[The significance of the rabbit's septum as a relay station between the midbrain and the hippocampus. I. The control of hippocampus arousal activity by the septum cells].

Role of ventrolateral medulla in vasomotor regulation: a correlative anatomical and physiological study

The responses of ovarian oocytes obtained from mature frogs (Rana pipiens) to pituitary hormone were examined after removal of the follicular envelope. When the follicular envelope was removed manually or after treatment with collagenase, the apparently naked oocyte can still respond to pituitary hormone by germinal vesicle breakdown and by polar body formation. However, when the follicular envelope was removed after treatment with EDTA or Ca-Mg-free solution, the responsiveness of the oocyte was completely lost. Microscopic examination revealed that removal of the follicular cells was incomplete unless Ca-Mg-free solutions or EDTA were used. Complete removal of follicle cells prevents the oocyte from responding to pituitary hormone.



Moreover, the naked oocytes packed together with previously separated follicular envelopes showed maturation responses when treated with pituitary hormone solution in the presence of large amounts of ovarian tissue. Naked oocytes which are unable to respond to pituitary hormone can nevertheless full respond to progesterone to undergo maturation reactions. In fact, germinal vesicle berakdown and polar body formation were brought about within intact ovarian tissue by treatment with progesterone alone. Oocytes responding to progesterone alone always remained within the follicular envelope.



The degree of maturation of the oocytes after progesterone treatment was tested by means of nuclear transplantation. When nuclei obtained from blastula or early gastrula cells were implanted into treated oocytes, still within the follicular envelope, normal cleavage occurred. These results indicate that pituitary gonadotropin acts on the follicle cells to stimulate them to release a hormone that directly acts on the oocyte to induce maturation.

Relative roles of the pituitary, follicle cells, and progesterone in the induction of oocyte maturation in Rana pipiens

A comparative study of the role of the cerebral arterial blood in the regulation of brain temperature in five mammals

Expression of fos-like protein in brain following sustained hypertension and hypotension in conscious rabbits

The rabbit diencephalon in stereotaxic coordinates.

A study of the effects of progesterone on ovulation in the rabbit reveals that the steroid at first facilitates and subsequently inhibits the release of pituitary ovulating hormone. Forty estrous or estrogen-primed female rabbits were treated with 2 ing. progesterone in oil subcutaneously and subjected within 1–4 hours to glass-rod stimulation of the vagina; 11 of them ovulated as compared with only 2⁄30 controls. Mating or intravenous copper acetate, within 4 hours after injection of progesterone, stimulated ovulation in all of 10 estrous rabbits. A few progesterone-treated females ovulated “spontaneously.” The facilitation appeared to depend on synergism of progesterone with estrogen; 10 anestrous animals failed to respond to progesterone and vaginal stimulation by ovulating. Twenty-four hours after treatment with progesterone, 21 initially estrous or estrogen-primed rabbits were allowed to mate; only 14 would permit copulation and 10 of these failed to ovulate. None of 10 estrogen-progesterone-treated ...

Stimulatory and inhibitory effects of progesterone on the release of pituitary ovulating hormone in the rabbit.

SummaryThe results indicate that the nervous-pituitary-ovarian conditions of the estrous cat may be simulated by estrogen-PMS priming, and that cats in such artificial estrus may be employed as favorable material in experimental studies on nervous control of the adenohypohysis.

John W. Everett

Papers

The rabbit diencephalon in stereotaxic coordinates.

Stimulatory and inhibitory effects of progesterone on the release of pituitary ovulating hormone in the rabbit.

Priming the Anestrous Gat for Reflex Discharge of Pituitary Ovulating Hormone.