Effect Of Copulation Research Articles

TO STAY OR NOT TO STAY: DECISION-MAKING DURING TERRITORIAL BEHAVIOUR OFCALOPTERYX HAEMORRHOIDALISANDCALOPTERYX SPLENDENS SPLENDENS(ZYGOPTERA: CALOPTERYGIDAE)

Abstract The effect of copulation and presence of predators on territorial behaviour of male Calopteryx haemorrhoidalis (in southern France) and of male C. splendens splendens (in northern Germany) was studied in nature. A male obtaining a copulation early in the day often secured more copulations later that day than did males not obtaining an early copulation. Predators such as Green frogs, Rana esculenta, and water spiders, Dolomedes sp., affected subsequent behaviour of male Calopteryx that they attacked but failed to catch. A male C. haemorrhoidalis that had only recently occupied a territory when attacked by a spider, vacated the territory immediately, whereas a male first attacked after having occupied a territory for more than three hours and that had already courted females there remained, while avoiding the predator's immediate location. Results are discussed in the context of the value of the territory as a resource.

The facilitative influence of experiential factors on the parental behavior of male mice (Mus musculus): (i) The effects of the experience of copulation and cohabitation with a pregnant female

Effects of the experience of copulation and cohabitation with a pregnant female on male parental behavior were examined in ICR-strain male mice. The experience of copulation and/or cohabitation with a pregnant female promoted parental behavior, although the cohabitation with a pregnant female per se failed to inhibit infanticide in male mice. Therefore, it is possible that the facilitation of parental behavior is caused by a motivation independent from that of the inhibition of infanticide in male mice. As to the facilitation of parental behavior, the effect of copulation was stronger than that of cohabitation with a pregnant female, and these 2 effects seem to be additive. It is possible that there are 2 independent mechanisms for the facilitation of parental behavior in male mice.

Copulatory analgesia in male rats ensues from arousal, motor activity, and genital stimulation: Blockage by manipulation and restraint

The effect of copulation on the vocalization threshold to tail shock (VTTS) was assessed in freely-moving, sexually experienced, Wistar male rats. Mean VTTS during the first copulation was 40% above the baseline values and slightly decreased during the first postejaculatory interval (PEI; 28% above baseline). VTTS mean values further increased during the second copulatory series (93% above baseline and 63% during the PEI). Testing at the same intervals in noncopulating rats did not induce analgesia. VTTS values also increased after the display of either one ejaculation (E), five intromissions (I), or five mounts (M), the analgesia persisting for at least 20 min. Analgesia following M was smaller and shorter than that observed after either I or E. Analgesia developed gradually during copulation since VTTS values after five I were significantly higher than those after one I. The incidence of vocalizations to suprathreshold shocks (STS, 20% above the VTTS) occurring during various phases of copulation was also studied to determine the onset and short-term fluctuations of copulatory analgesia. The proportion of STS inducing vocalizations decreased from 91% (mean of individual proportions) before copulation, to 24% during copulation, and to 25% during the PEI. A maximal reduction in the proportion of vocalizations to STS was found during the last third of copulation. Nearly all vocalizations to STS during copulation occurred when subjects were quiescent, while few or no vocalizations occurred when rats were engaged in sexual activity, i.e., during M, I, or penile grooming. In contrast to the above-mentioned data, no significant analgesia was observed using the tail-flick latency test (TFL) following either E, five I, or five M. However, in the same subjects, only a transient, nonsignificant analgesia was observed following E or five I in the VTTS test. This last result suggests that the handling, restraint, or removal from the arena, required for the TFL measurements, antagonized the expression of copulatory analgesia. Results show that genital stimulation, arising from the performance of either I or penile grooming, provokes a gradually increasing analgesia that persists following E for at least 20 min.

Reinforcing properties of ejaculation in the male rat: Role of opioids and dopamine.

Ejaculation-induced reward in the male rat was evaluated by the conditioned place-preference paradigm. It was supposed that ejaculation induces a reward state such that it can be conditioned to environmental stimuli. Males were allowed to ejaculate once and were then immediately transferred to a place-preference cage. One ejaculation produced place preference. Naloxone (16 mg/kg) not only blocked this place preference but also induced a place aversion. Naloxone by itself had no effect on place preference. It is suggested that release of endogenous opioids renders ejaculation rewarding. Pimozide, in a dose of 1 mg/kg, had no effect on ejaculation-induced reward. Dopamine thus seems to be of slight importance for that effect of copulation. Perhaps compulsive sexual activity obeys the same mechanisms as compulsive drug use in opiate addicts.

