Exploratory behavior, learning ability, and thyroid hormonal responses to stress in female rats rehabilitating from postnatal hypothyroidism.

Newborn female Long-Evans rats were divided into groups of normal, hypothyroid [0.1% propylthiouracil (PTU) a reversible antithyroid goitrogen in the litter's drinking water], and hypothyroid rehabilitated (PTU water from birth to day 25, normal water thereafter). The rats were tested for several adaptive behavioral tasks between 40 and 90 days of age.

Rehabilitation from neonatal hypothyroidism: spontaneous motor activity, exploratory behavior, avoidance learning and responses of pituitary--thyroid axis to stress in male rats.

Long-Evans male rats were made hypothyroid from birth by the addition of 6-N-propylthiouracil (PTU) to their drinking water (0.1%). A group of animals was rehabilitated beginning at postnatal day 25 by withdrawal of the PTU from the drinking water.

Circadian pattern of multiunit activity of the rat suprachiasmatic nucleus during the estrous cycle.

Multiunit activity (MUA) of the suprachiasmatic nucleus (SCN) of the hypothalamus and medial preoptic area (MPOA) was recorded in chronically implanted, freely moving female rats. The integrated MUA of the SCN and MPOA was significantly higher in the dark than in the light period of day. Superimposed upon this diurnal rhythmicity in the SCN were 3.

Suckling ability and maternal prolactin levels in hypothyroid rats.

Long-Evans rats and their offspring were made hypothyroid by addition of the antithyroid goitrogen 6-N-propylthiouracil (PTU) to the drinking water (0.1%) from the day of parturition. Serum concentrations of prolactin (PRL), thyroid-stimulating hormone (TSH) and thyroxine (T4) were determined by double radioimmunoassay (RIA).

Steroid anaesthesia: alphadione depresses multiunit activity in the mesencephalic reticular formation.

Cortical EEG and multiunit activity (MUA) of the mesencephalic reticular formation (MRF), area hypothalami anterior (AH) and the nucleus amygdalae basalis (AMY) were studied before and after different doses of alphadione (Althesin) and hexobarbitone (Evipan-Natrium) given to cats with chronically implanted electrodes. Non-anaesthetic doses of alphadione (0.15 ml/kg; 0.