Generation of a NK1R-CreER knockin mouse strain to study cells involved in Neurokinin 1 Receptor signaling.

The Neurokinin 1 Receptor (NK1R), which binds Substance P, is expressed in discrete populations of neurons throughout the nervous system, where it has numerous roles including the modulation of pain and affective behaviors. Here, we report the generation of a NK1R-CreER knockin allele, in which CreERT2 replaces the coding sequence of the TACR1 gene (encoding NK1R) in order to gain genetic access to these cells. We find that the NK1R-CreER allele mediates recombination in many regions of the nervous system that are important in pain and anxiety including the amygdala, hypothalamus, frontal cortex, raphe nucleus, and dorsal horn of the spinal cord. Other cell types that are labeled by this allele include amacrine cells in the retina and fibroblasts in the skin. Thus, the NK1R-CreER mouse line is a valuable new tool for conditional gene manipulation enabling the visualization and manipulation of cells that express NK1R.