Figure 3
Comparison of TH-IR axon innervation across five animals. Large TH-IR bundles entered the atria mainly through the SVC (bundles 1, 2), LPCV (bundle 3) or the entrance of the PVs to LA (bundle 4). The bundles entering the RA mainly sent their projections to innervate the right atrium, whereas bundles entering the LPCV mainly extended their projections towards the LA. A certain degree of overlap of innervation could be seen in the junction of LA and RA, SA, and AVN. Note: some fibers could have been cut or folded during the dissection which contributed to the few differences across animals. 1’ indicates the additional bundle found in some animals near bundle. Scale bar: 500 μm.
