Distribution of Calretinin-immunoreactive Unipolar Brush Cells in Ataxic Mutant Pogo Mice Cerebellum / 대한해부학회지

Unipolar brush cells (UBCs) are a class of putative interneurons found in the granular layer of mammalian cerebellum and dorsal cochlear nucleus. The unipolar brush cells (UBCs), as with granular cells, which receives afferent synaptic input from extrinsic mossy fiber and whose axons branch in the granular layer and establish a system of cortex-intrinsic mossy fibers, which synapse with granule cells and other UBCs. In general, UBCs have been identified most readily by their expression of the calcium-binding protein, calretinin. The purpose of this study was to provide information about UBCs distributions of the new ataxic animal model, pogo mouse cerebellum using anti-calretinin immunohistochemistry, immunofluorescence and its effect on calcium homeostasis. Through the examination of calretinin immunohistochemistry and immunofluorescence, we observed that many calretinin immunoreactive UBCs were distributed widely throughout the lobules IX and X of the granular layer of both group. But, we found the number of calretinin immunoreactive UBCs of ataxic pogo (pogo/pogo) mouse was decreased and distribution pattern was altered, compared to control mouse. This result also suggest that reduced calretinin expression may effect on cerebellar Ca2+/-homeostasis, and it may in turn, explain the impaired motor coordination found in the ataxic pogo mice.

Elevated Serotonin-immunoreactive Neurons in the Raphe Nucleus of the Ataxic Mutant Mouse, Pogo / 대한해부학회지

This study was carried out to investigate the distribution of serotonin-immunoreactive neruons in the raphe nucleus of the ataxic pogo (pogo/pogo) mice derived from a Korean wild mice. Using by immunohistochemistry, we undertook to elucidate any correlation between the serotonin expression and behavior ataxia including abnormal hindlimb extension in the ataxic pogo mice. The present study has two important findings. First, serotonin immunoreactivity was increased in the raphe nucleus of the ataxic pogo mice. Second, serotonin immunoreactivity was different with the region of raphe nucleus. In the dorsal part of dorsal raphe nucleus (DRD), ventrolateral part of dorsal raphe nucleus (DRVL) and median raphe nucleus (MR), serotonin immunoreactivity was increased, whereas the ventral part of dorsal raphe nucleus (DRV) and interfascicular part of dorsal raphe nucleus (DRI) was similar with the control mice. Therefore, elevated expression of the serotonin in the raphe nucleus of ataxic pogo mice might be a source of behavior ataxia and may be related with the induction of the ataxic phenotype including abnormal hindlimb movements.