Electron-microscopic characteristics of neuroendocrine neurons in the amygdaloid body of the brain in male rats and female rats at different stages of the estral cycle

2008 ◽  
Vol 38 (1) ◽  
pp. 31-35
Author(s):  
A. V. Akhmadeev ◽  
L. B. Kalimullina
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Amygdaloid Body ◽  
Electron Microscopic ◽  
Estral Cycle ◽  
Neuroendocrine Neurons ◽  
The Brain

scholarly journals Local Cerebral Glucose Utilization in Normal Female Rats: Variations during the Estrous Cycle and Comparison with Males

1985 ◽  
Vol 5 (3) ◽  
pp. 393-400 ◽  
Author(s):  
Astrid Nehlig ◽  
Linda J. Porrino ◽  
Alison M. Crane ◽  
Louis Sokoloff
Keyword(s):  
Estrous Cycle ◽  
Glucose Utilization ◽  
Brain Regions ◽  
Female Rats ◽  
Male Rats ◽  
Normal Male ◽  
Normal Female ◽  
Female Rat ◽  
Males And Females ◽  
The Brain

The quantitative 2-[14C]deoxyglucose autoradiographic method was used to study the fluctuations of energy metabolism in discrete brain regions of female rats during the estrous cycle. A consistent though statistically nonsignificant cyclic variation in average glucose utilization of the brain as a whole was observed. Highest levels of glucose utilization occurred during proestrus and metestrus, whereas lower rates were found during estrus and diestrus. Statistically significant fluctuations were found specifically in the hypothalamus and in some limbic structures. Rates of glucose utilization in the female rat brain were compared with rates in normal male rats. Statistically significant differences between males and females at any stage of the estrous cycle were confined mainly to hypothalamic areas known to be involved in the control of sexual behavior. Glucose utilization in males and females was not significantly different in most other cerebral structures.

N-(3,5-dinitrophenyl)-5-methoxytryptamine, a novel melatonin antagonist: effects on sexual maturation of the male and female rat and on oestrous cycles of the female rat

1988 ◽  
Vol 116 (1) ◽  
pp. 43-53 ◽  
Author(s):  
M. Laudon ◽  
Z. Yaron ◽  
N. Zisapel
Keyword(s):  
Drinking Water ◽  
Adult Female ◽  
Sexual Maturation ◽  
Young Male ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Simultaneous Administration ◽  
Serum Concentrations ◽  
The Brain

