Target-selective GABAergic control of entorhinal cortex output

The medial entorhinal cortex (MEC) is a major center for spatial navigation and memory. We demonstrate that cannabinoid type-1 receptor-expressing GABAergic basket cells selectively innervate principal cells in layer II of the rat MEC that project outside the hippocampus, but avoid neighboring cells giving rise to the perforant pathway to the dentate gyrus. These results show that the organization of GABAergic microcircuits reflects the long-distance axonal targets of principal neurons.