태아알코올효과를 가진 흰쥐 솔기핵에서 serotonin함유 신경세포의 생후 발달에 미치는 thyroxine의 효과

Abstract

Serotonin(5-hydroxytryptamine, 5-HT) has been concerned in the pathophysiology of various neuropsychiatric disorders. It is known to modulate emotion, cognition, endocrine activity, motor funtion, and pain. In the present study, the effects of treatment with thyroxine(T_(4)) on the postnatal development of serotonin-containing neuron with fetal alcohol effects in the rat raphe were investigated via immunohistochemistry. These experimental animals were divided into three groups : the alcohol-fed group received 35 calories liquid ethanol diet ; the control pair-fed group was fed a liquid diet in dextrin replaced alcohol isocalorically ; alcohol + T_(4) group received alcohol diet and exogenous thyroxine subcutaneously. After the pups were born, the pups of each were fostered by surragate mother. An average of four pups, one from each litter, were killed at days 0, 7, 14, 21, and 28 for each of the above three groups. Heavily-labelled serotonin-immunoreactive neurons increased in number from P7 in control pair-fed group. In contrast, serotonin-immunoreactive neurons appeared weakly in alcohol-exposed pups compared to control pair-fed and alcohol + T_(4)-exposed pups. The expression of serotonin immunoreactivity decreased according to increasing postnatal ages in alcohol-exposed pups. However, in alcohol + T_(4) group, the numbers and intensity of serotonin-immunoreactive neurons increased in contrast to the same ages of alcoholic group at all ages. Based on these results, it can be suggested that exogenous T_(4) treatment during developmental ethanol exposure may be related to the increase of serotonin synthesis during postnatal development of raphe nuclei.