摘要:

The sleep-wakefulness pattern and brain protein levels were determined in rats for 3 h following these conditions: administration of an inhibitor of protein synthesis (anisomycin), administration of several doses of rat growth hormone (GH) or thyrotropin, and administration of a combination of anisomycin + GH or thyrotropin. Anisomycin inhibited sleep and increased wakefulness, GH increased REM sleep, and thyrotropin produced no change. The combined administration of GH and anisomycin returned sleep to control levels. Anisomycin produced a time-dependent decrease in brain protein levels, GH produced changes in brain protein levels as compared to controls in the second hour only, and thyrotropin had no effect upon brain protein levels. The results are discussed in terms of the possible relationship between sleep and proteins.

ISSN:0028-3835    

DOI:10.1159/000122377

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Plasma concentrations of growth hormone (GH) were determined in samples obtained sequentially at 15-min intervals during the last 4 h in monkeys deprived of sleep for 76 h and the first 8 h of ensuing recovery sleep. Electroencephalographic (EEG), electro-oculographic (EOG), and electromyographic (EMG) activities were recorded. Stages 3–4 sleep occurred rapidly after sleep onset and were of long duration. Plasma GH secretion was markedly elevated during sleep recovery, without apparent relationship to stage of slee

ISSN:0028-3835    

DOI:10.1159/000122378

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

A single dose of corticosterone (1 mg/kg b.w. i.p.) increased the 5-hydroxytryptamine (5-HT) content in the mesencephalon, amygdala and hypothalamus. The maximum was observed at 15 min following administration. The 5-HT level returned to normal between 60 and 180 min. The 5-hydroxyindoleacetic acid (5-HIAA) content decreased in the mesencephalon and hypothalamus at 15 min, and then increased to the maximum at 30 min in the mesencephalon and at 45 min in the hypothalamus and amygdala. There were no changes in the septum and hippocampus either in 5-HT or in 5-HIAA content following corticosterone administration. Desoxycorticosterone administration (1 mg/rat i.p.) was ineffective. Tritiated 5-HT uptake did not change in the hypothalamus and mesencephalon tissue in vitro after corticosterone or desoxycorticosterone treatment. Adrenalectomy caused a decrease in the 5-HT content in all brain areas studies. 5-HIAA decreased only in the hypothalamus. Corticosterone administration normalized the 5-HT and 5-HIAA content in the hypothalamus and mesencephalon in adrenalectomized rats. Tritiated 5-HT uptake was lower in the hypothalamus and mesencephalon in adrenalectomized rats. Corticosterone administration increased the activity back to normal in the hypothalamus, however desoxycorticosterone was ineffective. The data suggest that the plasma corticosterone level plays a role in the regulation of the activity of the serotoninergic system in certain limbic brain structures.

ISSN:0028-3835    

DOI:10.1159/000122379

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Several estrogenic compounds were examined for their abilities to stimulate the formation of adenosine 3’,5’-monophosphate (cyclic AMP) in incubated hypothalami from immature (27–28 day old) female rats. 17-β estradiol (E2) and diethylstilbestrol (DES) significantly increased the formation of cyclic AMP while estrone and estriol elicited small but not statistically significant increases in cyclic AMP formation. 17-α estradiol was ineffective in increasing cyclic AMP formation. The anti-estrogenic agent clomiphene was found to effectively antagonize the formation of cyclic AMP elicited by E2 and DES, while having no stimulatory effects on cyclic AMP formation itself. These data indicate that the binding of estrogenic compounds to cytoplasmic sites (receptors) in the hypothalamus is required for subsequent stimulation of cyclic AMP fo

ISSN:0028-3835    

DOI:10.1159/000122380

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Adrenocorticotropic abilities in basal and stress conditions, and the responsiveness of ectopically-transplanted pituitaries to hypothalamic stimulation were investigated in adult red Carneau pigeons. In birds with pituitary autografts, both electrical stimulation of the hypothalamus and restraint stress elicited a significant increase in the plasma corticosterone level, however these adrenal cortical responses were not so important as those in intact pigeons. Ether stress, which was a very effective stimulus of adrenocortical activity in controls, did not result in any plasma corticosterone elevation in pigeons that had been operated on. Such a decrease in the functional abilities of ectopic adrenocorticotropic cells was interpreted as the result of an impaired hypothalamic control acting via the systemic bloodstream. This hypothesis was corroborated by a moderate reduction in diurnal variations of the plasma corticosterone level in birds with autografts with respect to intact pigeons. Adenohypophysectomized controls did not show any adrenocortical response either to hypothalamic stimulation or to stress application.

