Role of testosterone on pain threshold in rats.

Pain thresholds were recorded in rats by progressive increase in electrical stimulation to induce tail withdrawal, vocalisation and vocalisation after discharge. It was observed that castration resulted in significant reduction of pain threshold which however returned to normal level on substitution with testosterone therapy.

The rate and degree of food compensation on alteration of its caloric density in rats.

The ability to regulate energy level by male albino rats on administration of food with varying caloric densities, was studied. The animals fed different caloric density diets exhibited marked variations in their caloric in take in the initial stages which stabilized after 5 to 10 days and maintained on lower mean caloric intake on diet having density of 2.63 Kcal/gm, and higher mean caloric intake on diet with density of 4.

Effect of duration of stress on pain threshold in rats.

Rats were subjected to immobilization stress of varying duration and their pain thresholds were recorded. It was seen that stress of lesser duration did not affect the endogenous opioid analgesic system while stressor of longer duration stimulated this system to its maximum irrespective of further increasing the duration of the stress condition even upto two fold.

Effect of intensity and duration of stress on male sexual behaviour.

Male rats were exposed to four different stress conditions, varying in duration and intensity, during separate periods and their copulatory behaviour was studied. The number of mounts and time spent in other sexual behaviours were reduced with intensity of stressor being primarily responsible rather than prolongation of duration of a less severe stress condition.

Role of caudate nucleus on modulation of blood pressure responses in cat.

Changes in blood pressure, heart rate and respiration were studied in 15 cats on bilateral stimulation of rostral, middle and caudal regions of caudate nucleus. Hypotensive response was obtained on stimulation of anterior caudate nucleus, which changed to pressor response when posterior caudate nucleus was stimulated. Biphasic blood pressure responses were recorded on stimulation of middle caudatal area.