Cognitive parameters and morning and evening types: two decades of research (1990-2009).

An important area of study has examined cognitive aspects of morningness-eveningness orientation. Optimal times of efficiency in participants classified as Morning and Evening types are of great importance for understanding their cognitive abilities. The present review covers the last two decades (1990-2009), during which the important review by Tankova, Adan, and Buela-Casal appeared, and focuses particularly on attention, memory, and executive functions.

Morning and evening personality characteristics in a sample of young Italians.

The goal of this study was to investigate associations of morning and evening personality types with personality dimensions in a convenient sample of 60 men and 60 women, ages 18 to 29 years. A short form of the Morningness-Eveningness Questionnaire and a personality questionnaire Come mi vedo (How I see myself), based on the 5-factor model of personality, were given. Several personality dimensions appear to be significantly correlated with Morningness scores: Conscientiousness (positively) and Openmindedness (negatively). The analysis indicated morning types tend to reach their goals resolutely and to plan their steps, they prefer to be precise, tidy, punctual, trustworthy; they have a sense of duty and responsibility; they are also less original and less open to culture and novelties, less curious, conformist, traditionalist, and less well-informed, hardworking, steady, tenacious, and diligent, on the Come mi vedo.

Contrasting effects of nitric oxide on food intake and GH secretion stimulated by a GH-releasing peptide.

OBJECTIVE: Among the many actions of nitric oxide (NO) are those on endocrine and feeding behaviour. Based on NO involvement in the GH-releasing effect of the GH-releasing peptides (GHRPs) and the reported orexigenic activity of these compounds, we sought to evaluate the effect of the combined administration of a long-acting NO donor, molsidomine, and the newly synthesized GHRP EP92632 on food intake and GH secretion in rats. Moreover, to verify the specificity of a potential NO involvement, we evaluated whether or not the effects of GHRPs were abolished by a pre-treatment with an inhibitor of NO synthase, N-nitro-arginine-methyl-ester (NAME). METHODS: In the food intake experiments, adult Sprague-Dawley male rats underwent acute administration of: (1) EP92632 (160 microg/kg, s.c.); (2) molsidomine (100 mg/kg, i.p.); (3) EP92632+molsidomine; (4) l-NAME (40 and 60 mg/kg, i.p.); (5) EP92632+l-NAME (60 mg/kg, i.p.); (6) EP92632+molsidomine+l-NAME (60 mg/kg, i.p.); and (7) 0.9% saline (0.1 ml/kg, i.p.). After treatments, the cumulative food intake in the 6 post-treatment hours was carefully evaluated. In the neuroendocrine experiments, rats were given the same compounds according to the above reported schedule, except for the use of one dose of NAME (60 mg/kg, i.p.) and a lower EP92632 dose (80 microg/kg, s.c.), and were sampled via atrial cannula. RESULTS: EP92632 significantly stimulated food intake, an effect which was further enhanced by molsidomine, though the latter did not elicit per se any orexigenic effect. l-NAME given alone significantly decreased food intake and abolished the orexigenic effect of the GHRP and the enhancing effect of molsidomine. Plasma GH levels increased significantly following administration of EP92632 but, in contrast to the food intake experiments, molsidomine significantly inhibited both basal and EP92632-stimulated GH secretion; moreover, NAME had a biphasic effect on the EP92632-stimulated GH release: initially inhibitory and then, from 45 min on, stimulatory. NAME did not affect basal GH levels but, surprisingly, combined administration of molsidomine and NAME induced a striking inhibition of both basal and the peptide-stimulated GH release. CONCLUSIONS: In summary, these data indicate that NO in the rat is physiologically involved in a stimulatory way in the GHRP-mediated effect on food intake, but exerts a dual action, probably stimulatory at hypothalamic and inhibitory at pituitary levels, on basal and GHRP-stimulated GH secretion.