PubMed Health⌕ Search

Biomedical subjects

R J Barfield

Publications and source records attributed to R J Barfield.

89 records · Page 5Linked to original sources
PubMed1977

Ejaculatory and postejaculatory behavior of male and female rats: effects of sex hormones and electric shock.

Ejaculatory patterns were observed in normally reared, postpuberally castrated male and female rats treated with sex hormones and electrical shock in adulthood. In a preliminary experiment, 3 females treated with 50 microgram estradiol benzoate (EB) and 500 microgram progesterone (P) showed intromission and ejaculatory behavior when subjected to shock. Refractory periods were abnormally short and there was almost no postejaculatory vocalization. In Experiment 1, males and females were tested with electrical shock following daily treatment with 32 microgram EB with and without 500 microgram P on the test day. There was no difference between males and females in preejaculatory behavior, but females displayed abbreviated refractory periods and no postejaculatory vocalization. Progesterone had no observed effect. In Experiment 2 castrated males and females were subjected to shock after treatment with 8 microgram EB per day for 3 weeks. No P was given. Again females showed drastically reduced refractory periods and little vocalization. In Experiment 3, males and females treated with TP and shock displayed ejaculatory patterns, normal refractory periods and vocalization. Results show that female rats are capable of exhibiting the ejaculatory response without sex hormone treatment in perinatal life or androgen treatment in adulthood. It was also demonstrated that there is a sex difference in the postejaculatory behavior shown by estrogen-treated male and female rats.

Animals↗
PubMed1975

Sexual behavior: Extreme reduction of postejaculatory refractory period by midbrain lesions in male rats.

The refractory period that characteristically follows ejaculation was abolished or significantly reduced by rostral midbrain lesions in male rats. The postejaculatory vocalization was also abolished or reduced, but other aspects of copulatory performance were unaffected. The results were attributed to disruption of biogenic amine pathways that pass from the ventral part of the rostral midbrain into the posterior hypothalamus.

Animals↗
PubMed1975

Post-ejaculatory vocalization in castrated rats treated with various steroids.

Five groups of rats were observed for sexual behavior as intact subjects and in the 3 weeks following castration. Particular emphasis was placed upon ultrasonic vocalization recorded during the refractory period (RP) following ejaculation. All rats received daily injections (100 mug test steroid + 100 mug dihydrotestosterone propionate, DHTP) from the day of castration. Treatment groups were: Testosterone propionate (TP) + DHTP, N = 5; 19-hydroxytestosterone propionate (19HTP) + DHTP, N = 6; Oestradiol dipropionate (OP) + DHTP, N = 5; DHTP (200 mug/day), N = 6; Vehicle only, N = 7. Ejaculation and normal RPs were maintained with TP, 19HTP and OP treatments. In rats treated with DHTP alone or vehicle only ejaculatory ability declined and RPs increased in length. Ultrasonic vocalization was normal in all rats except those treated with OP, where it was either reduced or absent. In Week 4 treatments in TP + DHTP and OP + DHTP groups were reversed. During Weeks 5-7 vocalization was gradually restored in rats that previously received OP and partially inhibited in animals previously treated with TP. These results indicate that; (1) vocalization may not be dependent on the presence of testicular androgens and, (2) OP has a gradual inhibitory effect on vocalization when given at high doses and this effect is reversible.

Animals↗
PubMed1975

The ultrasonic postejaculatory vocalization and the postejaculatory refractory period of the male rat.

After ejaculation, the male rat emits an ultrasonic (22-kHz.) vocalization. This sound is produced repeatedly until about three fourths of the postejaculatory interval has elapsed. In this study, the occurrence of the vocalization was described, and physiological and behavioral evidence was presented that the postejaculatory vocalization reflects an inhibitory state that underlies the postejaculatory refractory period. The vocalization period was characterized by a predominance of slow-wave, spindling, sleep-like electroencephalographic activity. Electrical shock was able to stimulate mating responses only after the cessation of the vocalization period. It was concluded that an absolute refractory period of the postejaculatory interval lasts until the end of the vocalization period and that the time from the termination of the vocalization until the resumption of mating is a relative refractory period.

Animals↗
PubMed1975

Differential rates of exhaustion and recovery of several parameters of male rat sexual behavior.

Sexual exhaustion of the male rat was studied with respect to several copulatory measures. The ejaculatory latency, intercopulatory interval, and intromission frequency demonstrate a U-shaped curve, exhibiting high values for the initial ejaculatory series, falling to a minimum at an intermediate ejaculatory series, and again increasing at exhaustion. The absolute refractory period of the postejaculatory interval (measured at vocalization termination) increases linerly, whereas the relative refractory period (the remaining portion of the postejaculatory interval) is a postively accelerating function. Partial recovery tests demonstrated that the preejaculatory measures and absolute refractory period have substantially returned to baseline values by Day 6, while the relative refractory period is still extended. The significance of these data to the theoretical modeling of sexual behavior is discussed.

Animals↗
PubMed1973

Sexual behavior: normal male patterning in androgenized female rats.

Female rats treated with testosterone as neonates and as adults exhibited a temporal patterning of male copulatory behavior identical to that of normal males, although such females displayed few intromission reflexes and almost no ejaculatory patterns. With prenatal, postnatal, and adult testosterone treatment, female rats displayed all the characteristic masculine responses and intervals, including the ultrasonic postejaculatory vocalization.

Animals↗
PubMed1972

Sexual behavior: ultrasonic postejaculatory song of the male rat.

During the refractory period that follows ejaculation, the male rat regularly emits 22-kilohertz vocalizations. These cease after about three-fourths of the total period has elapsed, and this corresponds to an "absolute refractory period" during which the male cannot spontaneously initiate copulation. Similar 22-kilohertz vocalizations occur in other social contexts, and in general they appear to be desist-contact signals.

Animals↗
PubMed1968

Sexual behavior: stimulation by painful electrical shock to skin in male rats.

A mildly painful electric shock lasting 0.5 second was delivered every 30 seconds to the skin of male rats while they were with a receptive female rat. Sexual behavior occurred, with brief latency, after shocks; thus, successive shocks resulted in a pacing of sexual behavior. This effect is attributed to periodic augmentation of sexual arousal by a periodic, nonspecific arousing stimulus (that is, shock).

Animals↗