Pro-thyrotropin-releasing hormone concentrations in the brain of ataxic mice

Concentrations of pro-thyrotropin-releasing hormone (pro-TRH) were studied in the brain of the Weaver ataxic mouse, the Purkinje cell degenerative mouse (pcd-ataxic mouse), the Staggerer ataxic mouse and the C3H mouse. The brain tissue was dissected into 7 parts, e.g., hypothalamus, cerebrum, thalamus, striatum, brain stem, cerebellum and cervical spinal cord. Pro-TRH concentrations in each part of the brain were measured by radioimmunoassay. Pro-TRH concentrations in the brain of Weaver ataxic mice, pcd-ataxic mice and Staggerer ataxic mice were significantly higher in the thalamus, brain stem, cerebellum and cervical spinal cord. Pro-TRH concentrations in the hypothalamus, striatum and cerebrum of ataxic mice did not differ from those of controls. The elution profile of acetic acid extracted cerebellum of ataxic mice on Sephadex G-50 was identical to that of synthetic pro-TRH. These findings suggest that changes in pro-TRH concentrations in the brain may play a pathophysiological role in ataxic mice.