Differential response to cholinergic stimulation in psychogenetically selected rat lines

Male and female rats of two lines psychogenetically selected for bipolar extremes in shuttle box avoidance were evaluated for tremor, salivation, chromodacryorrhea, and hypothermia following treatment with the muscarinic cholinergic agonist oxotremorine. Roman Low-Avoidance (RLA/Verh) rats exhibited more pronounced oxotremorine-induced tremor, chromodacryorrhea, and hypothermia than Roman High-Avoidance (RHA/Verh) rats. There was a sex difference only for the chromodacryorrhea response, with femles exhibiting a greater response following oxotremorine than males. In a subsequent experiment using female rats of both rat lines, it was demonstrated that pretreatment with the cholinergic antagonist scopolamine blocked oxotremorine-induced tremor, salivation and chromodacryorrhea responses in both rat lines and reduced the hypothermic effect observed in RLA/Verh rats (but not the much weaker hypothermia found in RHA/Verh rats) after oxotremorine injection. Pretreatment with the peripherally active cholinergic antagonist methscopolamine significantly reduced oxotremorine-induced salivation and chromodacryorrhea and somewhat decreased tremor and hypothermic responses in both rat lines. These results stand in contrast to the results of earlier research in which RHA/Verh rats exhibited greater behavioral depression in a tunnel maze than RLA/Verh rats following cholinergic manipulations. In view of evidence that these rat lines do not differ in number of muscarinic brain receptors, the present results may be due to genetic differences in other aspects of cholinergic neurotransmitter function, differences in the function of other neurochemical systems, or differences in the absorption, distribution, or metabolism of oxotremorine.     

Women and men exhibit different cortical activation patterns during mental rotation tasks

The strongest sex differences on any cognitive task, favoring men, are found for tasks that require the mental rotation of three-dimensional objects. A number of studies have explored functional brain activation during mental rotation tasks, and sex differences have been noted in some. However, in these studies there was a substantial confounding factor because male and female subjects differed in overall performance levels. In contrast, our functional brain activation study examined cortical activation patterns for males and females who did not differ in overall level of performance on three mental rotation tasks. This allowed us to eliminate any confounding influences of overall performance levels. Women exhibited significant bilateral activations in the intraparietal sulcus (IPS) and the superior and inferior parietal lobule, as well as in the inferior temporal gyrus (ITG) and the premotor areas. Men showed significant activation in the right parieto-occitpital sulcus (POS), the left intraparietal sulcus and the left superior parietal lobule (SPL). Both men and women showed activation of the premotor areas but men also showed an additional significant activation of the left motor cortex. No significant activation was found in the inferior temporal gyrus. Our results suggest that there are genuine between-sex differences in cerebral activation patterns during mental rotation activities even when performances are similar. Such differences suggest that the sexes use different strategies in solving mental rotation tasks.     

Fertility in Persons with Epilepsy: 1935–1974

Data from the Rochester-Olmsted County Medical Records Linkage Project were utilized to assess fertility in persons with epilepsy. Population age-specific reproduction rates for Rochester residents for the years 1935-1974 were estimated using the number of live births from the Minnesota Department of Health Statistics and Vital Statistics of the U.S. for comparison with rates in affected persons. Overall, fertility rates were significantly reduced to 80% of expected for affected males and 85% for affected females. Individuals with partial seizures (simple and complex) were disadvantaged, whereas those with generalized onset were not. During the last 20 years of the study period, males were more disadvantaged than females. The male-female difference was greatest during the time of low population fertility (after 1965). Male deficits were more marked after diagnosis; female deficits were more marked before diagnosis. Differences in the proportion of ever-married person-years between the sexes only partially explain the observed differences.     

Prenatal exposure to morphine alters brain μ opioid receptor characteristics in rats

Prenatal morphine exposure alters neither the binding capacity nor the affinity of ligand binding to μ opioid receptors of adult male brains. However, males have significantly higherB_max in the hypothalamus than ovariectomized females. In females, prenatal exposure to morphine reduces theB_max of μ opioid receptors 25% in the hypothalamus and preoptic area. Estrogen treatment increases theB_max of μ opioid receptors in the striatum of all ovariectomized females but in the hypothalamus only of morphine-exposed females, thereby eliminating the sex difference observed in control animals.     