ABSTRACT N-(3,5-dinitrophenyl)-5-methoxytryptamine (ML-23) has recently been synthesized and shown to antagonize the inhibitory effect of melatonin on the release of dopamine in vitro from the hypothalamus of female rats. In the present study the ability of ML-23 to inhibit in vivo the following melatonin-mediated effects was investigated: (1) delayed sexual maturation of young male rats, (2) delayed sexual maturation of young female rats, (3) inhibition of ovulation in mature female rats and (4) re-establishment of oestrous cycles in adult female rats maintained in continuous light. The inhibitory effect of daily melatonin injections, given in the afternoon, on the growth of the prostate gland and seminal vesicles and on serum testosterone concentrations in young male rats was prevented by daily injections of ML-23. Daily injections of ML-23 alone did not affect sexual maturation of young rats. In young male rats treated through the drinking water with melatonin, the growth of the accessory sex organs, but not that of the testes, was delayed and serum concentrations of testosterone were lower than in untreated rats. Administration of ML-23 through the drinking water increased serum concentrations of testosterone but did not significantly affect the weights of the accessory sex organs. Simultaneous administration of ML-23 and melatonin through the drinking water prevented completely, in a dose-dependent manner, the melatonin-mediated decrease in epididymal weights and in serum concentrations of testosterone and partially inhibited the delayed growth of the prostate glands and seminal vesicles. In young female rats treated with melatonin through the drinking water for 30 days, the growth of the ovaries was inhibited and serum concentrations of oestradiol were lower than in untreated rats. The growth of the uterus was not significantly affected. Administration of ML-23 through the drinking water did not significantly affect uterine and ovarian weights or oestradiol concentrations. Simultaneous administration of melatonin and ML-23 through the drinking water prevented completely the melatonin-mediated decrease in ovarian weights and in serum oestradiol concentrations. Ovulation during presumptive oestrus was prevented in adult female rats treated through the drinking water for 7 days with melatonin. Administration of ML-23 alone did not significantly affect the average numbers of ova shed and corpora lutea present. Simultaneous administration of ML-23 and melatonin prevented completely the melatonin-mediated inhibition of ovulation; the average number of ova shed was the same as in controls. Suppression of reproductive cycles occurred in adult female rats after long-term exposure to continuous light. This suppression was prevented by daily injections of melatonin in the afternoon; the incidence of constant oestrus decreased by 80%. Simultaneous injection of ML-23 and melatonin into rats maintained under continuous illumination prevented the effect of melatonin, and all the animals remained in constant oestrus. Administration of ML-23 alone did not alter the incidence of constant oestrus. A tritium-labelled derivative of ML-23 was prepared and administered orally to male rats. Peak concentrations of ML-23 occurred in the blood within 30 min after feeding and disappeared subsequently with a half-life of about 42 min. Intraperitoneal injection of [3H]ML-23 resulted in the appearance of peak concentrations of the drug in the brain within 20 min. The effects of ML-23 on serotonin S1 and S2 receptors, dopamine D2 receptors and melatonin receptors in the brain of the male rat were investigated using [3H]serotonin, [3H]spiperone and 2-[125I]iodomelatonin respectively. The binding of [3H]serotonin to brain synaptosomes and of [3H]spiperone to synaptosomes prepared from the cortical and caudate regions of the cerebrum was unaffected by ML-23 (10 μmol/l), whereas the binding of 2-[125I]iodomelatonin to brain synaptosomes was entirely inhibited. The results demonstrate the potency of ML-23 in antagonizing melatonin-mediated effects in the male and female rat in vivo. The drug may be administered to the animals simply through the drinking water, for relatively long periods without apparent deleterious effects on survival and welfare. ML-23 is accessible to both central and peripheral sites and acts specifically on melatonin but not on serotonin or dopamine receptors in the brain. The availability of a melatonin antagonist offers new opportunities for exploring the physiological role of melatonin in the neuroendocrine system. J. Endocr. (1988) 116, 43–53

scholarly journals The Effect of Gender on Brain Tissue Changes Induced by Renal Ischemia-Reperfusion Injury in Adult Rats

2019 ◽  
Vol 8 (2) ◽  
pp. 113-118
Author(s):  
Fakhri Armin ◽  
Fariba Azarkish ◽  
Ali Atash Ab Parvar ◽  
Aghdas Dehghani
Keyword(s):  
Brain Tissue ◽  
Inflammatory Responses ◽  
Ischemia Reperfusion ◽  
Left Kidney ◽  
Renal Ischemia ◽  
Female Rats ◽  
Male Rats ◽  
Adult Rats ◽  
Sensitive Organ ◽  
The Brain