ISSN:0028-3835    

DOI:10.1159/000122381

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Average evoked responses (AERs) were recorded simultaneously from 3 hypothalamic nuclei of freely behaving rats. Permanent semi-microelectrodes were implanted 6–8 days before experiments were begun. The amygdaloid AER to 32 successive stimuli consisted of large amplitude potentials made up of 3 components (P1, N1 and P2) with short latencies. The neuronal recovery function (NRF) was short. However, the acoustic AER to 32 successive acoustic stimuli in anterior hypothalamus (AH), ventromedial hypothalamus (VMH), and arcuate nucleus (AN) consisted of large amplitude potentials of long duration made up of 5 components (P1 N1, P2, N2 and P3) with long latencies. The NRF was long. Intraperitoneal administration of L-dopa heightened the amplitude of the acoustic AER and shortened the NRF in VMH and AN. Reserpine administration 2 h after L-dopa maintained these phenomena in VMH and AN without alteration of the AER and NRF in AH. When reserpine was administered first, enhancement of the acoustic AER and shortening of the NRF was again obtained only in VMH and AN. L-dopa injection after reserpine treatment maintained these phenomena. Low doses of pentobarbital after L-dopa and reserpine and vice versa caused a marked increase in the acoustic AER and a shortening of the NRF in all recording sites. The amygdala AER and NRF, however, were not altered by any treatment or in any recording site

ISSN:0028-3835    

DOI:10.1159/000122382

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

All neural connections entering the hypothalamus from the anterior direction were severed by means of a Halász knife-cut in female rats at 22 days of age. The rats were then examined for vaginal opening and ovulation. At intervals blood samples were collected by cardiac puncture for the measurement of serum corticosterone (B). Unoperated rats showed vaginal opening at 36.5 ± 2.1 days and ovulation within 2 days. A significant difference was found between B at 08.00 h and 18.00 h at the first sample interval chosen (28 days of age) and thereafter. Animals given sham surgery showed vaginal opening late (44.2 ± 3.2 days, p < 0.05) but ovulated within 2 days. These animals also had a significant 08.00–18.00 difference in B from day 28 on. Rats with frontal cuts in front of the suprachiasmatic nucleus (SCN) showed precocious vaginal opening (27.2 ± 2.3 days, p < 0.05) and early ovulation (28.2 ± 0.7 days). A 08.00–18.00 difference was noted at 28 days of age but was lost after ovariectomy at 47 days of age. Implantation of a silastic estradiol benzoate capsule restored the 08.00–18.00 difference (p < 0.01). Animals with cuts behind the optic chiasm (posterior frontal cuts) all showed early vaginal opening; some rats then ovulated (at 42.3 ± 3.8 days) while others did not. No difference could be detected in the position of the cuts although there appeared to be more damage to the region just behind the SCN in the latter group. No 08.00–18.00 difference in B was found in the nonovulatory group and no difference was found in the ovulatory group until 44 days of age. It can be concluded that an isolated hypothalamic island containing the SCN will generate signals sufficient for precocious ovulation although subsequent ovulatory cycles ar

ISSN:0028-3835    

DOI:10.1159/000122383

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

The hypothalamic preoptic area (POA) was electrically stimulated through permanently implanted electrodes in 4 unanesthetized sheep. Initiation of POA stimulation was followed within 10–20 min by large increases in plasma levels of prolactin (PRL). The stimulation-induced discharges of PRL were consistently observed in both untreated and estradiol-treated castrated animals using 0.1 to 0.7 mA of applied current. Since behavioral modifications were only sometimes associated with electrical stimulation of the POA, the response appears unrelated to the stress-induced release of PR

ISSN:0028-3835    

DOI:10.1159/000122384

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Preincubation of synaptosome-rich homogenates of rat hypothalamus with melatonin resulted in significant decreases of norepinephrine, serotonin, dopamine and glutamate uptake. Melatonin inhibition was noncompetitive; apparent Km’s of initial uptake processes were: (2.5 ± 0.3) × 10–7Mfor norepinephrine, (2.6 ± 0.3) × 10–7Mfor serotonin, (2.4 ± 0.4) × 10–7Mfor dopamine and (1.0 ± 0.3) × 10–7Mfor glutamate. Apparent K¡’s for melatonin inhibition of transmitter uptake were: 0.64 ± 0.14 mM (norepinephrine), 0.23 ± 0.03 mM (serotonin), 0.51 ± 0.08 mM (dopamine) and 1.21 ± 0.10 mM (glutamate). Transmitter release evoked by increasing [K+] in medium to 30 mM was augmented by melatonin in a dose-dependent manner. Maximal effects were observed on serotonin release. Accumulation of 3H-melatonin within synaptosome-rich homogenates did not exhibit differences between 0 and 37 °C, indicating that the uptake of the hormone was not an active process. These results suggest that exogenously-administered melatonin may affect neurotransmitter accumulation and release in the hypothalamus by modification of the transmitter uptake mechanism rather than by competition with the transm

ISSN:0028-3835    

DOI:10.1159/000122385

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Immature female rats, raised in either cyclic light (LD; 14 h light/10 h dark) or constant light (LL) were divided into 4 groups and given daily injections of estradiol benzoate (5, 10, or 25 ng) in 0.1 ml sesame oil starting at 24 days of age. Control animals received oil only. Injections were continued until vaginal opening (V.O.). Half of each group of animals was killed and dissected 1 day after V.O. Results indicate that both LL exposure and EB treatment accelerated sexual maturation (as indicated by the day of V.O.) with a significant interaction between the 2 treatments. The greatest difference in age at V.O. between LD and LL rats was observed at a dose of 10 ng EB/day. Body weights and uterine weights decreased with higher doses of EB, apparently reflecting the younger age at the time of V.O. No significant differences in ovarian weights were observed. Results are interpreted to indicate that increased exposure to light may change the sensitivity of the hypothalamic-pituitary axis to the positive feedback of estrogen.

ISSN:0028-3835    

DOI:10.1159/000122386

出版商:S. Karger AG    

年代:1975

数据来源: Karger