Neuroendocrinological Studies on Anxiety Assessed by Frontal Midline Theta Activity

The distinct EEG theta rhythm from the frontal midline area during performance of mental tasks has been called Fmθ. It is suggested that anxiety is negatively associated with the appearance of Fmθ. In the present study, the relationship between anxiety level assessed by the appearance of Fmθ and neuroendocrinolgical function was investigated using male university students with (n=9) and without (n=9) Fm<9. Three endocrinological tests such as TRH test, L-Dopa test and DST were performed in all subjects. In the TRH test, blood samples were drawn at 15 min before and at 15 min, 30 min, 60 min, 90 min, 120 min, and 180 min after protirelin 3.5 mg injection. In the L-Dopa test, blood samples were obtained at 15 minbefore and at 15 min, 30 min, 60 min, 90 min, 120 min, and 180 min after levodopa 500 mg administration. In the DST, blood samples were drawn at 5 min before and at 9 hr, 17 hr, and 24 hr after dexamethasone 1 mg administration. The concentrations of serum TSH, PRL and GH in TRH test, of serum PRL and GH in the L-Dopa test, and of plasma cortinol, CRF and ACTH in the DST were measured. On the baseline values, only PRL concentration in the non-Fmθ group was greater than that in the Fmθ group. PRL values of the non-Fmθ group were lower than those of the Fmθ group in the L-Dopa test. However, there were no significant differences between the two groups in the TRH test and the DST. These results suggest that high anxious humans without Fmθ might show higher function of D_2 receptor activity as compared with low anxious persons with Fmθ.

不安

前頭正中部θリズム（Fmθ）

神経内分泌

薬物付加実験