Direct projections from CA1 to the superior temporal sulcus in the monkey, revealed by single axon analysis

Anterograde tracer injections in the middle sector of CA1 in macaque monkeys demonstrate a direct projection to the fundus of the anterior superior temporal sulcus, in area IPa. Terminations are predominantly in layer 3. With regard to both terminal and arbor configuration, these hippocampal-cortical connections are morphologically similar to corticocortical connections to temporal association cortex. This report provides additional evidence of direct CA1 connections to particular multimodal cortical areas.