Background: Renal ischemia-reperfusion (RIR) is a common clinical injury that affects the function of other remote organs such as the brain by initiating a cascade of complex and wide-ranging inflammatory responses. RIR also follows a different course in men and women. Since there is little information on the effect of RIR on the brain as a sensitive organ in both males and females, the present research was performed to investigate the effect of gender on RIR-induced brain tissue alterations in adult rats. Materials and Methods: In this study, 28 Wistar rats (14 female and 14 male rats) weighing 200 ± 20 g were divided into the following groups: 1- male sham (MS), 2- female sham (FS), 3- male ischemia (MI) with 3-hour reperfusion (ISC3hr), and 4- Female ischemia (FI) with 3-hour reperfusion (ISC3hr). Bilateral renal ischemia was induced for 45 minutes and blood samples were taken after reperfusion for the measurements of serum blood urea nitrogen (BUN), creatinine (Cr), malondialdehyde (MDA), and nitrite levels. The left kidney was removed for evaluation of MDA and tissue nitrite levels. Right kidney and brain tissue underwent histological examination. Results: Serum BUN level increased in both genders. Serum nitrite level was significantly different between both genders, meaning that it was increased in the female rats as compared to male ones. Overall brain tissue damage was significantly increased in males compared to females. Conclusion: RIR has an effect on the function and tissue of kidney and brain in both genders. Female rats are more susceptible to the nitric oxide system than the male ones. This study showed that male brain tissue was more susceptible to RIR. Therefore, gender is one of the important factors that should be considered in clinical treatments.

scholarly journals Sex Differences in the Brain-Blood Barrier in Rats Exposed to Early life Stress and the Treatment with Antidepressants and Psychobiotic

2021 ◽  
Author(s):  
Maria Eduarda M. Botelho ◽  
Anelise S. Carlessi ◽  
Luana M. Manosso ◽  
Laura A. Borba ◽  
Airam B. de Moura ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Life Stress ◽  
Early Life Stress ◽  
Maternal Deprivation ◽  
Female Rats ◽  
Male Rats ◽  
Major Depressive ◽  
Male And Female Rats ◽  
The Brain ◽  
Age And Sex

Abstract Major depressive disorder is a debilitating mental disorder. Although the etiology is not fully understood, the impairment to the blood-brain barrier (BBB) integrity may be involved. Maternal deprivation was performed in the first 10 postnatal days for 3h/day. Male and female rats were divided into control and maternal deprivation. Maternal deprivation animals were subdivided and received treatment with saline, escitalopram, ketamine, or probiotic. The integrity of BBB was evaluated in the prefrontal cortex and hippocampus at postnatal days 11, 21, 41, and 61. Maternal deprivation caused BBB breakdown in the prefrontal cortex and hippocampus in female and male rats in all ages evaluated, except in the prefrontal cortex of females at postnatal day 41. In females, escitalopram, ketamine, and probiotic reversed BBB breakdown in all ages evaluated, except probiotic at postnatal day 21 (prefrontal cortex), and ketamine at postnatal days 21 and 41 (hippocampus). In males, escitalopram, ketamine, and probiotic reversed BBB breakdown in the prefrontal cortex in all ages evaluated, except escitalopram at postnatal days 41 and 61. In the hippocampus of males, BBB damage was reversed by escitalopram at postnatal day 21 and ketamine at postnatal day 41. Treatment with escitalopram, ketamine, or probiotics can prevent changes in the BBB integrity, depending on the age and sex of the animal. Clinically it is important to evaluate different treatments depending on age and sex.

Amygdala in the regulation of reproductive functions during absence epilepsy

2017 ◽  
Author(s):  
Индира Садртдинова ◽  
Indira Sadrtdinova ◽  
Зухра Хисматуллина ◽  
Zuhra Hismatullina
Keyword(s):  
Sex Hormones ◽  
Absence Epilepsy ◽  
Female Rats ◽  
Ultrastructural Changes ◽  
Amygdaloid Body ◽  
Reactive Changes ◽  
Cortical Nucleus ◽  
17Β Estradiol ◽  
First Time ◽  
The Brain

