Effects of adrenalectomy on brain weight, body weight and weight of certain endocrine organs in rats.

Albino rats, both males and females were adrenalectomized (Adx.), either on the eleventh or the twenty fifth day after birth and the body weights recorded daily until the sixtieth day when all the animals were sacrificed. Brain (cerebrum and cerebellum), pituitary, thyroid and gonads were weighed post mortem. Body weights decreased in all the Adx. animals, the decrease being statistically significant in the male rats Adx. on day 11 (p less than 0.05). Both cerebrum and cerebellum recorded a significant increase in weight in both the male Adx. groups, whereas pituitary, thyroid and gonads showed a significant decrease. Changes observed in 25 day Adx. female rats were not statistically significant. Thus, adrenalectomy in the young rats appears to have differential effects on the somatic, neural and endocrine growth.

Ingestive behaviour of starved rats after single intraperitoneal injection of fresh plasma from well-fed rats.

Ingestive behaviour of control and experimental rats following 96 hours of starvation was studied. The control animals were injected normal saline intraperitoneally (I.P.) whereas the experimental animals were injected I.P. with fresh plasma obtained from well fed rats. Having been presented with food 15 minutes after the injections, the food intake (Gms +/- SEM) of control animals for the first five hours after injection was 6.00 +/- 0.44, whereas, the intake in experimental animals for the same period was 0.55 +/- 0.05. The food intake was significantly suppressed for the next three days, attaining the normal values by the 4th day. Since all the rats were starved prior to injection, all of them increased in weight during the four days of study, but the increase seen in the experimental group was much subdued. Therefore the plasma factor, suppresses not only the food intake but also the gain in body weight.

Four-arm radial open maze (FAROM) as a tool for assessing the effect of atropine in spatial memory of the rats.

Place learning behaviour for working (short term) memory and reference (long term) memory is studied with the Four-arm radial open maze (FAROM) in 18 rats divided equally in three groups. In group I, 0.5 mg of atropine was injected intra-peritoneally 30 minutes before the trial. In group II, saline and in group III Glycopyrrolate were injected instead. Twenty three hours hungry animals were tested on each day in the maze to search for food kept in one of the eight cul-de-sacs of maze. The latency i.e. the time to reach the goal cul-de-sacs, as well as the error score i.e. the number of entries in the non-goal cul-de-sacs were counted during six consecutive trials, per day. Each trial duration was 5 minutes or the time taken by the animal to search the goal compartment whichever was less. The inter-trials period was 10 min and the work was carried out for a period of 3 weeks. The results show that atropine does block effectively both the memory faculties i.e. working and reference memory and that level of memory deficit induced by atropine is related to the rate of drug uptake by the central cholinergic receptors.