A - B. IHC illustrating examples of a KOR-cre-labeled (red) lanceolate fiber (A) or circumferential fiber (B) innervating hair follicles in the hindpaw skin and co-localization with NF200 (green). KOR-cre afferents were labeled with a Cre-dependent virus (AAV.FLEX.ChR2-tdTomato; IT in adult). Data are representative of n = 2 mice. Scale bar = 10 μm.
C - D. Single fiber recordings were performed in KOR-cre, ROSAlslChR2-eYFP mice and fibers were identified with optogenetic tagging by their response to blue light stimulation of their cutaneous receptive field. A representative trace of a single fiber recording from a KOR-cre-positive rapidly adapting A-fiber (C) and large dynamic range fiber (D) upon application of a mechanical stimulus the receptive field in the skin (5 sec, 10 mN) Data are representative of n = 4 cells of each type.