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Biomedical subjects

M Jouvet

Publications and source records attributed to M Jouvet.

At least 145 records · Page 8Linked to original sources
PubMed1988

Endogenous L-dopa, its immunoreactivity in neurons of midbrain and its projection fields in the cat.

L-DOPA (L-3,4-dihydroxyphenylalanine) immunoreactivity was demonstrated in neurons of the cat ventral midbrain and its projection areas, using an immunohistochemical method in conjunction with a newly developed highly specific anti-L-DOPA serum. L-DOPA-immunoreactive (IR) neurons were found in the substantia nigra, retrorubral area and ventral tegmental area of Tsai. L-DOPA-labeled fibers and terminals were hardly detectable in the nigrostriatal pathway and in the caudate nucleus which showed very intense dopamine-immunoreactivity. In contrast, many short labeled processes were detectable in the central amygdala and, although very few in number, in the entorhinal cortex.

Animals↗
PubMed1988

The nuclei of origin of monoaminergic, peptidergic, and cholinergic afferents to the cat nucleus reticularis magnocellularis: a double-labeling study with cholera toxin as a retrograde tracer.

Using a sensitive double-immunostaining technique with nonconjugated cholera toxin B subunit (CT) as a retrograde tracer, we examined the cells of origin and the histochemical nature of afferents to the cat nucleus reticularis magnocellularis (Mc) of the medulla oblongata. After injections of CT confined to the Mc, we found that the major afferents to the Mc arise from: (1) the lateral part of the bed nucleus of the stria terminalis, the nucleus of the anterior commissure, the preoptic area, the central nucleus of the amygdala, the posterior hypothalamus, and the nucleus of the fields of Forel; (2) the Edinger-Westphal nucleus, the mesencephalic reticular formation, and the ventrolateral part of the periaqueductal grey; (3) the nuclei locus coeruleus alpha (LC alpha), peri-LC alpha, locus subcoeruleus, and reticularis pontis oralis and caudalis; (4) the caudal raphe nuclei; and (5) the nucleus reticularis ventralis of the medulla.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1988

Hypophysectomy does not disturb the sleep-waking cycle in the cat.

The ablation of the hypophysis does not disturb the basic waking-sleep cycle. Further, this intervention fails to modify the recovery of sleep after instrumental paradoxical sleep deprivation as well as after injection of 5-hydroxytryptophan in parachlorophenylalanine-pretreated insomniac cats. These results demonstrate that the hypophysis does not play a significant role in sleep mechanisms. We discuss these data in view of a possible regulation of the sleep-waking cycle by hypothalamo-hypophyseal hormones.

Animals↗
PubMed1988

Immunohistochemistry of aromatic L-amino acid decarboxylase in the cat forebrain.

The topographic distribution of aromatic L-amino acid decarboxylase (AADC)-immunoreactive (IR) neurons was investigated in the cat hypothalamus, limbic areas, and thalamus by using specific antiserum raised against porcine kidney AADC. The perikarya and main axons were mapped on an atlas in ten cross-sectional drawings from A8 to A16 of the Horsley Clarke stereotaxic plane. AADC-IR neurons were widely distributed in the anterior brain. They were identified in the posterior hypothalamic area, rostral arcuate nucleus of the hypothalamus, dorsal hypothalamic area, and periventricular complex of the hypothalamus, which contain tyrosine hydroxylase (TH)-IR cells and are known as A11 to A14 dopaminergic cell groups. AADC-IR perikarya were also found in the other hypothalamic areas where few or no TH-IR cells have been reported: the supramamillary nucleus, tuberomamillary nucleus, pre- and anterior mamillary nuclei, caudal arcuate nucleus, dorsal hypothalamic area immediately ventral to the mamillothalamic tract, anterior hypothalamic area, area of the tuber cinereum, retrochiasmatic area, preoptic area, suprachiasmatic and dorsal chiasmatic nuclei. We also identified them in the anterior commissure nucleus, bed nucleus of the stria terminalis, stria terminalis, medial and central amygdaloid nuclei, lateral septal nucleus, and nucleus of the diagonal band of Broca. AADC-IR neurons were localized in the ventromedial part of the thalamus, lateral posterior complex, paracentral nucleus and lateral dorsal nucleus of the thalamus, medial habenula, parafascicular nucleus, subparafascicular nucleus, and periaqueductal gray. Conversely, we detected only a few AADC-IR cells in the supraoptic nucleus whose rostral portion contains TH-IR perikarya. Comments are made on the relative localizations of the AADC-IR and TH-IR neurons, on species differences between the cat and rat, as well as on the possible physiological functions of the enzyme AADC.

