With the purpose of correlating neuroendocrine and neurophysiological data, the effects of stimulating brain areas which have been shown to be involved in the mediation of adrenocortical reponses, i.e. pontine reticular formation (PRF), mammillary peduncle (MP), medial forebrain bundle (MFB), and the suprachiasmatic nucleus (SCN), were studied on unit activity in the mediobasal hypothalamus in the rat. About half of the units recorded responded significantly to one of these modalities by a change in the rate of firing, the MP producing mainly inhibition and SCN facilitation and changes also occurred in the post-stimulus histograms. There was a convergence of different modalities on the same hypothalamic unit. No changes occurred in the time-interval histograms. Stimulating the mediobasal hypothalamus activated synaptically units in the PRF, MP, and MFB but none of them were activated antidromically. The present data demonstrate electrophysiological connections between extrahypothalamic regions participating in adrenocortical regulation and the hypophysiotropic area of the hypothalamus.

Adrenocorticotropic Hormone↗

PubMedDate not supplied

Suprachiasmatic nucleus responsiveness to photic and basal hypothalamic stimulation.

In view of the demonstrated role of light and of the suprachiasmatic nucleus (SCN) in the maintenance of circadian rhythms related to endocrine functions and as the mediobasal hypothalamus (MBH) controls neuroendocrine activity, the effects of light and MBH stimulation on the electrical activity of SCN neurons were studied in rats. Out of 253 cells studied in the SCN, 32 cells were antidromically activated, while 65 cells responded orthodromically to MBH stimulation. In another series of experiments out of 95 suprachiasmatic neurons, 11 were antidromically activated by MBH stimulation and 18 different SCN cells responded to continuous light. The present data, which demonstrate photic responses in suprachiasmatic neurons and direct projections from the SCN to MBH, are discussed in view of the current knowledge on the role of the retinohypothalamic tract and the SCN in the control of circadian rhythms.

Animals↗

PubMedDate not supplied

Clinical effect of a triclosan-containing dentifrice on plaque and gingivitis: a six-month study.

A total of 294 adult male and female subjects completed a 6-month, double-blind clinical trial designed to evaluate the effects of a dentifrice which contained 0.3% triclosan in conjunction with 2% of a methoxyethylene/maleic acid copolymer in a 0.243% sodium fluoride/silica base, relative to a control dentifrice, on supragingival plaque accumulation and gingivitis. Plaque and gingivitis were scored after 3 and 6-month use of the assigned dentifrice. At the end of the study, the triclosan group showed an average reduction, relative to the control group, of 12% in plaque accumulation and 20% in gingivitis. Both were statistically significant at p < or = 0.0001. The effect of the triclosan dentifrice was most pronounced on the more severe manifestations of plaque and gingivitis. The improvement in the gingival parameters at 6-months relative to the control dentifrice was statistically significant at p < or = 0.0001. It was concluded that the twice-daily use of the triclosan-containing dentifrice resulted in significant reduction in supragingival plaque formation and a significant improvement in gingival health without the presence of any extrinsic staining or objectionable taste.

Adolescent↗

PubMedDate not supplied

Medical waste management regulations.

Explore the source record for details and available documents.

Hazardous Waste↗