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C K Wagner

Publications and source records attributed to C K Wagner.

26 records · Page 2Linked to original sources
PubMed1991

Projections of the paraventricular nucleus of the hypothalamus to the sexually dimorphic lumbosacral region of the spinal cord.

Lumbar regions L5-L6 of the spinal cord of the male rat contain the sexually dimorphic motor nuclei, the spinal nucleus of the bulbocavernosus (SNB) and the dorsolateral nucleus (DLN), which innervate perineal muscles, the bulbocavernosus and the ischiocavernosus, respectively. This neuromuscular system controls penile reflexes which are essential to male reproductive success. Oxytocin has been shown to induce penile reflexes and the site of action for these effects is the PVN. Since PVN is known to project to cervical and thoracic levels of spinal cord, the present study examined projections of the PVN to the L5-L6 region of the spinal cord. WGA-HRP was injected into the region of L5-L6, aimed at the SNB and DLN and their dendritic extents, in intact male, castrated male and female rats. WGA-HRP-labelled cells bodies were found in the parvocellular subnuclei of PVN, as well as regions of the lateral hypothalamus and the dorsal area of the hypothalamus. These results demonstrate that the PVN projects to lumbar levels of the spinal cord that are sexually dimorphic and androgen-dependent. This suggests that PVN may modulate the activity of these motoneurons.

Animals↗
PubMed1989

Anatomical organization of the sexually dimorphic perineal neuromuscular system in the house mouse.

The anatomy of the sexually dimorphic motoneuron nuclei of the bulbocavernosus (BC) and ischiocavernosus (IC) muscles, as well as the non-sexually dimorphic external and sphincter (EAS), was examined in hybrid B6D2F1 mice using the retrograde tracer, cholera toxin-bound horseradish peroxidase. Motoneurons innervating the BC were located in the dorsomedial nucleus (DM), as well as in the ventral nucleus (V) and in the mid-region of the ventral horn (MVH). Following injections restricted to the IC, labelled neurons were found in the dorsolateral nucleus (DL), as well as in V, DM and MVH. Cells innervating the EAS in both males and females were located in the DM, as well as in the V and MVH. An elaborate network of dendrites extended between all labelled nuclei. The present results demonstrate that the anatomical specificity of the sexually dimorphic neuromuscular system of the mouse differs from that observed in other species.

Animals↗
PubMed1989

Perinatal modification of a sexually dimorphic motor nucleus in the spinal cord of the B6D2F1 house mouse.

The sexually dimorphic dorsomedial nucleus (DM) of the spinal cord of mice is affected by gonadal steroids in adulthood and these effects are dependent upon genotype. Following castration of adult mice there is a decrease in DM cell size in DBA/2J and hybrid B6D2F1 strains and a decrease in the number of cells staining with thionin in C57B1/6J and B6D2F1 strains. The effects of androgens on development of the DM nucleus were examined in B6D2F1 mice, which exhibit both characteristics in adulthood. Testosterone propionate (TP) administered to females pre- or postnatally resulted in a significantly larger number of motoneurons in the region of the DM when compared to administration of the vehicle alone, while soma area remained unchanged. Adult males castrated on the day of birth had significantly fewer cells in the DM than did intact males. Differences in cell size between shams and castrates were dependent upon age.

Aging↗
PubMed1986

Prior intrauterine position influences body weight in male and female mice.

In two longitudinal studies, intrauterine location of male and female Rockland-Swiss mice relative to fetuses of the same and opposite sex dramatically influenced body weight. In one study, body weight of males and females that were located in utero between two female fetuses (OM animals) or between two male fetuses (2M animals) was assessed from birth to the time of weaning (25 days of age). The body weights of 2M females were indistinguishable from those of OM and 2M males on all but a few of the 25 postnatal days of life. Also, 2M females were significantly heavier than OM females from Postnatal Day 6 onward, and 2M males weighed significantly more than OM males from Postnatal Day 19 onward. In a second study, food intake and body weight of animals from different intrauterine locations were examined from 25 to 120 days of age. Regardless of prior intrauterine position, males were always heavier than females. However, prior in utero location modulated body weight in that 2M females were significantly heavier than OM females and 2M males were reliably heavier than OM males. Intrauterine position effects were observed in the absence of any appreciable influence of this variable on levels of food intake. Taken together, the results suggest that prior in utero location may influence metabolic set points involved in the regulation of body weight and fat storage.

Age Factors↗
PubMed1986

Mice: postpartum aggression is elevated following prenatal progesterone exposure.

Pregnant Rockland-Swiss (R-S) mice were injected with sesame oil or 250 or 500 micrograms of progesterone (P) on Days 12 through 16 of gestation and the postpartum aggressive behavior of their female offspring was examined in adulthood. Both doses of P significantly increased the intensity of aggression (number of attacks) exhibited by the female offspring toward an adult male intruder. The low dose of P also produced significant increases in relative anogenital distance. These effects were seen in the absence of any effects on body weight at birth or in adulthood, or on reproductive performance. The findings support previous research, in both animals and humans, showing that prenatal brain differentiation and subsequent behavior are masculinized by prenatal exposure to progesterone.

Aggression↗