Animals↗
PubMed1988

Topography of neurophysin-immunoreactive neurons projecting to the neurohypophysis: direct evidence as revealed by a double staining method.

The topographic distribution of neurophysin-immunoreactive (NP-IR) cells projecting to the posterior pituitary gland has been studied in the cat using a double staining method: immunohistochemistry of neurophysin in conjunction with horseradish peroxidase (HRP) retrograde tracer technique. We found that almost all the hypothalamic NP-IR cells project directly to the neurohypophysis except those localized in the suprachiasmatic nucleus and in the caudal part of the paraventricular nucleus.

Animals↗
PubMed1988

Hypophysectomy in monosodium glutamate-pretreated rats suppresses paradoxical sleep rebound.

Control untreated and pretreated female rats at birth with 10 injections of monosodium glutamate (MSG, 4 mg/g b. wt.) were hypophysectomized (HYPX) at 45-60 days of age and their sleep-waking cycle continuously registered. In control rats, hypophysectomy was followed by a 35.7% decrease in paradoxical sleep (PS) duration while it has no effect on the sleep of MSG-treated rats. After 24 h of PS deprivation, there was a normal immediate rebound of PS in the control HYPX and MSG rats while there was no significant rebound in the HYPX-MSG-treated rats. It is concluded that neuropeptides from arcuate nucleus and hypophysis are involved in a PS rebound mechanism.

Animals↗
PubMed1988

Localization of CRF-immunoreactive neurons in the cat medulla oblongata: their presence in the inferior olive.

Corticotropin releasing factor (CRF)-immunoreactive (IR) perikarya, visualized by the indirect immunoperoxidase method in colchicine-pretreated cats, were localized in many discrete regions of the medulla oblongata. They were found mainly in the dorsal aspect and midline of the medulla oblongata, and more rostrally in the ventrolateral portion. Our results also demonstrated CRF-IR neurons in the rostrocaudal extent of the inferior olive, probably projecting to the cerebellar cortex via thick axons visualized along the lateral edge of the medulla. CRF-IR olivary cells were also found in the pontine cat from which the forebrain was removed, but neither in hypophysectomized nor adrenalectomized cats.

Animals↗
PubMed1988

Evidence for histaminergic arousal mechanisms in the hypothalamus of cat.

Polygraphic 23-hr recordings were carried out in 25 adult cats in order to examine the effects of both systemic and local injections of various histaminergic and antihistaminergic drugs on sleep-waking cycles. alpha-Fluoromethylhistidine (alpha-FMH), a specific inhibitor of histidine decarboxylase, when injected intraperitoneally at a dose of 20 mg/kg, induced a significant increase in deep slow wave sleep (S2) and a decrease in wakefulness (W), without modifying light slow wave sleep (S1) and paradoxical sleep (PS). Intraperitoneal injections of mepyramine (1 mg and 5 mg/kg), a well-known histamine H1-receptor antagonist, increased deep slow wave sleep and decreased wakefulness, as well as paradoxical sleep. Bilateral injections of alpha-FMH (50 micrograms/1 microliter) into the ventrolateral posterior hypothalamus, where histamine immunoreactive neurones have been recently identified, resulted in a significant decrease in wakefulness and increase in deep slow wave sleep. Similarly, injections of mepyramine (120 micrograms/1 microliter) in the same structures caused a significant decrease in wakefulness and an increase in deep slow wave and paradoxical sleep as well. In contrast, local injections of SKF-91488 (50 micrograms/1 microliter), a specific inhibitor of histamine-N-methyltransferase, led to a significant increase in wakefulness and decrease in both slow wave sleep (SWS) and paradoxical sleep. Injections of histamine, at doses of 5, 30 and 60 micrograms/1 microliter, also increased wakefulness and decreased slow wave sleep dose dependently, while these effects were completely blocked by pretreatment with mepyramine. The results suggest that histaminergic systems in the hypothalamus play an important role in arousal mechanisms and their actions are mediated through H1-receptors.

