Biomedical subjects

Maria Assumpció Martí-Carbonell

Publications and source records attributed to Maria Assumpció Martí-Carbonell.

4 recordsLinked to original sources

PubMed2004

Perinatal hypothyroidism effects on step-through passive avoidance task in rats.

Previous studies have documented a decrease in the ability of neonatal hypothyroid animals to learn and habituate to maze tests, and an increase in spontaneous activity. However, there is little information about the effects of perinatal (i.e., prenatal and postnatal) hypothyroidism on behaviour. The present study was designed to assess whether perinatal hypothyroidism in rats induces alteration on acquisition and/or short- and long-term retention of a learned response in male Wistar rats. Perinatal hypothyroidism was induced by prolonged (E9-P21) exposure of pregnant and lactating dams to methimazole (administered orally in drinking water, 0.2 mg/ml). Cognitive function was tested at 50 days by means of a step-through passive avoidance task. The effects of perinatal hypothyroidism on the retention of the passive avoidance response are long lasting being, however, highly dependent on the retention after the original training. Our results showed that methimazole-treated rats performed more poorly when retention was tested at long-term (24 h and 7 days) retention interval. Instead, methimazole-treated rats showed longer retrieval latencies than the control ones did when retention was tested at short term (1 h).

Animals↗

PubMed2003

Perinatal hypothyroidism effects on neuromotor competence, novelty-directed exploratory and anxiety-related behaviour and learning in rats.

Thyroid hormone is essential for proper development of the mammalian CNS. Previous studies have documented a decrease in the ability of neonatal hypothyroid animals to learn and to habituate to maze tests and an increase in spontaneous activity. However, there is little information about the effects of perinatal (i.e. perinatal and postnatal) hypothyroidism on behaviour. The aim of the present work was to investigate the longitudinal effects of perinatal hypothyroidism on certain aspects of the behaviour in rats. Neuromotor competence was tested at 21, 40 and 60 days, novelty-directed exploratory behaviour and anxiety-related behaviour were evaluated at 40 and 60 days by means of the Boissier tests and associative learning ability was tested at 80 days by means of a step-through passive avoidance task. The persistence of the effects of perinatal hypothyroidism on psychomotor performance was highly dependent on the task examined. Perinatal hypothyroidism caused an increase of locomotor activity as revealed by the total distance travelled in the Boissier test and this increase also comprised a component of decreased anxiety-related behaviour. Methimazole-treated subjects also had higher head-dip scores than controls at 40 days while no differences were observed at 60 days. Finally, our results showed that methimazole-treated rats performed poorly in a passive avoidance learning task.

Animals↗

PubMed2002

Effects of chronic dysthyroidism on activity and exploration.

The aim of the present study was to determine the influence of thyroid function on the activity and exploratory behaviour of male Wistar rats. Dysthyroidism was induced by adding drugs to their drinking water from the ninth day of gestation. This method is not as stressful as daily thyroxine injections or thyroidectomy, and therefore did not affect the analysed behavioural patterns. After weaning, the drugs were administered to the young rats until the end of the experiment. Activity and exploration were measured using the Boissier test, a light-darkness test and an open-field test when they were 77 days old. In order to verify that the animals' motor capacity had not been impaired, a psychomotor battery was used. Chronic hyperthyroidism produced a significant increase in activity, but did not affect exploration. On the other hand, hypothyroidism did not affect activity, but did increase exploration. This increase in exploration was observed in activity-independent behavioural parameters, such as head dipping and glancing.

Animals↗

PubMed2002

Effects of dysthyroidism in plus maze and social interaction tests.

The aim of the present study was to determine the influence of thyroid hormones on the anxiety of male Wistar rats. Dysthyroidism was induced by adding 20 mg of methimazole (100 ml) to their drinking water or by adding 0.3 mg of L-thyroxine (100 ml) to their drinking water from the ninth day of gestation. After weaning, the drugs were administered to young rats until the end of the experiment. Anxious behavior was measured using the elevated plus maze and social interaction tests when the animals were 85 days old. Chronic methimazole administration produced a significant anxiolytic pattern in both tests. In the plus maze test, the methimazole-treated animals entered and remained more time in the open arms than the control animals. In the social interaction test, they spent more time in bodily contact, and did this more frequently than those in the control group did. Results from this experiment suggest that chronic thyroid deficiency produces an anxiolytic-like effect in both tests.

Animals↗