Phasic discharge in supraoptic neurones recorded from hypothalamic slices

Haller, Edwin W.; Brimble, M. J.; Wakerley, J. B.

doi:10.1007/bf00238799

Cited by 28 publications

(12 citation statements)

References 8 publications

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“…We think that the reduced spontaneous activity in the partly or totally isolated hypothalamus was due to a reduced excitatory input. The results of Hatton, Armstrong & Gregory (1978) and Haller, Brimble & Wakerley (1978) which showed a reduced activity ofcells in the supraoptic nucleus in hypothalamic slice preparations in vitro support this suggestion. The possibility remains, however, that the cuts exposed the neurones of the supraoptic nucleus to a previously masked inhibitory input from another site within the island, for example the septum (Poulain, Ellendorff & Vincent, 1980).…”

Section: Discussionsupporting

confidence: 62%

Responses of supraoptic neurones in the intact and deafferented rat hypothalamus to injections of hypertonic sodium chloride.

Dyball¹,

Prilusky²

1981

The Journal of Physiology

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SUMMARY1. Recordings were made from a total of fifty-three neurones in the supraoptic nuclei of four groups of rats: intact rats, animals in which the hypothalamus had been partly denervated by anteriorly or posteriorly placed semicircular cuts, and rats with a totally deafferented hypothalamus. 4. The results imply that under the conditions ofthese experiments the spontaneous activity of the supraoptic nucleus in intact animals was maintained by an extrahypothalamic excitatory input, that partial hypothalamic isolation reduced its intensity, possibly by unmasking an inhibitory input, and that total isolation reduced it to an even greater extent. Osmotic activation of supraoptic cells was only possible when the anterior connexions of the hypothalamus were intact. Thus the cerebral osmoreceptors for vasopressin release may be situated outside the supraoptic nuclei.

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Section: Discussionsupporting

confidence: 62%

Responses of supraoptic neurones in the intact and deafferented rat hypothalamus to injections of hypertonic sodium chloride.

Dyball¹,

Prilusky²

1981

The Journal of Physiology

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“…Thus we subjected neurosecretory units recorded from the hypothalamus to chemical as well as osmotic stimulation, so that we could examine the resultant firing patterns. Preliminary accounts of some of these results have already been published (Brimble, Haller & Wakerley, 1978b;Haller, Brimble & Wakerley, 1978).…”

Section: One Hundred and Two Pv And So Units Incubated In Hypertomentioning

confidence: 97%

Electrophysiological studies of paraventricular and supraoptic neurones recorded in vitro from slices of rat hypothalamus.

Haller¹,

Wakerley²

1980

The Journal of Physiology

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SUMMARY1. In slices (300 stm) of rat hypothalamus maintained in vitro in isotonic (298 + 4 m-osmol/kg) medium, the median firing rate of twenty-four supraoptic (s.o.) neurones was 0.05 spikes/s, compared to 0-66 spikes/s for twenty-eight paraventricular (p.v.) 4. Mean durations of bursts and silent periods in phasic cells excited by perifused glutamate were 16-6 s and 13-2 s (calculated from normalized distributions of thirty values), compared to means of 41-7 s and 33-9 s (thirty-six values, P < 0-001 for each parameter) for cells excited by glutamate ionophoresis. The periodicity of phasic firing in vitro was unaffected by a change to hypertonic (340 m-osmol/kg) medium.5. From these in vitro results it is proposed that the excitation associated with osmotic stimuli in vivo does not originate within the p.v. and s.o. neurosecretory cells, but that it involves a separate osmoreceptor. However, the control of phasic firing, which is commonly found during osmotic excitation, would seem to involve a mechanism which lies within or in close proximity to, the neurosecretory neurones.

