抄録
We aimed to clarify the overall distribution of glycinergic neurons in the brainstem and cerebellum in rats, using in situ hybridization for mRNA encoding glycine transporter 2 (GLYT2). We combined this method with in situ hybridization for mRNA encoding glutamic acid decarboxylase isoform 67 (GAD67), and have presented global and detailed views of the distribution of glycinergic neurons in relation to GABAergic neurons. In addition to this single-detection study, we performed double-detection of GLYT2 mRNA and GAD67 mRNA to determine the distribution of neurons co-expressing these mRNAs. A number of previous studies have shown immunohistochemically that many areas involve neurons in which glycine and GABA (or GAD) colocalize, and the present study has confirmed that such areas certainly involve double-labeled neurons with GLYT2 and GAD67 mRNAs. In addition, the present results have shown that many other areas of the brainstem and cerebellum involve double-labeled neurons. In particular, when lightly labeled GLYT2 mRNA-positive neurons were distributed within the area of GAD67 mRNA-positive neurons, almost all such GLYT2 mRNA-positive neurons were also GAD67 mRNA-positive. Areas or neuron groups expressing exclusively GLYT2 mRNA or GAD67 mRNA were rather limited, such as the superior and inferior colliculi, nucleus of the trapezoid body, raphe pallidus, area postrema, and Purkinje cells. The present study suggests that the colocalization of GLYT2 and GAD67 mRNAs, which may represent the corelease of glycine and GABA from single neurons, is more widespread than has been reported. [Jpn J Physiol 54 Suppl:S183 (2004)]
