Figure 8.

Schematic summarizing the circuit organization of the claustrum. ClaC (green) neurons form rare synaptic connections with other ClaC neurons while PV (red) claustral neurons are highly interconnected with both chemical and electrical synapses. Connections from ClaC neurons to PV neurons and from PV neurons to ClaC neurons are also common. Although corticoclaustral axons form monosynaptic connections onto both ClaC neurons and PV neurons, the cortical input to PV neurons is stronger. Following optogenetic activation of corticoclaustral axons, ClaC neurons show both monosynaptic excitatory responses and disynaptic inhibitory responses.