Statistical analysis of frequencies and proportions of cytologically classified spermatogenic cells in the hermaphroditic snailLymnaea stagnalis.2. Effects of copulation

Summary Effects of copulation on spermatogenesis in the hermaphroditic snail Lymnaea stagnalis were studied in both male and female copulants by studying the levels of the frequencies of the four spermatogenic stages distinguished. Heterogeneity was found within the group of males before copulation and within the group of females 2 h after copulation. For stages I and II, there was no significant effect of copulation, and interaction of copulation and the male or female role during copulation could not be demonstrated. However, the interaction between these factors appeared to be significant for both stages III and IV. The effects on these latter stages are supposed to be exerted by humoral factors mediated by the Sertoli cells.

Effect of copulation on the hypothalamic content of gonadotrophic hormone-releasing hormone in the vole, Microtus agrestis.

There was a drop of 56% in the hypothalamic content of Gn-RH in female voles 5 min after mating compared with that in unmated but receptive animals. This suggests that the surge of LH in vole plasma associated with reflex ovulation is evoked by a massive release of Gn-RH.

The effect of copulation on the plasma antidiuretic activity of the male rat.

The plasma antidiuretic activity and the content of antidiuretic hormone (ADH) and oxytocin of the neurointermediate lobe were determined in male rats under normal conditions and after copulation. The plasma samples from control rats assayed directly in the water-loaded ethanol-anaesthetized rat had no detectable antidiuretic activity. The same negative result was observed in plasma obtained from male rats during courtship. However, plasma obtained from male rats at different time intervals after copulation had an antidiuretic activity which was maximal one h after ejaculation. When the ADH was extracted from pools of plasma samples, the circulating level of the hormone in control rats was also measured. The plasma antidiuretic activity after copulation was abolished after thioglycolate treatment which inactivates the neurohypophysial hormones. These findings suggest that ADH is released after copulation and that such a release is maintained for at lest 60 min.

Secretion in the rat coagulating gland (anterior prostate) after copulation.

The effect of copulation on the rat coagulating gland (anterior prostate) was studied. At 4 to 6 h after the beginning of copulation the coagulating glands of rats that had produced copulatory plugs were nearly empty of secretion. Ultrastructurally, the coagulating gland has large cisternae of rough endoplasmic reticulum (RER) and few condensing vacuoles or secretion granules. After copulation the number of secretion granules and the frequency of their expulsion into the lumen increased. Also in the lumen were "fragmentation" vesicles (50-100 nm diameter) that were bounded by a unit membrane and appeared to arise from microvilli. At 4, 6, and 7h after the beginning of copulation there was an increase in apical blebbing. Blebbing was found in both perfusion and immersion-fixed tissue. Also, after copulation there was an increase in "light cells" that were characterized by reduced RER cisternae, an electron lucent cytoplasm, and atrophic Golgi apparatus. The luminal ground substance, secretion granules, and some Golgi elements, contained polysaccharides as seen with the periodic acid-thiocarbohydrazide-silver proteinate method.

Failure of Copulation to Affect Serum Prolactin, LH, and Estrogen Levels in Female Rhesus Monkeys

SummarySerum concentrations of pro-lactin, LH, and estradiol-17β (E2) were measured on Day 1 (Day 8-17 of the menstrual cycle) at 30 and 0 min before and 10, 30, 60, 120, and 180 min after coitus in five intact female rhesus monkeys. Blood samples were also collected on a similar schedule on the following 2 days when the females were placed for 30 min in the mating cage alone (Day 2) or in the presence of a male in a separate cage (Day 3). None of the females showed an increase in serum prolactin or E2 levels on any of the 3 days. Serum LH levels increased (P < 0.05) in two of the three monkeys in which they were monitored. However, of these two monkeys, one showed a similar LH increase when she was left alone in the mating cage. In three females which refused copulation, serum prolactin, LH, and E2 levels remained unchanged.The effect of copulation on serum LH was further investigated in eight additional females which were allowed to copulate on Days 5, 12, and 22 of the menstrual cycle and in two long-t...

5α-Androstenone and Testosterone in Peripheral Plasma of the Boar During and Following Copulation

Copulation was generally followed by increases in peripheral plasma 5α-androstenone and testosterone levels lasting for periods of about 60 to 100 min. The effect of copulation on the plasma levels of these steroids did, however, vary between boars. In seven out of eight boars the maximum levels of 5α-andro-stenone in the period 60 to 100 min. after copulation were from 114 to 218 % (mean 150 %) of the levels in samples collected before copulation. The corresponding figures for testosterone were from 104 to 283 % (mean 190 %). One boar showed decreasing plasma steroid levels after copulation. The coefficient of correlation between the peripheral plasma levels of 5α-androstenone and testosterone was found to be + 0.61 (n = 2.03).

Synthesis and secretion of glycoproteins in rat bulbo-urethral (Cowper's) glands. 1. The effect of copulation on the glandular content and on the incorporation of galactose and leucine.