The monograph deals with the problems of general morphology of the amygdaloid body and for the first time the assessment of structural and functional changes in the anterior cortical nucleus of the amygdaloid body of the brain of WAG/Rij female rats (the recognized model of man’s absence epilepsy) in response to the modulating influence of sex hormones is made by means of a modern complex of research methods (electrophysiological, morphometric, histologic, immunohistochemical, submicroscopical and statistical ones). The changes in the electroencephalographic parameters of the anterior cortical nucleus, the reactive changes in neurons, glial anterior cortical nuclei of the amygdaloid body of the brain of WAG/Rij female rats at sex hormones deficiency and after the substitution therapy with 17β-estradiol in combination with progesterone are described in detail. The results of immunohistochemical analysis of astrocytic glia, of the analysis of synapsoarchitectonics and ultrastructural changes in neurons, glial cells, neuropil of the anterior cortical nucleus of the amygdaloid body of WAG / Rij rats at experimentally caused sex hormone deficiency and on the background of exogenous injection of 17β-estradiol in combination with progesterone into ovariectomized female rats are presented for the first time. The obtained new data on the morphofunctional features of the anterior cortical nucleus of the amygdaloid body of the brain significantly expand the notion of reactive changes in the anterior cortical nucleus at different levels of sex hormones and can be used by researchers of various profiles in studying this structure of the brain. The monograph is intended for neurobiologists of various specialities (neuromorphologists, neurophysiologists, neuroendocrinologists, neurochemists, etc.) engaged in the research of the amygdaloid body and the limbic system of the brain.

Naloxone reverses post-ejaculatory inhibition of sexual behaviour in female rats

1987 ◽  
Vol 113 (3) ◽  
pp. 429-434 ◽  
Author(s):  
G. Forsberg ◽  
I. Bednar ◽  
P. Eneroth ◽  
P. Södersten
Keyword(s):  
Sexual Behaviour ◽  
Opioid Peptide ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Sexual Receptivity ◽  
Peptide Receptor ◽  
Oestradiol Benzoate ◽  
Brain And Spinal Cord ◽  
The Brain

ABSTRACT Sexual receptivity was inhibited in ovariectomized rats treated with oestradiol benzoate (OB: two injections of 2 μg) and progesterone (0·5 mg) immediately after ejaculation by the male and restored after the end of the post-ejaculatory refractory period in the male. The post-ejaculatory inhibition of sexual receptivity was reversed by i.p. (5 mg), intracerebroventricular (50 μg) or intrathecal (50 μg) injection of the opioid peptide receptor antagonist naloxone. The concentration of serum β-endorphin-like immunoreactivity in ovariectomized rats treated with OB plus progesterone was unaltered by sexual interactions with males (18·3 ± 6·0 (s.e.m.), 26·4 ± 2·1 and 21·8 ± 6·1 pmol/l before sexual activity, after ejaculation and after the end of the post-ejaculatory interval) but reduced to non-detectable by hypophysectomy. Subcutaneous injection of 10 μg β-endorphin raised serum concentrations of β-endorphin-like immunoreactivity but did not affect the display of sexual behaviour. The behaviour was also unaffected by intracerebroventricular injection of 0·1, 0·2 or 1·0 μg β-endorphin or by injections of 0·25 μg β-endorphin in the periaqueductal central grey of the mesencephalon. The results show that ejaculation by male rats causes a transient inhibition of sexual receptivity in the female which may be dependent upon opioid peptide receptor mechanisms in the brain and spinal cord. It is unlikely that the peptide is β-endorphin. J. Endocr. (1987) 113, 429–434

scholarly journals Total DNA methylation in the brain in response to decitabine treatment in female rats

2019 ◽  
Vol 66 (1) ◽  
pp. 1-3
Author(s):  
L. Balagova ◽  
K. Buzgoova ◽  
P. Karailiev ◽  
D. Jezova
Keyword(s):  
Dna Methylation ◽  
Anticancer Drugs ◽  
Brain Regions ◽  
Female Rats ◽  
Male Rats ◽  
Antidepressant Effects ◽  
Total Dna ◽  
Aberrant Dna Methylation ◽  
The Brain ◽  
Scarce Data

Abstract Hypomethylating agent decitabine is being used in the treatment of certain types of leukaemia in combination with other anticancer drugs. Aberrant DNA methylation has been suggested to occur in pathological states including depression. Scarce data in male rats suggest antidepressant effects of decitabine. The main aim of our studies is to test the hypothesis that the inhibition of DNA methylation results in antidepressant effects in female rats. Before doing so, we decided to verify the effects of decitabine on DNA methylation in females. The findings demonstrate that the treatment with decitabine at the dose shown previously to inhibit DNA methylation in males, had no effect on total DNA methylation in two brain regions, namely the hippocampus and frontal cortex of female rats. In conclusion, the present study allows us to suggest that the effect of decitabine on DNA methylation in the brain is sex dependent.

