Biomedical subjects

S Darbra

Publications and source records attributed to S Darbra.

4 recordsLinked to original sources

PubMed1995

Perinatal alterations of thyroid hormones and behaviour in adult rats.

Several studies have shown the relevance of the neuroendocrinological system in the development and function of the nervous system. In order to observe the influence of thyroid hormones during development on the behaviour of adult rats we induced dysthyroid states during the perinatal period. Results indicate that some behaviours are more susceptible to the action of thyroid hormones than others. We observed that the thyroid hormone deficiency causes an increase of activity in animals in spite of a large period of rehabilitation. Thyroxine-treated rats showed an anxiogenic behavioural pattern in the elevated plus-maze, while animals rehabilitated from perinatal deficit of thyroid hormones showed an anxiolitic pattern. These findings suggest that an excess of thyroid hormones has less effect on behaviour than a deficiency of these hormones.

Aging↗

PubMed1993

Is prolactin related to activity and emotional reactivity in rats?

Recent studies have shown different relationships between hormones and personality in humans, including a relationship between prolactin levels and impulsivity. The aim of the present work was to study the relationships between basal levels of prolactin and some measures of activity and emotional reactivity in rats. One of the most consistent results showed a negative correlation between basal prolactin levels and activity. This finding is in line with the serotonergic theories of impulsive behavior and with the effects of dopamine upon activity.

Animals↗

PubMedDate not supplied

Immediate and delayed voluntary ethanol effects on motor performance, learning and inhibition in rats.

The effects of prolonged voluntary ethanol consumption on psychomotor performance, operant conditioning and inhibition were examined in adult male Wistar rats. Animals were food deprived and alcohol or control solution was available 1 h/day during 15 days, with free water for the rest of the day. Then, rats were tested in a two-bottle paradigm (solution and water available) for 1 h/day during 19 days, and subjects were tested daily for psychomotor performance and operant conditioning immediately or 6 h after (delayed) the solution access. Psychomotor performance was tested in an 80 degrees -inclined screen. Successive conditioning phases were: free shaping (FS), continuous reinforcement (CRF), operant extinction (EXT), successive discrimination (DIS) and two-stimuli test (TST). Alcohol consumption deteriorated psychomotor performance and improved the animal's ability to learn simple associations between stimuli and responses (free shaping and extinction), in immediate and delayed groups. Finally, alcohol deteriorated behavioral inhibition (DIS and TST) tested immediately after drinking. Taken together, results suggest that prolonged voluntary ethanol intake could induce permanent psychomotor impairment and associative learning facilitation, and also an impairment of the inhibition related to the intoxication state.

Alcohol Drinking↗

PubMedDate not supplied

[Hormones and aggression].

This work is a review about psychoendocrinologic aspects of aggressive behavior. We have considered two approaches, the classical view focused on hormonal influences in the regulation of aggression and the most recent view which accounts for the influences of aggressive behavior and social status on hormonal secretion. In this review we differentiate the organizational from the activational effects. The main conclusions are referred to the gonadal steroids effects both organization and activation of the neural subtract of aggression. Among them it seems that aromatizable androgens have the most important effects. On the other hand, the testosterone would be predictive for dominant social status, the corticosterone would be for submission and finally, the ACTH would be predictive for the aggressive behavior but not for submission. In addition to that the literature point that the defeat experience is the main factor in submission. Referred to the effects of behavior on hormonal secretions, all the studies point out that social interaction elicits sympathetic-medullar and gonadal activation in the dominant animals and cortico-adrenal activation in the submissive ones.

Adrenocorticotropic Hormone↗