Electrical stimulation of tooth pulp increases the expression of c-fos in the cat supraoptic nucleus but not in the paraventricular nucleus

Life Sciences ◽  
1993 ◽  
Vol 53 (15) ◽  
pp. 1235-1241 ◽  
Author(s):  
Norio Matsumoto ◽  
Kei Kawarada ◽  
Ken-ichi Kamata ◽  
Takashi A. Suzuki
1991 ◽  
Vol 69 (7) ◽  
pp. 1035-1045 ◽  
Author(s):  
John Ciriello ◽  
Michael B. Gutman

The functional projections from pressor sites in the subfornical organ (SFO) were identified using the 2-deoxyglucose (2-DG) autoradiographic method in urethane-anesthetized, sinoaortic-denervated rats. Autoradiographs of brain and spinal cord sections taken from rats whose SFO was continuously stimulated electrically for 45 min with stereotaxically placed monopolar electrodes (150 μA, 1.5-ms pulse duration, 15 Hz) following injection of tritiated 2-DG were compared with control rats that received intravenous infusions of pressor doses of phenylephrine to mimic the increase in arterial pressure observed during SFO stimulation. Comparisons were also made to autoradiographs from rats in which the ventral fornical commissure (CFV), just dorsal to the SFO, was electrically stimulated. The pressor responses during either electrical stimulation of the SFO or intravenous infusion of phenylephrine were similar in magnitude. On the other hand, stimulation of the CFV did not elicit a significant pressor response. Electrical stimulation of the SFO increased 2-DG uptake, in comparison to the phenylephrine-infused rats, in the nucleus triangularis, septofimbrial nucleus, lateral septal nucleus, nucleus accumbens, bed nucleus of the stria terminalis, dorsal and ventral nucleus medianus (median preoptic nucleus), paraventricular nucleus of the thalamus, hippocampus, supraoptic nucleus, suprachiasmatic nucleus, paraventricular nucleus of the hypothalamus, and the intermediolateral nucleus of and central autonomic area of the thoracic spinal cord. In contrast, in rats whose CFV was stimulated, these nuclei did not demonstrate changes in 2-DG uptake compared with control animals that received pressor doses of phenylephrine. These data have demonstrated some of the components of the neural circuitry likely involved in mediating the pressor responses to stimulation of the SFO and the corrective responses to activation of the SFO by disturbances to circulatory and fluid balance homeostasis.Key words: cardiovascular reflex pathways, drinking, median preoptic nucleus, osmoreceptors, paraventricular nucleus of the hypothalamus, supraoptic nucleus.


1967 ◽  
Vol 166 (1005) ◽  
pp. 422-442 ◽  

By means of a simple method for extraction of blood samples, reliable recoveries of vasopressin and oxytocin were obtained. This method was used in anaesthetized cats for estimation of these hormones, released into external jugular venous blood, after localized electrical stimulation in the hypothalamus. Stimulation of the supraoptic nucleus or supraoptico-hypophysial tract released large amounts of vasopressin without oxytocin. Stimulation of the paraventricular nucleus or tractus paraventricular is cinereus (Greving) released moderate amounts of vasopressin alone. Stimulation at points in the tuberal region of the hypothalamus released oxytocin with or without vasopressin. These could lie on the caudal tract from the paraventricular nucleus (Laqueur).


1980 ◽  
Vol 58 (5) ◽  
pp. 574-576 ◽  
Author(s):  
J. Ciriello ◽  
F. R. Calaresu

In 10 cats anaesthetized with chloralose the electrical activity of spontaneously active hypothalamic units was recorded for changes in discharge rate during electrical stimulation of renal afferent nerves. The discharge rate of 141 single units was altered by stimulation of either the ipsilateral or contralateral renal nerves. Most of the responsive units were located in the regions of lateral preoptic nucleus, lateral hypothalamus, and paraventricular nucleus. These results demonstrate that renal afferent nerves provide information to hypothalamic structures known to be involved in the regulation of arterial pressure and fluid balance.


1985 ◽  
Vol 63 (7) ◽  
pp. 816-824 ◽  
Author(s):  
Michael B. Gutman ◽  
John Ciriello ◽  
Gordon J. Mogenson

It has recently been reported that stimulation of the region of the subfornical organ (SFO) elicits an increase in arterial pressure. However, the mechanisms and forebrain neural circuitry that are involved in this cardiovascular response have not been elucidated. The present study was done in urethane-anaesthetized rats to determine whether selective activation of SFO neurons elicit cardiovascular responses and whether these responses were mediated by a pathway involving the paraventricular nucleus of the hypothalamus (PVH). Stimulation sites which required the lowest threshold current (30 μA) to elicit a pressor response and at which the largest rise in mean arterial pressure (MAP; 22 ± 2 mmHg) was elicited at a constant current intensity (150 μA) were histologically localized in the region of the SFO. Short (mean peak latency; 4 ± 2 s) and long (mean peak latency; 61 ± 8 s) latency increases in MAP were observed during and after electrical stimulation of the SFO, respectively. Cardiac slowing accompanied the short latency pressor response and cardioacceleration was observed in most (57%) of the cases to accompany the late pressor response. Microinjection of L-glutamate into the SFO consistently elicited cardiovascular responses qualitatively similar to those observed during electrical stimulation. Ganglionic blockade abolished the short latency increase in MAP and the accompanying bradycardia. However, the long latency pressor and cardioacceleratory responses were not altered by ganglionic blockade and adrenalectomy. Selective bilateral electrolytic or kainic acid lesions of the region of the PVH significantly attenuated the cardiovascular responses elicited by stimulation of the SFO. These data suggest that activation of neurons in the SFO elicit cardiovascular responses partially mediated by sympathetic outflow through a neural pathway involving the PVH.


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