Cyclic and diurnal alterations in the response of luteinizing hormone and prolactin to prostaglandin E2 during the rat oestrous cycle

1984 ◽  
Vol 106 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Lise Wogensen ◽  
Jørgen Warberg
Keyword(s):  
Luteinizing Hormone ◽  
Prostaglandin E2 ◽  
Lateral Ventricle ◽  
Mature Female ◽  
Oestrous Cycle ◽  
Female Rats ◽  
Male Rats ◽  
Prostaglandin E ◽  
The Brain ◽  
Time Of Administration

Abstract. Two μg of prostaglandin E2 (PGE2) was infused into a lateral ventricle of the brain of female rats at 09.00 or 13.00 h on the different days of the oestrous cycle and the effect on luteinizing hormone (LH) and prolactin (Prl) release was determined. At 09.00 h PGE2 caused a pronounced release of LH in pro-oestrous, oestrous and metoestrous rats whereas the LH response in dioestrous rats was moderate. The secretion of Prl was only stimulated in rats from the pro-oestrous phase. When infused at 13.00 h PGE2 had a marked stimulatory effect on the release of LH in all groups of rats. The response was almost the same in oestrous, metoestrous and dioestrous rats but pro-oestrous rats a 2-fold higher LH response was observed. On each day of the oestrous cycle it was found that the LH-releasing activity of PGE2 was greater at 13.00 h than at 09.00 h. Thus, the overall greatest responsiveness of LH to PGE2 was noted at 13.00 h on pro-oestrus i.e. at a time which was prior to the onset of the spontaneous LH surge. At 13.00 h – as at 09.00 h – PGE2 was only capable of stimulating Prl release in pro-oestrous rats. Resembling the LH response it was found that PGE2-induced Prl release was greater at 13.00 h than at 09.00 h. In adult male rats the stimulatory effect of PGE2 on LH and Prl release was independent of the time of administration. It is concluded that the neuroendocrine elements of the hypothalamo-pituitary unit in mature female rats exhibit cyclic as well as diurnal alterations in the responsiveness to PGE2.

scholarly journals Postnatal development of growth hormone and prolactin cells in male and female rat pituitary. An immunocytochemical light and electron microscopic study.

1987 ◽  
Vol 35 (3) ◽  
pp. 335-341 ◽  
Author(s):  
G Smets ◽  
B Velkeniers ◽  
E Finne ◽  
A Baldys ◽  
W Gepts ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Cell Types ◽  
Female Rats ◽  
Male Rats ◽  
Intermediate Lobe ◽  
Female Rat ◽  
Electron Microscopic ◽  
Adult Rats ◽  
Gh Cells ◽  
Immature Rats

Localization and ultrastructural maturation of prolactin (PRL) and growth hormone (GH) cells were studied in pituitaries from neonatal, immature (4-6 weeks old), and adult rats (2-3 months old) by light and electron microscopic immunocytochemistry. The distribution pattern of these cells did not change with age. Both cell types were concentrated laterodorsally, with PRL cells adjacent to the intermediate lobe and GH cells nearer the center of the pars distalis. Labeling density of the immunogold reaction was highest for both hormones in immature rats. In neonatal and immature rats, one PRL cell type with granules 200 nm in diameter was present. In adult rats, two types of PRL cells were present: one containing polymorphous granules measuring about 500 nm (prevalent in female rats), the other with spherical granules about 200 nm (prevalent in male rats). No changes were detected in GH cells during maturation.

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