Reproduction and population structure of the sea urchin Heliocidaris crassispina in its newly extended range: The Oga Peninsula in the Sea of Japan, northeastern Japan.

Ocean warming has facilitated the range expansion of commercially important sea urchin species to higher latitudes. Heliocidaris crassispina was recorded to extend northward to Toga Bay along the Oga Peninsula, Japan following an increase in seawater temperatures, and replacement of local sea urchin species Mesocentrotus nudus. In order to identify evidence of adaptation occurring in response to a range extension of H.

The ventromedial hypothalamus oxytocin induces locomotor behavior regulated by estrogen.

Our previous studies demonstrated that excitation of neurons in the rat ventromedial hypothalamus (VMH) induced locomotor activity. An oxytocin receptor (Oxtr) exists in the VMH and plays a role in regulating sexual behavior. However, the role of Oxtr in the VMH in locomotor activity is not clear.

Rat uterine oxytocin receptor and estrogen receptor α and β mRNA levels are regulated by estrogen through multiple estrogen receptors.

Estrogen action is mediated through several types of receptors (ERs), such as ERα, ERβ and putative membrane ERs. Oxytocin receptor (OTR) and ER expression levels in the rat uterus are regulated by estrogen; however, which types of ERs are involved has not been elucidated. This study examined OTR, ERα and ERβ levels in ovariectomized rats treated with 17β-estradiol (E2), an ERα agonist (PPT), an ERβ agonist (DPN) or estren (Es).

Leptin resistance does not induce hyperphagia in the rat.

Leptin has been thought to work as a mediator for body weight control by inhibiting food intake. Leptin, however, cannot prevent obesity induced by a high-fat diet (HFD) probably because of leptin resistance. We investigated daily feeding and weight gain when ordinary chow (OC) was changed to a HFD in male rats.

Dietary deficiency of essential amino acids rapidly induces cessation of the rat estrous cycle.

Reproductive functions are regulated by the sophisticated coordination between the neuronal and endocrine systems and are sustained by a proper nutritional environment. Female reproductive function is vulnerable to effects from dietary restrictions, suggesting a transient adaptation that prioritizes individual survival over reproduction until a possible future opportunity for satiation. This adaptation could also partially explain the existence of amenorrhea in women with anorexia nervosa.

Estrogen Increases c-Fos expression in the paraventricular nucleus along with its anorexic effect in developing rats.

Estrogen inhibits food intake in cycling females in a variety of species. To determine how the development of the anorexic system by estrogen is regulated, rat pups at four developmental stages, postnatal day 11 (P11)-13, P20-22, P25-27 and P29-31, and adult ovariectomized (OVX) rats received a daily subcutaneous injection of 20 µg/kg of estradiol benzoate (EB) or vehicle for three days. Food intake, body weight gain and immunohistochemical c-Fos expression in the brain were measured after each injection.

Changes in uterine receptor mRNAs for oxytocin and estrogen in the pseudopregnant rat.

This study examined the uterine oxytocin- (OTR) and estrogen- (ER) receptor mRNA levels during and after pseudopregnancy (PSP) in rats. An increased OTR mRNA level was observed from day 14 of PSP, and the maximal level was attained during the following proestrus. The levels of ERalpha mRNA were low during PSP and significantly increased during the following estrus.

Prolactin releasing peptides modulate background firing rate and milk-ejection related burst of oxytocin cells in the supraoptic nucleus.

The hypothalamic dorsomedial nucleus is suggested to be a final relay site for the afferent pathway of milk-ejection reflex. Existence of prolactin releasing peptide-immunoreactive cells in the dorsomedial nucleus and synaptic contact of prolactin releasing peptide-immunoreactive terminals with oxytocin cells was reported. Experiments were done to test the effect of prolactin releasing peptide on the electrical activity of oxytocin cells in the supraoptic nucleus.

Variation in the expression of orexin and orexin receptors in the rat hypothalamus during the estrous cycle, pregnancy, parturition, and lactation.

The widespread distribution of mRNA encoding orexin- 1 (OX1R) and -2 receptors (OX2R) in the central nervous system suggests that orexin may be involved in multiple functional pathways. Central administration of orexin stimulates feeding and also affects ovarian steroid-dependent luteinizing hormone secretion, suggesting involvement of orexin in the regulation of reproductive function. To investigate a possible role for orexin in reproductive function, we examined variations in prepro-OX, OX1R, and OX2R mRNA levels in the female rat hypothalamus during the estrous cycle, pregnancy, parturition, and lactation using competitive reverse transcription-polymerase chain reaction.

Differential regulation of estrogen receptor alpha and beta mRNAs in the rat uterus during pregnancy and labor: possible involvement of estrogen receptors in oxytocin receptor regulation.

Oxytocin receptor (OTR) mRNA levels in the uterus dramatically increase in the near term human and rat. Estrogen is believed to be a potent stimulator of OTR mRNA expression. However, estrogen does not stimulate rat OTR mRNA expression on day 18 of pregnancy or in progesterone-treated rats.

Changes of receptor mRNAs for oxytocin and estrogen during the estrous cycle in rat uterus.

Oxytocin receptor (OTR) mRNA levels increase dramatically near term and is potently stimulated by estrogen because increased OTR mRNA levels result from estrogen treatment in ovariectomized rat uterus. In this study, OTR, estrogen receptor (ER) alpha and ERbeta mRNA levels in the rat uterus during the estrous cycle were examined by quantitative RT-PCR. OTR mRNA levels during the estrous cycle began to increase on diestrus (P<0.

Leptin affects the electrical activity of neurones in the hypothalamic supraoptic nucleus.

The present experiments were undertaken to examine whether leptin affects the electrical activity of neurones in the supraoptic nucleus (SON) by using brain slice preparation of male Wistar and obese Zucker rats. Bath application of leptin (10(-8) - 10(-12) M) induced mainly inhibitory response in SON neurones of Wistar rats, although a minority showed excitation. These effects were observed in both continuously and phasically active cells.