Plasticity of secretory neurons in the supraoptic and paraventricular nuclei of the hypothalamus on exposure to light

2006 ◽  
Vol 36 (5) ◽  
pp. 463-466
Author(s):  
S. V. Logvinov ◽  
A. V. Gerasimov ◽  
V. P. Kostyuchenko
Keyword(s):  
Paraventricular Nuclei ◽  
Secretory Neurons

Association of pituitary adenoma with neuronal christoma: A TEM study

1994 ◽  
Vol 52 ◽  
pp. 232-233
Author(s):  
Eva Horvath ◽  
Kalman Kovacs ◽  
B. W. Scheithauer ◽  
R. V. Lloyd ◽  
H. S. Smyth
Keyword(s):  
Growth Hormone ◽  
Pituitary Adenoma ◽  
Pituitary Tumor ◽  
Nervous Tissue ◽  
Alternative Explanation ◽  
Growth Hormone Releasing Hormone ◽  
Cell Hyperplasia ◽  
Releasing Hormone ◽  
Secretory Neurons

The association of a pituitary adenoma with nervous tissue consisting of neuron-like cells and neuropil is a rare abnormality. In the majority of cases, the pituitary tumor is a chromophobic adenoma, accompanied by acromegaly. Histology reveals widely variable proportions of endocrine and nervous tissue in alternating or intermingled patterns. The lesion is perceived as a composite one consisting of two histogenetically distinct parts. It has been suggested that the neuronal component, morphologically similar to secretory neurons of the hypothalamus, may initiate adenoma formation by releasing stimulatory substances. Immunoreactivity for growth hormone releasing hormone (GRH) in the neuronal component of some cases supported this view, whereas other findings such as consistent lack of growth hormone (GH) cell hyperplasia in the lesions called for alternative explanation.Fifteen tumors consisting of a pituitary adenoma and a neuronal component have been collected over a 20 yr. period. Acromegaly was present in 11 patients, was equivocal in one, and absent in 3.

HYPOTHALAMIC SEXUAL PRECOCITY IN FEMALE RATS OPERATED SHORTLY AFTER BIRTH

1962 ◽  
Vol 41 (2) ◽  
pp. 301-313 ◽  
Author(s):  
S. Horowitz ◽  
J. J. Van der Werff ten Bosch
Keyword(s):  
Anterior Commissure ◽  
Anterior Hypothalamus ◽  
Female Rats ◽  
Vaginal Opening ◽  
Sexual Precocity ◽  
Paraventricular Nuclei ◽  
Gonadotrophin Secretion ◽  
Electrolytic Lesions

ABSTRACT Electrolytic lesions were placed in the anterior hypothalamus of 3–4 day-old female rats; vaginal opening was hastened in comparison with blank-operated littermates in 12 of 17 rats bearing a lesion in the basal supra-and post-chiasmatic area. In the animals with the earliest vaginal opening, lesions reached upward towards the region of the anterior commissure and the paraventricular nuclei. The degree of advancement of puberty in rats operated at the age of 3 or 4 days was similar to that caused by lesions made at 10, 14 or 15 days. This finding suggests that the effect of a lesion upon gonadotrophin secretion does not begin to take place until after the age of at least two weeks.

PVN lesions prevent the endothelin 1-induced increase in arterial pressure and vasopressin

2001 ◽  
Vol 280 (2) ◽  
pp. E349-E356 ◽  
Author(s):  
Noreen F. Rossi ◽  
Haiping Chen
Keyword(s):  
Central Nervous System ◽  
Cerebrospinal Fluid ◽  
Arterial Pressure ◽  
Paraventricular Nuclei ◽  
Artificial Cerebrospinal Fluid ◽  
Electrolytic Lesions ◽  
The Central Nervous System ◽  
Baseline Values ◽  
Long Evans

Endothelin (ET) acts within the central nervous system to increase arterial pressure and arginine vasopressin (AVP) secretion. This study assessed the role of the paraventricular nuclei (PVN) in these actions. Intracerebroventricular ET-1 (10 pmol) or the ETA antagonist BQ-123 (40 nmol) was administered in conscious intact or sinoaortic-denervated (SAD) Long-Evans rats with sham or bilateral electrolytic lesions of the magnocellular region of the PVN. Baseline values did not differ among groups, and artificial cerebrospinal fluid (CSF) induced no significant changes. In sham-lesioned rats, ET-1 increased mean arterial pressure (MAP) 15.9 ± 1.3 mmHg in intact and 22.3 ± 2.7 mmHg in SAD ( P < 0.001 ET-1 vs. CSF) rats. PVN lesions abolished the rise in MAP: −0.1 ± 2.8 mmHg in intact and 0.0 ± 2.9 mmHg in SAD. AVP increased in only in the sham-lesioned SAD group 8.6 ± 3.5 pg/ml ( P < 0.001 ET-1 vs. CSF). BQ-123 blocked the responses. Thus the integrity of the PVN is required for intracerebroventricularly administered ET-1 to exert pressor and AVP secretory effects.

Specific alterations in sodium chloride intake after hypothalamic lesions in the rat

1963 ◽  
Vol 205 (5) ◽  
pp. 922-926 ◽  
Author(s):  
Miguel R. Covian ◽  
José Antunes-Rodrigues
Keyword(s):  
Sodium Chloride ◽  
Urinary Excretion ◽  
The Other ◽  
Urinary Output ◽  
Water Ingestion ◽  
Hypothalamic Lesions ◽  
Paraventricular Nuclei ◽  
Electrolytic Lesions ◽  
Specific Increase ◽  
Sodium Chloride Intake

Bilateral electrolytic lesions in the hypothalamus of the rat elicited either a decrease or increase in 2% NaCl intake, without a significant change in water ingestion. Lesions placed in the anterior hypothalamus involving supraoptic or paraventricular nuclei, or both, resulted in a conspicuous fall (as much as 93%) of NaCl intake. The decreased consumption remained to the end of the experiments which in some rats lasted 105 days and was accompanied by a decrease in NaCl urinary output. On the contrary, lesions placed in the central hypothalamus determined a specific increase of NaCl intake together with an augmented urinary excretion. The increased ingestion was permanent and lasted to the end of the experiment, attaining in one rat the value of 290%. To account for these results two provisional explanations are advanced, one of them considering the possibility of the existence of two areas of opposite effects regarding NaCl ingestion and the other claiming a neurohumoral mechanism in which oxytocin and aldosterone could be the two responsible hormones.

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