High resolution

Module 10: Figure CA3 hippocampal local circuits



Hippocampal CA3 local neuronal circuit.

The main components of the hippocampal CA3 local neuronal circuits are the CA3 pyramidal neurons and the inhibitory interneurons such as the basket cell and the oriens-lacunosum moleculare (O-LM) cell. The CA3 neurons provide an excitatory input to the inhibitory neurons, which, in turn, provide inhibitory inputs back to the CA3 neurons. The inhibitory interneurons interact with different regions of CA3: the axonal terminals of the basket cell (red triangles) innervate the soma whereas the long axons of O-LM innervate the distal dendrites. In addition, the components of these local circuits receive both excitatory and inhibitory inputs from other brain regions such as the medial septum-diagonal band of Broca (MS-DBB), the dentate gyrus and the entorhinal cortex. The structural organization of the CA3 pyramidal neurons and the basket cell and O-LM interneurons are shown in Module 10: Figure CA3 hippocampal neurons.