Norman Adler

If female rats received genital stimulation soon enough after their male partners had ejaculated, sperm transport and subsequent pregnancy were inhibited. Manual stimulation by the experimenter or five intromissions by a male rat were sufficient stimuli to reduce the number of sperm found in the uterus and to reduce the number of uterine implantation sites.

... It has been pro-posed that hippocampal theta rhythm is associated with the orienting reflex (Grastyan, Lissak, Madarasz, & Donhoffer, 1959), goal-directed behavior (Adey, Dun-lop, & Hendrix, 1960), motivated behavior ... RUTH GROOME KURTZ AND NORMAN T. ADLER r^^ ...

Female rats drink more 3% NaCl solution than do males, both when they need sodium (need-induced sodium intake or sodium appetite) and when they do not (need-free sodium intake). The sexual dimorphism of sodium intake is a secondary sexual characteristic because after castration at 1 day of age male rats drank 3% NaCl in adulthood in a manner similar to that of females in both the need-free and need-induced state, and females given long-term, neonatal testosterone drank low, malelike volumes of 3% NaCl on a daily need-free basis, but their response to sodium depletion was unchanged. This sexual dimorphism of sodium intake seems to be governed by testosterone that has been converted in the brain to estrogen because treatment of Day 1 castrated females with a nonaromatizable androgen, dihydrotestosterone, did not change either their need-free or their need-induced 3% NaCl intake. Castration in adulthood of male and female rats did not change their sodium consumption. However, when castrated adults received testosterone, need-free intakes of NaCl were suppressed in both sexes, but the suppression of 3% NaCl intake occurred only while the steroid was present. Exogenous testosterone also lowered the need-induced sodium intake of adult castrated females. Thus, in castrated adults, need-free intake was actively suppressed by exogenous testosterone in both sexes, whereas need-induced intake of NaCl was suppressed only in females. These data indicate that sodium intake in the rat is a sexually dimorphic behavior that is organized neonatally and can be actively suppressed in adulthood by testosterone.

Six experiments were performed to investigate the effects of the rat's copulatory behavior on sperm transport in the female's reproductive tract. Data showed that (a) transcervical sperm transport in rats requires 6--10 min after ejaculation for completion; (b) transcervical transport of large numbers of sperm requires that the vaginal plug remain lodged tightly in the vaginal-cervical junction; (c) maintenance of an immobile posture by the male, and possibly by the female, at ejaculation facilitates the deposition of a tightly lodged vaginal plug and the transport of large numbers of sperm through the cervix; (d) a single intromission occurring within 2 min after ejaculation disrupts sperm transport, but more copulatory stimulation is required to disrupt sperm transport when delivered between 4 and 10 min after ejaculation; and (e) the average postejaculatory interval is long enough to prevent a male from disrupting the transport of most of his own sperm from the preceding ejaculation.

68 M. К. MCCLINTOCK & NT ADLER of the female is to respond to the male's initiation. While the female may occasionally approach or attract the male (Barnett, 1963; Larsson, 1956; Dewsbury, 1967; Clemens, 1975; Madlafousek, et al., 1976), the descrip-tion of the ...

Examined in 8 experiments the copulatory behavior of male Sprague-Dawley rats for their role in initiating successful pregnancy in female Sprague-Dawley rats. Major effects were: (1) stimulation derived from the multiple intromissions delivered during 1 ejaculatory series induced the hormonal conditions prerequisite to ovum implantation and successful pregnancy, and (2) intromissions facilitated sperm transport through the cervix. Without at least 1 intromission before ejaculation, the sperm did not pass from the vagina into the uterus. Results are analyzed with reference to the functional relationship between patterns of copulation in male rodents and the length of estrous cycles in females. (36 ref.)

Abstract 1. 6sexually experienced male rats of the S 1 strain copulated under 2 experimental and 2 control conditions. Experimental conditions consisted of placing lidocaine anesthetic on the male's penis either just before exposure to a female or during his 1st post-...