Showing papers on "Solitary tract published in 1977"
TL;DR: Two distinct hypnogenic structures have been documented in the cat: the nucleus of the solitary tract in the medulla and a region in the basal preoptic area, which can be activated and inhibited in relation to circulatory or thermic homeostasis and to endocrine regulations.
Abstract: Active cerebral processes can initiate and maintain sleep in mammals. Two distinct hypnogenic structures have been documented in the cat: the nucleus of the solitary tract in the medulla and a region in the basal preoptic area. Their electrical or pharmacological activation results in behavioral and EEG sleep. Both can be activated and inhibited in relation to circulatory or thermic homeostasis and to endocrine regulations, or in conditioned paradigms. Bilateral destruction or functional elimination of either hypnogenic region is followed by increased vigilance and insomnia. The tonic influence so revealed is increased by the serotonergic raphe nuclei of the pontine region, which is considered to be hypnotonic rather than hypnogenic. Postsynaptic inhibition of the ascending activating reticular system by the hypnogenic centers is involved in sleep onset and maintenance. Electrophysiological evidence is presented that indicates a mutual tonic inhibitory interaction between the brainstem arousal system and the preoptic hypnogenic center. Such reciprocal inhibitory interaction can facilitate the onset of sleep by a positive‐feedback mechanism. In spite of the fact that this retroaction results in break of physiological equilibrium, it should be considered a homeostatic process aimed at maintaining the functional fitness of the forebrain neuronal circuits. Copyright © 1977 American Neurological Association
60 citations
TL;DR: In anaesthetized, spontaneously breathing cats and dogs, extracellular recordings were made of the spontaneous activities of 28 single neurones with cardiac rhythm, it was confirmed by histological examination that the neurones were situated in the mediodorsal portion of the nucleus of the solitary tract.
34 citations
TL;DR: It is suggested that clonidine causes bradycardia but not hypotension as a result of a long-lasting central activation of baroreceptors.
26 citations
TL;DR: In anaesthetized, spontaneously breathing cats and dogs extracellular recordings were made of the spontaneous activities of 28 single neurones with cardiac rhythm, it was shown by adequate stimulation and elimination of the vagus nerves that the neurones of group c were influenced by lung inflation receptors as well as by cardiovascular receptors.
23 citations
TL;DR: In these experiments LSD and 5-hydroxytryptamine appeared to act additively in that alerting and electrocortical desynchronisation was usually the eventual consequence of the sequential perfusion of these substances.
17 citations
TL;DR: The results suggest that acetylcholine is involved in the neurotransmission process in the region of the supraoptic nucleus and that cells located there may play a role in regulating gastric secretion and salivation.
8 citations
TL;DR: It was concluded that the nucleus of solitary tract is an essential part of the central pathway of the J reflex and was abolished by bilateral lesions in the NTS.
Abstract: Experiments were carried out on cats anaesthetized with chloralose-urethane with a view to defining certain central pathways for the J reflex elicited by the right atrial injection of phenyldiguanide. The resulting motor inhibition was manifested by reduction in the amplitude of the knee jerk. The dorsal surface of the medulla was exposed and free riding platinum quartz electrodes were introduced into the nucleus of solitary tract. Lesions were made in the NTS by passing current of know intensity through the electrodes.
6 citations