The present study aimed to analyze the effects of neonatal stimulation on species-specific behaviors (defensive reactions to a predator and social interactions) in adult male and female rats. Handling and an unpredictable sequence of aversive stimuli were applied to male and female pups from the 1st to the 10th day after delivery; behavioral inhibition, aggression, and sexual behavior were evaluated in adulthood. Results showed that either neonatal handling or aversive stimulation decreased behavioral inhibition in a novel and potentially harmful situation (open field with a predator) in both male and female rats and increased maternal aggressive behavior. Sexual behavior in both males and females decreased, which could affect reproductive capability. The results could cast doubts on the generalization of beneficial effects of neonatal stimulation on the behavior of adult rats.

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These findings suggest cognitive differences among ADHD subtypes, supporting the diagnostic distinction among them. Adolescents with ADHD-HI do not seem to have significant cognitive deficits.

Both the lesion of the parvocellular region of the PVN (FIG. 1) and the acute reduction of OT synthesis in that nucleus (FIG. 2) increase maternal aggression in rats. Previous work showed that ibotenic acid as well as the OT antisense in the PVN reduced the level of OT in the brainstem, but not in the pituitary. Therefore, the oxytocinergic parvocellular neurons of the PVN appear to exert an inhibitory effect on the aggressive behavior of the lactating female rat against an adult intruder. In a relationship of a different nature, mother-infant, a facilitatory effect of OT has been shown. Previous work showed a significant decrease of OT mRNA levels in the PVN of female rats during the first 10 days after delivery compared to late pregnancy, which is the inverse ratio of the natural temporal evolution of maternal aggressive behavior. Furthermore, in the present work, a functional decrease of OT mRNA was probably the effect of the antisense in the PVN. In conclusion, OT cells in the PVN appear to play different roles on maternal care and maternal aggression.

Adrenocortical insufficiency is a serious complication of AIDS. Usually, integrity of the hypothalamo-pituitary-adrenal (HPA) axis in AIDS patients is assessed by measuring basal cortisol levels and cortisol response to 250 microg of ACTH. Recent studies suggest that a lower ACTH dose increases the sensitivity of the procedure. In the present study, we investigated the prevalence of adrenal hypofunction in AIDS patients using a low-dose ACTH test (1 microg), evaluated the clinical characteristics that might suggest this diagnosis, and the diseases and/or drugs that could be associated with it. We prospectively evaluated 63 very ill AIDS patients and 16 normal controls. A standard examination assessed the presence of signs and symptoms of adrenal insufficiency. Blood samples were collected before and 30 and 40 minutes after an injection of 1 microg 1-24 ACTH. No opportunistic disease, signs, symptoms or drugs were associated with an abnormal cortisol response to ACTH. The lowest stimulated cortisol level in the control group was 18.5 microg/dL; cortisol levels > or = 18 microg/dL were taken to indicate a normal HPA axis. Test results revealed that 12/63 AIDS patients (19%) had an abnormal HPA axis. With these data in mind, we suggest a prospective adrenal function evaluation of all severely ill AIDS patients.