Discharge and synthesis of rat bulbo-urethal gland secretory product was studied in relation to the normal copulatory process. Measurements of the macromolecularly-bound hexose contents in the glands revealed that immediately after the start of sexual intercourse, the glands emitted secretory product independently of the occurrence of ejaculation. Depletion of the glands was completed after 4 h (64 percent loss of hexose contents), concurrently with an ending of mating. The glands refilled gradually with hexose until after 1 week hexose contents had returned to the control level. In vivo labeling of the secretory product with ‘4 C-leucine and H-galactose at various time intervals after the start of copulation showed that glycoprotein synthesis increased immediately and peaked 6 and 13 h, After about 4 days, synthesis was again near the control level. These trends were accompanied by impressive morphological alterations. In control glands the lumen was filled with secretory product and the cells were studded with secretory granules and contained only scarce cytoplasm. Within 4 h after the start of the intromissions the glandular lumen was empty and the development of cell structures indicated active formation of secretory

The control of sexual receptivity in female Drosophila

1. 1. This paper describes various experiments on the integration of reproductive physiology and behaviour in female Drosophila melanogaster and D. simulans. 2. 2. The sexual behaviour of females is ascribed to two distinct processes. One determines the state of receptivity, i.e. whether a female is ‘accessible’ to stimulation from the courtship of a male, the other summates the various stimuli from courtship and eventually leads to the female accepting a male. 3. 3. Females are unreceptive to males on the day of eclosion (day 0) about 25 per cent are receptive on day 1, the rest by day 2. More precise tests place the transition period between 24 and 40 hr from eclosion. In any individual the change is a sudden one; females are either fully receptive or fully unreceptive. Accordingly this change is called ‘switch-on’. 4. 4. The corpus allatum and ovaries show a growth cycle parallel to that of receptivity. Evidence is presented that increase in juvenile hormone titre is responsible for the ‘switch-on’ of receptivity. 5. 5. Virgin females remain receptive for many days, but an increasing proportion become unreceptive after the first week of adult life. ‘Switch-off’ like ‘switch-on’ is a rapid, all-or-nothing process. Females also become unreceptive immediately after mating and this inhibition of receptivity has two components, (a) an effect of copulation itself, probably mechanical, which wears off after 48 hr, (b) an effect due to the presence of live sperm, which wears off once a female has exhausted the sperm by egg laying, after some 8 to 10 days. 6. 6. Old females which have mated and used up their sperm are more often receptive than virgins of the same age. It is suggested that this is so because their corpora allata are more active and the juvenile hormone concentration is kept up above the critical level for longer. 7. 7. The situation revealed in Drosophila is compared with that found in other insects, particularly with regard to the role of the endocrine system.

Effect of copulation on the release of pituitary gonadotropins in male and female rats.

The effect of copulation on the release of pituitary LH and FSH was studied in male and female rats. Plasma LH significantly increased 5-10 min post coitum in both sexes and remained high during the first hour. After 2 hr values dropped to normal levels. Also, in spayed rats pretreated with estrogen-progesterone an increase in plasma LH was found. Pituitary LH concentration 1 hr after copulation showed a decrease of more than 50% as compared with the controls, but after 4 hr no difference was detected. Ovarian ascorbic acid depletion, indicative of endogenous liberation of LH, was observed 1 hr post coitum. A slight but not significant increase in pituitary FSH concentration was found 1 hr after coitus in male and female rats and a significant increase was observed in males at 4 hr. No changes in plasma FSH were detected. Vaginal stimulation with a glass rod in the proestrous or estrous rat did not induce changes in ovarian ascorbic acid concentration nor in pituitary LH and FSH content. (Endocrinology 79...

Influence of copulatory stimuli on uterine motility to transporte the sperm into uterus of the rat. I. Effect of copulation on eliciting pseudopregnancy and uterine motility

Influence of copulatory stimuli on uterine motility to transporte the sperm into uterus of the rat. I. Effect of copulation on eliciting pseudopregnancy and uterine motility

The Effects of Larval Population Density on Some Laboratory Characteristics of Anopheles quadrimaculatus Say

The demonstration of the role of mosquitoes as disease vectors provided the impetus for extensive studies of these insects as laboratory animals. Notwithstanding, there has been little progress toward what might be termed the standardization of the mosquito for laboratory purposes. In particular, there may be considerable variation in the biting characteristics and behavior of Anopheles quadrimaculatus, even under well controlled laboratory conditions. Since preliminary work indicated that larval development has specific effects on the adult mosquito, the present studies were undertaken in an attempt to define some of the intrinsic factors which affect the laboratory biology of A. quadrimaculatus. This report deals with the effects of two extremes of larval population densities on some morphological and physiological characteristics of this mosquito, and the effect of copulation on the avidity of the female for a blood meal.