gland. Ele…
Chemical sympathectomy and clorgyline-induced stimulation of rat pineal melatonin synthesis
The response to administration of the specific monoamine oxidase A (MAO-A) blocker clorgyline was investigated in adult male Sprague-Dawley rats which were sympathectomized by injection of the false neurotransmitter 6-hydroxydopamine as newborns. In intact animals which served as controls, the contents of pineal indoles melatonin, serotonin, 5-hydroxytryptophan were augmented, and the content of 5-hydroxyindoleacetic acid decreased 90 min following clorgyline injections when compared to saline receiving rats. Sympathectomized animals exhibited similar responses but these were less pronounced. It is suggested that blocking of the oxidation of both MAO-A substrates, noradrenaline and serotoni…
Clorgyline effect on pineal melatonin biosynthesis in adrenalectomized rats pretreated with 6-hydroxydopamine
The response to administration of the specific monoamine oxidase A (MAO-A) blocker clorgyline was investigated in adult male Sprague-Dawley rats which were adrenalectomized four days prior to treatment or were additionally sympathectomized as newborns by injection of 6-hydroxydopamine. In both groups, the contents of pineal indoles melatonin and N-acetylserotonin were augmented, and the contents of 5-hydroxyindoleacetic acid and 5-hydroxyindoletryptophol decreased 90 min following clorgyline injections when compared to rats receiving saline. The observed responses were less pronounced in rats both adrenalectomized and sympathectomized. The results are in line with the hypothesis that preser…