Abstract
Recent studies have demonstrated the existence of direct interactions between neurons and glial cells. To evaluate these interactions, we focused on interneuron/peri-interneuronal glial cell pairs in the hippocampal CA1 region, because of the close proximity of these two cells. Based on the electrophysiological, morphological and immunohistochemical studies, the peri-interneuronal glial cells were classified into astrocytes and oligodendrocytes, and we worked with the peri-interneuronal astrocytes (PNAC) in this study. Excitatory postsynaptic currents (EPSCs) recorded in an adjacent interneuron were suppressed by the depolarizing current injection into the PNAC. These suppression of EPSCs accompanied the increase of paired-pulse ratio and were blocked by the application of adenosine A1 receptor antagonist, indicating the involvement of presynaptic adenosine A1 receptors. Moreover, PNAC depolarization modified the directly induced firing of the interneuron. These results demonstrate directly modulatory effects of the PNAC on neuronal activities. [J Physiol Sci. 2006;56 Suppl:S44]
