Lynn Health Science Institute

Socialization is an adaptive behavior during the early stages of life because it helps young animals become independent and determines healthy adult social behavior. Therefore, it is probable that the brain areas involved in the processing of social stimuli are more sensitive to social novelty during early life stages. To test this hypothesis, four groups of young male rats were exposed to different socioenvironmental stimuli; nonsocial physical novelty, social familiarity, social novelty, and a control group which received no stimulation. After stimuli exposure, brains were fixed and cut in coronal sections for c-Fos immunohistochemistry. The number of c-Fos-immunoreactive (c-Fos-ir) neurons in the paraventricular nucleus and supraoptic nucleus, the main producers of oxytocin and vasopressin, was compared, as well as in the nucleus accumbens and ventral pallidum, the main areas involved in reinforced behavior. A significantly higher number of c-Fos-ir neurons were found in animals exposed to social novelty in all areas, except in the supraoptic nucleus. In particular, the increase in c-Fos-ir in the paraventricular nucleus seems to be selective in response to social novelty, while the increase of c-Fos-ir in the nucleus accumbens and ventral pallidum suggests that social novelty during youth is a highly rewarding stimulus compared with social familiarity and nonsocial physical novelty.

Poor sleep quality is associated with adverse health consequences. Sleep disturbances can impact the immune function and process of inflammation. The relationship between sleep quality and the inflammatory bowel disease (IBD) has not been well studied. A prospective observational cohort study was performed to assess the correlation of the quality of sleep and disease activity in IBD. We used the Pittsburgh Sleep Quality Index (PSQI) to measure sleep quality. IBD disease activity was measured by using the Harvey-Bradshaw Index or Modified Mayo Score. Forty-one patients were enrolled with mean age of 37 ± 15.4 years and 27 (66%) women. Abnormal PSQI was present in all 23 (100%) of the clinically active patients and in 13 (72%) of those with inactive disease (odds ratio = 2.8, P = 0.007). All 30 patients with histologic evidence of inflammation on recent ileocolonoscopy also had abnormal PSQI scores, which were independent of their clinical disease activity status. Only 6 of 11 patients with histologically quiescent disease had abnormal PSQI scores (odds ratio = 6.0, P < 0.0001). There was no difference in disease type, use of steroids, the presence of depression or anxiety, and body mass index between the patients with normal and abnormal sleep. An abnormal PSQI had a positive predictive value for histologic inflammatory activity of 83%. Our data show a strong association between clinically active IBD and poor sleep quality and demonstrate that patients in clinical remission with abnormal sleep have a high likelihood of subclinical disease activity.

Previous work has indicated that low temporal coherence of ultradian sleep EEG rhythms is characteristic of depressed patients and women in particular. It may also be evident in depressed children and adolescents, although most published studies are limited in sample size. The present study evaluated temporal coherence of sleep EEG rhythms in 173 children and adolescents 8-17 years of age, including 97 who met criteria for major depressive disorder (MDD) and were symptomatic but unmedicated at the time of study and 76 healthy controls. Temporal coherence of all-night sleep EEG rhythms was evaluated on the second of two nights in the laboratory. Data were coded for diagnostic group, gender and age and subjected to MANOVAs. Temporal coherence was significantly lower in adolescents with MDD, compared to healthy controls. Findings were most robust for coherence between left and right beta and between delta and beta in both hemispheres. Both gender and age strongly influenced between-group differences, with the lowest temporal coherence among MDD girls, even in those under 13 years of age. In conclusion, early onset depression is associated with a reduction in synchronization of sleep EEG rhythms that shows a differential maturational course in boys and girls.