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“…This article must therefore be hereby marked "ad- KH2PO4, 0.4; CaCl2, 0.75; MgCl2, 0.5; MgSO4, 0.4; glucose,11; phenol red, 0.03; Hepes,10) and their upper surfaces were exposed to warmed, humidified oxygen. After a period of 1 hr, the level of the medium was raised above the surface of the slices, and oxygenated, warmed (35-370C) solution was perfused through the chamber at 1.5 ml/min.…”

mentioning

confidence: 99%

“…Therefore, one might expect opiateinduced alterations in neurohypophysial secretion to be reflected in changes in the electrical activity of these neurons. We have looked for such effects, using the in vitro hypothalamic slice preparation, which demonstrates neuronal activity similar to that seen in vivo (11)(12)(13).…”

mentioning

confidence: 99%

Morphine and opioid peptides reduce paraventricular neuronal activity: studies on the rat hypothalamic slice preparation.

Pittman¹,

Hatton²,

Bloom³

1980

Proc. Natl. Acad. Sci. U.S.A.

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Extracellular discharges of neurons in the paraventricular nucleus (PVN) were recorded from slices of rat hypothalamus in vitro. PVN neurons (n = 14) were identified by the criteria of (i) phasic activity patterns and (ii) antidromic invasion from the neurohypophysial tract. Neurons not displaying either of these features were considered unidentified with respect to physiological function (n = 85) The majority of unidentified neurons responded to bath application of morphine (1 pM), Met5] (2)(3)(4)(5) have demonstrated an opioidinduced antidiuresis attributed to stimulation of vasopressin release from the neurohypophysis. These studies are contrasted, however, by recent reports indicating reduced immunoreactive vasopressin in rat plasma after administration of morphine or opioid peptides (6, 7) and by reduced release of vasopressin from the neural lobe in vitro (8).These contradictory findings prompted us to examine the effects of morphine and the opioid peptides [D-Ala2, Me*]-enkephalin (an enkephalin analog more resistant to degradation) and ,B-endorphin on neuronal activity within the hypothalamic paraventricular nucleus (PVN). This nucleus contains cell bodies of vasopressin-and oxytocin-synthesizing neurons (among others) whose discharge frequency has been shown to correlate with hormone release from their terminals in the neurohypophysis (9, 10). Therefore, one might expect opiateinduced alterations in neurohypophysial secretion to be reflected in changes in the electrical activity of these neurons. We have looked for such effects, using the in vitro hypothalamic slice preparation, which demonstrates neuronal activity similar to that seen in vivo (11-13).The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "ad- KH2PO4, 0.4; CaCl2, 0.75; MgCl2, 0.5; MgSO4, 0.4; glucose,11; phenol red, 0.03; Hepes,10) and their upper surfaces were exposed to warmed, humidified oxygen. After a period of 1 hr, the level of the medium was raised above the surface of the slices, and oxygenated, warmed (35-370C) solution was perfused through the chamber at 1.5 ml/min. A stopcock manifold placed on the inflow line permitted introduction of drug-containing solutions without disrupting the flow of the perfusate. Stable, extracellular recordings could be obtained from the single neurons in the slices for periods of 8-10 hr.Recording. Extracellular recording in the PVN was carried out with glass micropipettes (5-10 MU) filled with 4% pontamine sky blue in 0.5 M sodium acetate. Action potentials were amplified and filtered, and, on occasion, photographed from the face of the oscilloscope. A variable voltage gate with a visible "window" selected suitable action potentials for integration of activity (displayed as firing rate on a chart recorder) or for spike train analysis on a MINC LAB II minicomputer (Digital Equipment, Maynard, MA; software by K. Liebold).Stimulation. A bipolar stimulation electrode of nichrome wire (outside diameter 100 ,um, ins...

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Phasic discharge in supraoptic neurones recorded from hypothalamic slices

Cited by 28 publications

References 8 publications

Responses of supraoptic neurones in the intact and deafferented rat hypothalamus to injections of hypertonic sodium chloride.

Responses of supraoptic neurones in the intact and deafferented rat hypothalamus to injections of hypertonic sodium chloride.

Electrophysiological studies of paraventricular and supraoptic neurones recorded in vitro from slices of rat hypothalamus.

Morphine and opioid peptides reduce paraventricular neuronal activity: studies on the rat hypothalamic slice preparation.

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