Connective tissue surrounding the DRG

Hi all,

I am trying to find information about the connective tissue surrounding the DRG and its role in pain. However, I am having a hard time finding information about this portion of the DRG’s anatomy and I think its due to inconsistency in terminology. I’ve seen it called “connective tissue”, “capsule”, “sheath”, “plexus”, “epineurium/perineurium” and various combinations of each. I’m trying to figure out what cell types are located there (is it similar to other connective tissue throughout the body? blood vessels mainly?), what types of fibers innervate this region (most diagrams simply say “nerve.” Are these sympathetic fibers? What’s there?)

If anyone can help me out, it would be very much appreciated!



Hi Stephanie:

We have recently run a single-cell analysis of the DRG tissue and found mostly neurons, but also satellite glial cells, macrophages, endothelial cells and Schwann cells. Although we did not detect them with our analysis, it is well-known that few T cells are also present in DRG in physiological conditions.

Surrounding the DRG tissue are mostly blood vessels and sympathetic fibers.

Sounds like someone needs to more carefully characterize the sheath! My guess would be fibroblasts and connective tissue make the sheath.

Hi @sshiers, I just saw your query. I’m not sure you are talking about the same thing I’m thinking about but we are also interested in this adjacent tissue of DRGs. In fact, there is evidence of leptomeninges recovering central part of DRGs. There is also evidence that immune cells (T-cells) are infiltrating these leptomeninges after peripheral nerve injury. We are trying to characterize better this cells. I hope it helps.

(Du B, Ding YQ, Xiao X, Ren HY, Su BY, Qi JG. CD4+ αβ T cell infiltration into the leptomeninges of lumbar dorsal roots contributes to the transition from acute to chronic mechanical allodynia after adult rat tibial nerve injuries. J Neuroinflammation. 2018 Mar 15;15(1):81. doi: 10.1186/s12974-018-1115-7).