This Study was performed to evaluate the effect of atenolol on the serum concentration of TT4 and TT3 in subclinical hyperthyroid patients. Due to the i n s u fficient information about the effect of atenolol on serum level of these hormones, the aim of this research was to shade some light on the subject. Fifteen subclinical hyperthyroid patients entered this study. Each patient received ...

The suprachiasmatic nuclei (SCN) of the hypothalamus contain a pacemaker that generates circadian rhythms in many functions. Light is the most important stimulus that synchronizes the circadian pacemaker to the environmental cycle. In this paper we have characterized the baseline neuronal firing patterns of the SCN as well as their response to light in freely moving rats. Multiunit and single-u...

Magnetic compass orientation in a night-migratory songbird requires that Cluster N, a cluster of forebrain regions, is functional. Cluster N, which receives input from the eyes via the thalamofugal pathway, shows high neuronal activity in night-migrants performing magnetic compass-guided behaviour at night, whereas no activation is observed during the day, and covering up the birds' eyes strong...