Animals↗
PubMed1988

Successful treatment of idiopathic hypersomnia and narcolepsy with modafinil.

1. Modafinil, a putative central alpha 1 adrenergic agonist, was tested in idiopathic hypersomnia and narcolepsy. 2. Sleep attacks and drowsiness were significantly decreased in 83% of 18 hypersomniac subjects and 71% of 24 narcoleptics. 3. When cataplectic episodes were not totally suppressed the association of a low dose of Clomipramine was successful in improving them. 4. Modafinil, used for at least 3 years in some patients, produces, in most cases, no peripheric sides effects, does not disturb night sleep and is never responsible of tolerance of drug dependence.

Adrenergic alpha-Agonists↗
PubMed1988

Immunohistochemistry of tyrosine hydroxylase and phenylethanolamine N-methyltransferase in the human brain stem: description of adrenergic perikarya and characterization of longitudinal catecholaminergic pathways.

Using immunocytochemical method in conjunction with antibodies to tyrosine hydroxylase and phenylethanolamine N-methyltransferase, catecholaminergic cell groups and axon pathways are mapped in the human hind brain. Adrenergic perikarya are located mainly in the rostral medulla, as in lower animals, and contribute a subset of axons to the main longitudinal catecholaminergic bundle which runs through the medulla oblongata, pons and midbrain such as the dorsal part of the central nucleus of the medulla oblongata, the parvocellular reticular formation ventromedial to the facial nerve and ventrolateral to the locus coeruleus. Adrenergic terminals are present in the locus coeruleus and other medullary and pontine structures. The locus coeruleus contains only tyrosine hydroxylase-immunoreactive cells and appears to be the source of a discrete dorsal catecholaminergic bundle which runs through the central tegmental field just ventrolateral to the periaqueductal gray of the rostral pons and mesencephalon and which does not contain adrenergic axons. A ventral catecholaminergic bundle arising in the medullary cells does contain a subset of adrenergic axons in the mesencephalic tegmental field. These two longitudinal axon bundles run near each other in the mesencephalic reticular formation. Additional descriptions are provided of catecholaminergic axons near the dorsal and ventral surface of the human medulla.

Adrenergic Fibers↗
PubMed1988

Effects of hypophysectomy on the sleep of neonatally monosodium glutamate-treated rats.

Monosodium Glutamate (MSG), known to induce neuronal cell degeneration of the arcuate nucleus of the hypothalamus, was subcutaneously injected (4 mg/g body wt.) at postnatal days 1 to 5 or 1 to 10 in female rats. Hypophysectomy was performed at 45-60 days of age. Sleep parameters were continuously recorded for at least 7 days. Results indicated that hypophysectomized (HYPX) NaCl-treated rats showed an increase of Slow Wave Sleep (SWS) (+29.6%) and a decrease of Paradoxical Sleep (PS) (-36.7%) durations. In MSG-treated rats, hypophysectomy did not alter SWS durations but it increased PS durations as MSG dosing increased. It was concluded that arcuate nucleus neurons seemed to be not critically involved in sleep production mechanisms.

Aging↗
PubMed1988

Localization of cerebral protein synthesis alterations in response to water deprivation in rats.

