UCLA

Reelin signaling has a prominent role in correct neuronal positioning within the spinal cord dorsal horn. Reelin (Reln), its two lipoprotein receptors, and Disabled-1 (Dab1) are highly expressed within laminae I-II on neurons that receive itch stimulation and dab1-/- mice display reduced responses to itch-evoking stimuli compared to controls. Gastrin-releasing peptide (GRP) and Neurokinin-1 receptor (NK1R) expressing neurons reportedly function in itch signaling. To understand how mutations in Reln or dab1 affect itch responses, we examined GRP- and NK1R-expressing neurons in dab1+/+;GrpeGfp and dab1-/--GrpeGFP mice. We identified a few large Reelin-NK1R- and GRP-NK1R-expressing neurons within lamina I, with morphological characteristics of projection neurons in dab1-/-;Grp mice. We also observed Reelin-NK1R-expressing neurons in dab1-/-;Grp mice which were mispositioned between laminae II-III. These findings, in combination with our previous reports of Dab1-NK1R-expressing neurons, suggest that the Reelin-signaling pathway influences many NK1R-expressing neurons in the superficial dorsal horn.