Responses of single units in the medial hypothalamus to electrical stimulation of the carotid sinus nerve in the cat

Thomas, Martin; Calaresu, F. R.

doi:10.1016/0006-8993(72)90365-4

Cited by 61 publications

(11 citation statements)

References 30 publications

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“…Thus the chemorecep tor afferent input is a potential arousing or alerting stimulus. This agrees with the reported activation of neurons in the medial hypothalamus on sinus nerve stimulation [presumably of chemoreceptor fibers (80)]. It also raises the question how artefactual may be studies on the pattern of cardiovascular response to chemoreceptor stimulation in animals anaesthe tized with traditional agents (chloralose, urethane, and barbiturates) that block or distort transmission through the hypothalamus and mid-brain.…”

Section: Effects Of Stimulation Of Peripheral Chemoreceptorssupporting

confidence: 81%

Central Nervous Regulation of Vascular Resistance

Hilton¹,

Spyer²

1980

Annu. Rev. Physiol.

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Section: Effects Of Stimulation Of Peripheral Chemoreceptorssupporting

confidence: 81%

Central Nervous Regulation of Vascular Resistance

Hilton¹,

Spyer²

1980

Annu. Rev. Physiol.

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“…nucleus of the solitary tract, ventro‐lateral medulla, nucleus ambiguous and dorsal vagal nucleus; Hannibal, 2002). In addition, the hypothalamus, which contains the highest concentrations of PACAP and PACAP‐specific receptors, has populations of neurones that (a) receive inputs from peripheral chemoreceptors (Thomas & Calaresu, 1972) (b) are sensitive to both CO 2 and O 2 (Waldrop & Porter, 1995) and (c) project directly to the phrenic motor nucleus (Kc et al 2002). Therefore, we consider it likely that PACAP acts centrally to modulate respiration.…”

Section: Discussionmentioning

confidence: 99%

Sudden neonatal death in PACAP‐deficient mice is associated with reduced respiratory chemoresponse and susceptibility to apnoea

Cummings

Pendlebury

Sherwood

et al. 2004

The Journal of Physiology

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Pituitary adenylate cyclase-activating polypeptide (PACAP)-deficient mice are more prone to sudden death during postnatal weeks 1-3 than wild-type littermates. Given that PACAP is localized in brainstem regions associated with respiratory chemosensitivity, we examined whether PACAP-null neonates have reduced respiratory responses to hypoxia and hypercapnia. Using unrestrained, whole-body, flow-through plethysmography we found that, by postnatal day 4, the PACAP-null neonates had significantly reduced ventilation during baseline breathing, and blunted responses to both hypoxia (10% O 2 -90% N 2 ) and hypercapnia (8% CO 2 -92% air). To determine whether the respiratory phenotype of the PACAP-null mice may contribute to their greater neonatal mortality, we used ECG to examine respiration and cardiovascular function of littermates. We demonstrate that, under conditions that exacerbate mortality of knockout but not wild-type animals, PACAP-deficient mice experience prolonged apnoeas that precede atrioventricular block. Both apnoeas and atrio-ventricular block were absent in wild-type littermates. These data suggest that PACAP-deficiency results in higher neonatal mortality primarily as a result of respiratory control defects and raise the possibility that mutations in genes encoding components of the PACAP signalling pathways may contribute to neonatal breathing disorders in humans.

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“…l " 4 Some investigators focused on responses of single units of the hypothalamus to stimulation of baroreceptor afferent input while others studied cardiovascular and plasma catecholamine responses to stimulation of different areas of the hypothalamus.…”

mentioning

confidence: 99%

Enhanced NE uptake by isolated hypothalamic storage vesicles of hypertensive rats.

Rho¹,

Newman²,

Alexander³

et al. 1983

Hypertension

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The in vitro uptake of 3 H-NE by storage vesicles from the hypothalamus of age-matched spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats has been studied using a new reliable procedure for the isolation of biochemically active storage vesicles. In each of 13 paired studies, done in triplicate, storage vesicles of SHR took up more 3 H-NE than those of WKY. (The mean difference was 37% more uptake by SHR.) Electron-microscopic examination of normotensive samples showed a concentration of intact synaptic vesicles; whereas SHR subfractions were composed of fragmented membranes that resembled swollen, distorted vesicles. These findings in the brain tissues of SHR parallel our previous results found in SHR peripheral tissues. Taken together, we interpret the results to indicate that the membranes of synaptic vesicles of SHR are altered structurally and biochemically. (Hypertension 5: 3-7, 1983) KEY WORDS • norepinephrine uptake • isolated hypothalamic storage vesicle spontaneously hypertensive rats N UMEROUS studies have implicated the hypo-thalamus with cardiovascular control mechanisms. l " 4 Some investigators focused on responses of single units of the hypothalamus to stimulation of baroreceptor afferent input while others studied cardiovascular and plasma catecholamine responses to stimulation of different areas of the hypothalamus. 2 ' 3-5-6 To investigate the role of the hypothalamus in hy-pertension, we elected to study the Okamoto strain of rats with spontaneous hypertension (SHR), since their hypertension is associated with elevated indices of sympathetic activity.'"* Hypothatamic lesions,** or separation of connections between hypothalamus and mesencephalon," cause a significantly greater decrease of blood pressure in SHR than in Wistar-Kyoto (WKY) control rats. Conversely, electrical stimulation of the posterior hypothalamus 12 l3 elicits greater blood pressure increases in the SHR than in control WKY. Furthermore, SHR show changes in hypothalamic catecholamine metabolism in those areas which affect blood pressure. Thus, Nagaoka and Lovenberg 14 reported that during the early development of hyper-tension in the SHR, the activities of both tyrosine hy-droxylase and dopamine-B-hydroxylase (DBH) in the hypothalamus were significantly higher than in the control WKY rats. Nevertheless, a lower NE content in the hypothalamus of SHR was reported as early as 1970 by Yamori et al. 15 and recently by Saavedra et al. 9 andTsobe et al. TS The concentration of epinephrine was elevated in the hypothalamus of SHR as reported by Gianutsos and Moore. 17 Other approaches to studies of the hypothalamus in SHR have focused on adrenocep-tor activity and, at present, the findings are conflicting .'*-20 We recently reported results of in vitro 3 H-NE uptake by peripheral tissues in SHR and WKY. 21-n In the present study, we examined the in vitro uptake of 3 H-NE by isolated hypothalamic storage vesicles from age-matched SHR and WKY rats. Results show that the Mg 2+-activated ATPase dependent amine uptake of SHR h...

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Responses of single units in the medial hypothalamus to electrical stimulation of the carotid sinus nerve in the cat

Cited by 61 publications

References 30 publications

Central Nervous Regulation of Vascular Resistance

Central Nervous Regulation of Vascular Resistance

Sudden neonatal death in PACAP‐deficient mice is associated with reduced respiratory chemoresponse and susceptibility to apnoea

Enhanced NE uptake by isolated hypothalamic storage vesicles of hypertensive rats.

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