(A) Left: illustration of viral setup for the structural circuit mapping method. AAV5-hSyn-ChR2-EYFP was injected into the input cortical nucleus for anterograde terminal labeling and AAVrg-CAG-tdTomato was injected in output cortical nuclei for retrograde soma labeling in claustrum. Right: representative image of fluorescently labeled spiny claustrum projection neurons for fluorescence-guided slice recordings.
(B) Cartoon of all 35 frontal cortical-claustro-cortical circuits tested with 5 input frontal cortical regions and 7 output regions.
(C) Top: diagram of ex vivo ACC trans-claustral circuits tested (projecting through claustrum to ACC, plPFC, ilPFC, OFC, RSC, PtA, and V1/V2 cortices; n = 15 type I cells; n = 15 type II cells each circuit) and corresponding representative voltage traces for recorded type I and II claustrum neurons. Bottom: heatmaps depicting average change in membrane potential across each recording following each light pulse stimulation (blue marker) for type I and II claustrum neurons. Only recordings from maximum light intensity (3 mW) are shown.
(D) Diagram of ex vivo plPFC trans-claustral circuits tested (projecting to plPFC, ACC, ilPFC, OFC, RSC, PtA, and V1/V2 cortices, respectively; n = 15 type I cells; n = 15 type II cells each circuit) and corresponding representative voltage traces for recorded type I and II claustrum neurons.
(E) Diagram of ex vivo ilPFC trans-claustral circuits tested (projecting to ilPFC, ACC, plPFC, OFC, RSC, PtA, and V1/V2 cortices; n = 15 type I cells; n = 15 type II cells each circuit) and corresponding representative voltage traces for recorded type I and II claustrum neurons.
(F) Diagram of ex vivo OFC trans-claustral circuits tested (projecting to OFC, ACC, plPFC, ilPFC, RSC, PtA, and V1/V2 cortices; n = 15 type I cells; n = 15 type II cells each circuit) and corresponding representative voltage traces for recorded type I and II claustrum neurons.
(G) Diagram of ex vivo aINS trans-claustral circuits tested (projecting to ACC, plPFC, ilPFC, OFC, RSC, PtA, and V1/V2 cortices, respectively; n = 15 type I cells; n = 15 type II cells each circuit) and corresponding representative voltage traces for recorded type I and II claustrum neurons. n = 1,050 cells total.
Horizontal scale bars: (A) top: 500 μm, bottom: 200 μm and (C–G) 100 ms. Vertical scale bars: (C–G) 40 mV. Portions of this figure were created with BioRender.com.