Fig. 6.

The LC innervation of the spinal cord originates from ps:LC module rather than pfc:LC. (A) Paired injections of CAV2-PRS-mCherry-ChR2 and CAV2-PRS- EGFP-2A-PSAM to the lumbar spinal dorsal horn and prefrontal cortex (CG1), respectively, labeled distinct subsets of LC neurons shown in parasagittal section – note larger numbers of somata labeled from pfc. (B) Examination of spinal cord sections (L2 dorsal horn shown) demonstrated the presence of numerous mCherry-ir axons (B₂) originating from transduced ps:LC neurons with a complete absence of EGFP-ir fibres (B₃) indicating that the pfc:LC neurons do not contribute to the spinal innervation. Note the increased density of axons seen in the superficial dorsal horn. Red arrows indicate mCherry-filled axons.