The effects of 2 days of water deprivation on local rates of methionine incorporation into protein in 54 brain and 5 circumventricular structures of conscious freely moving rats have been examined by means of a recently developed quantitative autoradiographic method with L-[35S]-methionine. The results show that 2 days of water deprivation does not affect methionine metabolism in the majority of the brain areas analyzed, but reveals selective increases in the hypothalamoneurohypophyseal system, in cerebral structures surrounding the third ventricle, in the locus ceruleus, raphe dorsalis, nucleus ambiguus and hippocampal CA3 layer. In contrast, decreases were observed in the central amygdala, lateral habenula and interpeduncular nucleus. Although the highest increases were located in brain areas involved in body fluid homeostasis, several aspecific responses, perhaps due to chronic stress, were also observed, notably in the locus ceruleus, raphe dorsalis and in a restricted number of limbic system structures.

Animals↗
PubMed1988

[Opposite variations of extracellular concentrations of 5-hydroxyindoleacetic acid (5-HIAA) measured by voltammetry of axonal terminals and cell bodies of the dorsal raphe nucleus through the sleep-wake cycle].

Differential pulse voltammetry was used for 5-hydroxyindoleacetic acid (5-HIAA) detection in the rat caudate (n. Cd) and Raphe Dorsalis (n. RD) nuclei, in chronic experimental conditions. In the anterior and ventral part of n. RD, large increases in the extracellular concentrations of 5-HIAA were reported during slow wave sleep (SWS) and paradoxical sleep (PS) whereas a decrease occurred during waking. These variations could reflect the dendritic release of serotonin. In n. Cd, opposite variations of the extracellular concentrations of 5-HIAA were observed i.e. increase during waking state and decrease during SWS and PS.

Animals↗
PubMed1988

[Hypothermia and paradoxical sleep. I. Pontile cats without hypothalamo-hypophysis].

Chronic pontile cats (without hypothalamo-hypophysis) were kept during 4 days at central T (TC) between 37.5 and 30.8 degrees C at stable ambiant T (TA) between 28.5 and 23 degrees C. The vasomotor index of the forepaw was chosen for studying change in vasomotricity. Small and slow variations of TA (+1.5 degrees C) around 27 degrees C were followed by thermoregulatory response since a progressive decrease of TA under 27 degrees C led to vasoconstriction and increase of TC while progressive increase of TA above 27 degrees C led to vasodilatation and decrease of TC. However rapid and large decrease of TA under 27 degrees C (24-23 degrees C) led to the expected hypothermia with decrease of TC but without vasoconstriction. Paradoxical sleep (PS) amounts were strongly correlated with TC. At TC above 35.5 degrees C PS was almost totally suppressed while it increased significantly under 35 degrees C (Q10 = 0.10). Under 35 degrees C at stable TC and TA, PS occurred with an endogenous circahoral rhythm which did not vary significantly between 35 and 32 degrees C. These results strongly suggest that in pontile cats, PS is both gated and regulated by TC, while TC is regulated by pontobulbar vasomotor systems in response to TA. The putative role of the ventro-lateral medulla, in controlling both vasomotricity, TC and the excitability of the locus coeruleus is discussed in relation with PS.

Animals↗
PubMed1988

[Circadian rhythms of slow-wave sleep and paradoxical sleep are in opposite phase in genetically hypoprolactinemic rats].

In eleven genetically hypoprolactinemic rats (IPL nude rats) and five control rats (OFA), the sleep-waking cycle was continuously registered for 14 days at two ambient temperatures. At 23 degrees C, the slow wave sleep (SWS) duration of IPL rats was significantly higher (+6.8%, t = 5.4, p less than 0.001) than that of control rats, while the paradoxical sleep (PS) duration was lowered by 31.8% (t = 9.4, p less than 0.001). The circadian rhythm of PS disappeared while that of SWS persisted unchanged. At 30 degrees C, both sleep durations reached the level of control rats. The circadian rhythm of PS was however completely reversed: the PS acrophase was at 01 h while that of SWS was at 12 hrs. This first observation of spontaneous dissociation of the two states of sleep supports the hypothesis of two distinct circadian clocks, one for SWS, another for PS. It is suggested that hypothalamic prolactin and/or other still unknown genetic alterations might be responsible for the observed change in the PS circadian rhythm.

Animals↗