Osmosensitive single neurones in the hypothalamus of unanaesthetized monkeys.
James N. Hayward,Jean D. Vincent +1 more
TLDR
This work recorded with tungsten micro‐electrodes the activity of single neurones in the supraoptic nucleus (NSO) and adjacent regions of the hypothalamus while repeatedly injecting solutions of varying tonicity into the common carotid artery of trained, unanaesthetized monkeys who accepted the experimental restraints without anxiety.Abstract:
1. We recorded with tungsten micro-electrodes the activity of single neurones in the supraoptic nucleus (NSO) and adjacent regions of the hypothalamus while repeatedly injecting solutions of varying tonicity into the common carotid artery of trained, unanaesthetized monkeys who accepted the experimental restraints without anxiety.
2. Intracarotid injections of mildly hypertonic solutions of sodium chloride produced a characteristic behavioural response during and immediately after injection: e.e.g. ‘arousal,’ lip and tongue smacking, chewing, irregular sniffing respiration and associated mildly increased movement of face, eyes and body.
3. Of the 130 cells analysed during hypertonic intracarotid injections, 105 (81%) were osmosensitive. Twenty-five (19%) of the cells studied during similar injections were non-osmosensitive. On the basis of the anatomical location of the cells, the pattern of discharge to intracarotid osmotic stimuli and the response to arousing sensory stimuli, we divided the osmosensitive cells into two major groups, ‘specific’ and ‘non-specific’ osmosensitive cells.
4. Fifty-two (50%) of the osmosensitive cells we labelled ‘specific’ because they responded to an intracarotid injection of hypertonic sodium chloride, generally did not respond to non-noxious arousing sensory stimuli and were located in or near the supraoptic nucleus. We found two subtypes of these ‘specific’ osmosensitive cells: (a) twenty-one (20%) NSO cells with ‘biphasic’ responses, that is, acceleration followed by inhibition; (b) thirty-one (30%) cells in the immediate perinuclear zone of the NSO with ‘monophasic’ responses, subdivided into twenty-one (20%) cells that accelerated and ten (10%) that were inhibited.
5. Fifty-three osmosensitive cells (50%), located diffusely in the anterolateral hypothalamus, were ‘non-specific’, responding both to intracarotid injections of hypertonic sodium chloride and also to sensory stimuli that were mildly arousing. Two groups of ‘non-specific’ osmosensitive cells showed monophasic responses; thirty-five (34%) cells accelerated and seventeen (16%) of them were inhibited.
6. The ‘monophasic’ specific osmosensitive neurones lying in the immediate perinuclear zone of the supraoptic nucleus in the primate could conceivably be the ‘osmoreceptors’ of Verney. The ‘biphasic’ specific osmosensitive neurones in the NSO may well represent the secretory cells of this system. From our data, the ‘non-specific’ osmosensitive neurones, scattered diffusely in the anterolateral hypothalamus, have little to do with osmoregulation. Some of these cells located in the perinuclear zone of the NSO could act as interneurones, however, conveying afferent input to the osmoreceptor-secretory complex of the supraoptic nucleus.read more
Citations
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Journal ArticleDOI
Electrophysiology of hypothalamic magnocellular neurones secreting oxytocin and vasopressin
TL;DR: The hypothesis that nerve cells are true secreting cells, and act upon one other and upon the cells of other organs by the passage of a chemical substance of the nature of a ferment or proferment from the first cell to the second is formed.
Book ChapterDOI
The regulation of vasopressin function in health and disease.
TL;DR: The osmoregulation of AVP can be readily understood by analyzing the relationship between plasma AVP and plasma osmolality under different conditions of water balance.
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Electrophysiological differentiation of oxytocin-and vasopressin-secreting neurones
TL;DR: It is suggested that the rate of vasopressin secretion into the circulation largely depends on the proportion of vasipressin neurones firing phasically, their firing rates within the phases and the duration and degree of synchronization of the phases.
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Comparison of firing patterns in oxytocin- and vasopressin-releasing neurones during progressive dehydration
TL;DR: Both vasopressin and oxytocin neurones are activated during chronic dehydration, but there is a marked difference in the pattern of their response, which is important in increasing the occurrence of short interspike intervals and thus facilitating hormone release.
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Morphological and electrophysiological classification of hypothalamic supraoptic neurons
TL;DR: The firing patterns of activated OT and VP neurons often differ, but can transiently appear indistinguishable in vivo and especially in vitro, and classification in vitro without immunochemical labelling may be aided by the presence of phasic bursting and by the differential response of these neurons to certain neurochemicals or to stimulation of certain inputs.
References
More filters
Journal ArticleDOI
Effects of progesterone and sensory stimulation on EEG and neuronal activity in the rat
TL;DR: Progesterone in this preparation is considered to exert differential effects on neurons through a nonspecific depression of arousal, since the activity of individual neurons is bound more or less closely to the arousal level.
Journal ArticleDOI
Changes in electrical activity of the medulla on the intravenous injection of hypertonic solutions.
TL;DR: Electric recording with insulated steel electrodes in the dorsal part of the medulla of the cat has revealed an area which responds to changes in the tonicity of the blood stream, which may represent a central site of osmoreception.
Journal ArticleDOI
Reactions of neurons in or near the supraoptic nuclei.
TL;DR: The reactions of neurons within or near the supraoptic nuclei of the hypothalamus to a variety of "stimuli" were studied and some neurons were affected by several of the stimuli employed but the majority of neurons were unresponsive during the periods of recording which could be maintained.
Journal ArticleDOI
Diuretic and thermoregulatory responses to preoptic cooling in the monkey
JN Hayward,MA Baker +1 more
Journal ArticleDOI
Influence of limbic system on neurohypophysis.
James N. Hayward,Wilbur K. Smith +1 more
TL;DR: The rate of release of the antidiuretic hormone from the neurohypophysis into the hypophysial veins depends upon various factors, among which are osmotic pressure, blood volume, body temperature, and the emotional state.
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