Influence of sexual activity on longevity in adult male Drosophilia melanogaster]

Ageing in Drosophilia is modified according to their physiological state. Adult longevity is decreased by sexual activity: in both sexes the life span of virgins is higher. For the same physiological state male longevity is always lower than that of females.     

Influence of social experience on sexual readiness of male house crickets,Acheta domestica

Summary MaleAcheta domestica were deprived of social experience at three different life stages and mated as 2-or 3-day adults. Those deprived from the egg stage were found to copulate morereadily than males which had social experience.The data were taken from a thesis submitted in partial fulfillment of the requirements for the Ph. D. degree at the City University of New York.     

Response of the starling circadian system to transitions between light and darkness

Summary The effects of exposure to sudden transitions from dark to light (D/L) and light to dark (L/D) were determined on the free running circadian feding rhythm of European stalings (Sturnus vulgaris). D/L transitions (step-up) produced phase advances throughout the circadian cycle. In contrast L/D transitions (step-down) produced both advances and delays. The L/D transition phase-response curve has a contour and shape similar to the phase-response curves previously obtained in birds with light pulses.     

Effect of light and darkness on the hypothalamo-neurohypophyseal system of the garden lizard,Calotes versicolor

Résumé Nous avons étudié l'effet d'une l'illumination continue ou d'une obscurité de 7 jours sur le système hypothalamique neurosécréteur (HNS) du lézard des jardinsCalotes versicolor. L'illumination a stimulé le HNS par activation de la synthèse, du transport et de la libération de la neurohormone(s) tandis que l'obscurité a fait diminuer la quantité libérée de neurohormone de la pars nervosa.     

Influence of the caudate nucleus on hippocampal afterdischarges in the rabbit

Résumé La stimulation du noyau caudé augmente et prolonge la postdécharge hippocampale chez le lapin.     

Influence of light on the plasma gonadotropin concentrations in the newborn rat

Summary The physiological increase in plasma gonadotropin (LH and FSH) levels in newborn rats is indisputably influenced by light. Permanent illumination accentuates this increase, whereas darkness decreases it in 16-day-old female rats. In male rats of the same age, only permanent illumination was tested with the same results.Acknowledgments. We would like to thank Dr C. Kordon (Unité de Neurobiologie, INSERM, rue d'Alésia, F-75014 Paris) who welcomed us in his laboratory and advised us on these experiments.     

Effect of continuous light on the blood and urinary sugar levels in alloxan diabetic rats

Summary Continuous light decreases the rise in blood glucose and the excretion of urinary glucose, along with increased urine volume, in alloxan diabetic rats.Acknowledgment. The authors' thanks are due to Prof. A. K. Maiti, Department of Physiology, Calcutta University for his constant encouragement.     

Asymmetric distribution of male and female foetuses in the pregnant rabbit uterus

Summary The sex distribution of foetuses in the uterine horn of the pregnant rabbit was found to be asymmetrical, with more males being present in the left uterine horn and more females in the right (p<0.05).     

Influence of light on the plasma gonadotropin concentrations in the newborn rat.

The physiological increase in plasma gonadotropin (LH and FSH) levels in newborn rats is indisputably influenced by light. Permanent illumination accentuates this increase, whereas darkness decreases it in 16-day-old female rats. In male rats of the same age, only permanent illumination was tested with the same results.     

Influence of melatonin,constant light,or blinding on reproductive system of gerbils (Meriones unguiculatus)

Summary Male and female gerbils were implanted s.c. with a pellet containing 2 mg melatonin/23 mg beeswax every 2 weeks for a total of 3 implants. A significant depression of ovarian and uterine weight was noted in female gerbils receiving melatonin implants. In the melatonin-treated male gerbils, growth of the accessory organs was significantly inhibited although testis size was not depressed.Supported by NSF grant No. BMS-74-06276 and Population Council grant No. M 74.87.     

Influence of side position on hippocampal afterdischarge (HAD) in the rabbit

Résumé Chez le lapin, la postdécharge hippocampique, provoquée par la stimulation maximale unilatérale de l'hippocampe, est inhibée par l'excitation du saccule ipsilatéral, mais elle est augmentée par l'excitation sacculaire contralatérale si l'hippocampe est stimulé avec une intensité submaximale.     

Comparison of the effects of different isomers of bicuculline infused in the preoptic area on male rat sexual behavior

Intracerebral infusion of (+) bicuculline methiodide, but not of its (-) isomer, in the preoptic area, stimulated masculine sexual behavior in rat as evidenced by a decrease in the number of intromissions preceding ejaculation and a shortening of the ejaculation latency and postejaculatory interval. Data suggest a role of the GABAergic system in mediating masculine sexual behavior.     

Seasonal variations in the sexual activity of the male genet (Genetta genetta L.)]

The Genet testis shows a spermatogenic activity throughout the year. The plasmatic androgen level presents two periods where the values are higher; one in spring the other in autumn. The spring testosterone rise co?ncides with a mating period.     

Androgen levels in the rete testis fluid during sexual development

Summary The concentrations of testosterone (T) and 5-dihydrotestosterone were measured in fluid collected from the rete testis of immature and adult rats. The results indicate that adult levels of T are attained in the seminiferous tubules much earlier than in the peripheral circulation.This work was performed at the Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts, USA and supported by the National Institutes of Health through grants HD12641 and HD12642. We thank Dr B.V. Caldwell for antiserum to testosterone.