Distribution of thyrotropin-releasing hormone (TRH) receptors in the brain of the ataxic mutant mouse, rolling mouse Nagoya.

Thyrotropin-releasing hormone (TRH) and its analog, TA-0910, ameliorate the ataxia of the mutant mouse, rolling mouse Nagoya, by metabolic normalization in the ventral tegmental field (VTF). We here investigated the distribution of cerebral TRH receptors in the rolling mouse to clarify the sites of action of these drugs. TRH receptors were widely distributed in multiple brain areas, including in the VTF and the cuneiform nucleus (CnF) which terminates in the VTF. These results suggest that TRH and TA-0910 directly activate the VTF by acting on TRH receptors in the VTF and indirectly activate it through the receptors in the CnF.