Prolonged treatment with 8-hydroxy-2-(di-n-propylamino)tetralin (8-OHDPAT) differently affects the serotonergic modulation of cortical acetylcholine release in male and female guinea pigs

Acetylcholine (ACh) release from the cerebral cortex was studied in freely moving guinea pigs, implanted with epidural cups. A single dose of either 8-hydroxy-2-(di-n-propylamino)tetralin (8-OHDPAT, 0.1 mg/kg s.c.) or 5-hydroxytryptamine (5-HT, 250 μg i.c.v.) increased cortical ACh release, both in male and in female guinea pigs. In female guinea pigs chronically treated with 8-OHDPAT (0.1 mg/kg daily s.c., for 14 days) the facilitatory effect of 8-OHDPAT and 5-HT was maintained. In chronically 8-OHDPAT-treated male guinea pigs, 8-OHDPAT no longer modified ACh release, while 5-HT inhibited it. The inhibition was prevented by the 5-HT₃ antagonist MDL 72222, 1 mg/kg s.c. These results indicate that differences exist between male and female guinea pigs in the adaptive responses to prolonged treatment with the selective 5-HT_1A agonist 8-OHDPAT.     

The ameliorating effects of vitamin E on hepatic antioxidant system and xenobiotic-metabolizing enzymes in fenvalerate-exposed iodine-deficient rats

This study investigated the effects of vitamin E (VE) on hepatic antioxidant system and drug-metabolizing enzymes in fenvalerate (FEN)-exposed iodine-deficient (ID) Wistar rats. ID was produced by perchlorate containing drinking water. VE was introduced by a loading dose of 100?mg/kg/d, i.g. for the first three days in the last week of feeding period; then with a single maintenance dose of 40?mg/kg on the 4th day. During last week, FEN groups (F) received 100?mg/kg/d, i.p. FEN. VE alone did not significantly affect thyroid hormones and antioxidant parameters; however, significantly increased total cytochrome P450 (38%) and cytochrome b5 levels (36%). In all ID groups, plasma thyroid-stimulating hormone (TSH) levels increased markedly, but remained at control level in vitamin E plus FEN receiving iodine-deficient group (IDVF) group. Glutathione peroxidase activity showed marked increases in F (19%) and FEN-exposed iodine-deficient group (IDF, 48%) groups. FEN treatment significantly increased total cytochrome P450 (28%) and thiobarbituric acid reactive substance levels (36%), as well as 7-ethoxyresorufin O-deethylase (120%), 7-penthoxyresorufin O-deethylase (139%) and glutathione S-transferase (15%) activities and decreased total glutathione concentrations (28%) versus control. Overall results suggest that vitamin E has ameliorating effects on the measured parameters in ID and/or FEN exposure.     

Common and differential brain responses in men and women to nonverbal emotional vocalizations by the same and opposite sex

Nonverbal emotional vocalizations are one of the most elementary ways of communicating in humans. We examined the impact of sex differences on neural responses to laughter and crying produced by the same and opposite sex. Thirty subjects (15 women) underwent functional magnetic resonance imaging during a sex identification task for laughter, crying, and neutral voices. The parahippocampal gyrus was involved in both men and women while hearing laughter of the same sex, suggesting greater positive emotional processing and greater attention toward emotional context in response to laughter of the same sex than of the opposite sex. The posterior cingulate was involved in both men and women while hearing crying of the opposite sex, suggesting that empathic processing may occur more in response to crying of the opposite sex than of the same sex. Furthermore, brain responses to crying of the opposite sex seem to reflect upon men's efforts to perform emotional regulation and women's empathic concerns.     

缺氧对男性肺心病患者急性发作期下丘脑-垂体-性腺轴功能变化的影响

本文应用放免法检测了50例急性发作期男性肺心病患者及26名正常健康男性之血浆睾酮(T)、雌二醇(E_2)、血清黄体生成激素(LH)、卵泡刺激素(FSH)水平及对黄体生成激素释放激素(LRH)刺激的反应性。结果表明,急性发作期血浆T值明显降低(P<0.01),E_2/T比值显著升高(P<0.01);缓解期二者均恢复至对照水平。急性发作期患者对LRH刺激之反应亦有所减退。血浆E_2、血清LH和FSH水平均无明显变化。患者血浆T值与PaO_2呈明显正相关,E_2/T比值与PaO_2,呈明显负相关,T值、E_2/T比值与PaCO_2均无相关关系。作者提出:缺氧是导致男性肺心病患者急性发作期下丘脑-垂体-性腺轴功能改变的重要影响因素。     

Integration of tissue-specific inhibitors and thyroid hormones in regulation of epithelial cell proliferation in gastric glands

Department of Medical Biology and Genetics, Lugansk Medical Institute. Laboratory of Cell Biology, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR Yu. A. Romanov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 112, No. 7, pp. 94–96, July, 1991.