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S Segovia

Publications and source records attributed to S Segovia.

At least 55 records · Page 3Linked to original sources
PubMed1987

The bed nucleus of the stria terminalis in the rat: regional sex differences controlled by gonadal steroids early after birth.

The effects of postnatal (on day 1 (D1) after birth) male orchidectomy and female androgenization on the bed nucleus of the stria terminalis (BNST) were studied. The volume of the medial posterior region of the BNST was greater in the control males than in the control females. Postnatal treatment reversed these differences. Sex differences were also found in the medial anterior region of the BNST where female rats always showed a greater volume than did the males. Female androgenization on D1 did not affect the volume of the BNST medial anterior region. However, D1 male orchidectomy did increase significantly the volume of this region. No sex differences were found in lateral, ventral or intermediate BNST divisions.

Androgens↗
PubMed1986

Effects of early postnatal gonadal steroids on the successive conditional discrimination reversal learning in the rat.

In the present study the existence of sex differences in the acquisition, retraining and reversal of a successive conditional discrimination learning (Experiment 1) and the role of the early postnatal gonadal steroids on these discrimination tasks (Experiment 2) were investigated. In Experiment 1 two groups of experimentally naive rats (males and females) were exposed to a black-white successive conditional discrimination task in a T-maze. No sex differences were found in the acquisition or retraining. However, in the reversal phase females made fewer errors and reached the discrimination criterion (90% of correct choices) sooner than males. In Experiment 2, the absence of sex differences in the acquisition or retraining phases and the existence of sexual dimorphism in the reversal period were confirmed. In addition, female androgenization and male orchidectomy, on day one after birth, reversed the direction of the sex differences found in the successive conditional discrimination reversal learning.

Androgens↗
PubMed1986

Effects of sex steroids on the development of the accessory olfactory bulb mitral cells in the rat.

The effects of postnatal (on day 1 after birth) male castration and female androgenization on accessory olfactory bulb (AOB) mitral cells population were studied. Control males showed a greater number of AOB mitral cells than females. Postnatal treatments abolished and inverted these differences. It is suggested that the population of AOB mitral cells is influenced by sex steroids during at least a postnatal period.

Animals↗
PubMed1986

Effects of sex steroids on the development of two granule cell subpopulations in the rat accessory olfactory bulb.

The effects of postnatal male castration on day 1 (D1) after birth and female androgenization on accessory olfactory bulb (AOB) light and dark granule cell populations were studied. Control males showed a greater number of both light and dark AOB granule cells than females. Postnatal treatment reversed these differences in the light granule cells. Female androgenization on D1 does not affect the number of AOB dark granule cells. However, male orchidectomy also on D1 significantly decreases the number of dark granule cells. Androgens injected into female rats are able to increase the number of AOB dark granule cells if they are administered on D14. This suggests a different critical period for the early effects of androgens on the dark granule cells with respect to light granule cells.

Animals↗
PubMed1984

Effects of sex steroids on the development of the accessory olfactory bulb in the rat: a volumetric study.

The effects of postnatal (on day 1 after birth) male castration and female androgenization on accessory olfactory bulb (AOB) volume were studied. Control males showed greater values than females in AOB volume. Postnatal treatments abolished and inverted these differences. It is suggested that the AOB development is influenced by sex steroids during at least a postnatal period.

Animals↗
PubMed1984

Effects of postpuberal gonadectomy on the neurosensorial epithelium of the vomeronasal organ in the rat.

In the present report the effects of postpuberal gonadectomy on vomeronasal organ (VO) morphology were studied. Postpuberal gonadectomy induced in both male and female rats a decrement in the height of the epithelium and in the nuclear size of the bipolar neurons. These results show that the maintenance of neurosensorial normal morphology depend upon the activational effects of sex steroids.

Animals↗
PubMed1982

Sex differences in alpha-adrenergic receptors in the rat brain.

[3H]Dihydroergocryptine ([3H]DHE) binding to several brain regions was studied in male and female rats, the latter in two different endocrinological states (estrous and diestrous-1). males showed higher [3H]DHE binding than females in hypothalamus, hippocampus and olfactory bulb, while females showed higher levels than males in spinal cord and visual cortex. In addition, intra-sex (that is, estrous versus diestrous-1) differences were detected in the cervico-thoracic spinal cord and cerebellum. Diestrous females presented higher values in both regions.

Animals↗
PubMed1982

Effects of neonatal thyroidectomy on the development of the vomeronasal organ in the rat.

The effects of postnatal thyroidectomy (on day 8 after birth) and 131I treatment (on day 10) on the development of the vomeronasal organ (VO) has been studied In the rat. Thyroidectomized rats showed decrements in the overall VO volume, volume of the neurosensorial epithelium, neuronal population and nuclear size of neurons. These results in VO paralleled those reported in the central nervous system after thyroidectomy.

Aging↗
PubMed1982

Effects of sex steroids on the development of the vomeronasal organ in the rat.

In the present report the effects of postnatal (on day 1 after birth) male castration and female androgenization on vomeronasal organ (VO) development were studied. Control males showed greater values than females in VO volume and neurosensorial epithelium, while the opposite was true with respect to nuclear size. Postnatal treatments abolished these differences. It is suggested that the VO development is influenced by sexual hormones during at least a postnatal period as it occurs for several structures of the central nervous system connected with the VO.

Aging↗