Sex differences in benzodiazepine binding in the frontal cortex and amygdala of the rat 24 hours after restraint stress.

Marked sex differences have been reported in behavioural responses of rats 24 h after exposure to a brief period of restraint (RT) stress. In the present study, differences in benzodiazepine (BZ) binding between male and female rat litter-mates randomly allocated to control or RT groups were investigated 24 h after RT. Scatchard analysis, using [3H] flunitrazepam, was carried out on the the frontal cortex and amygdala.

Formalin-induced changes in adrenocorticotropic hormone and corticosterone plasma levels and hippocampal choline acetyltransferase activity in male and female rats.

Formalin (10%) induces higher levels of licking and flexing in female than in male rats, as shown in the present study. In order to ascertain the neural and hormonal modifications that accompany these behavioural differences, we determined the activity of choline acetyltransferase in the hippocampus and the levels of adrenocorticotropic hormone and corticosterone in the plasma. Two concentrations of formalin were used (50 microliters; 0.

Differential effects of restraint and novelty on the social behaviour of female rats.

In a previous work, we have described an increase of agonistic behaviour 24 h after a single 30-min restraint (RT) in female rats. The present work was aimed at assessing whether this effect was actually due to physical immobilization or was a mere consequence of the exposure to a novel environment (the restraining box in the experimental room). Dioestrous females were either left undisturbed in their home cages (Control), restrained (RT), or subjected to the same experimental schedule as the restrained ones, but placed in a living cage instead of in the restraining device (Novelty).

Sex-related effects on behaviour and beta-endorphin of different intensities of formalin pain in rats.

The effects of two intensities of formalin pain on behaviour and beta-Endorphin (beta-EP) concentration in the brain and pituitary were studied in male and female rats. The animals were familiarized with the Hole-Board apparatus for 3 days, and then, after a subcutaneous injection of formalin (50 microliter, 0.1 or 10%) or Sham-injection (Control) in the hindpaw, they were tested in the Hole-Board for 60 min.

Behavioural effects of different intensities of formalin pain in rats.

The effects of two concentrations of formalin (0.1% and 10%) on Licking, Flexing and Paw-Jerk, and standard measures of activity, were studied in male rats during three experimental conditions: Box, Open-Field and Novel Object. Pain-evoked responses were present in all formalin-injected animals, with greater intensity in the group injected with formalin 10%.