David I. Wasserman, Joel M. J. Tan, Jun Chul Kim and John S. Yeomans To inhibit or excite RMTg GABA neurons, M4D or M3D DREADDs were utilized in GAD2::Cre mice. While no effect was observed with vehicle-induced locomotion (top panels), M4D inhibition of RMTg GABA neurons increased, and M3D excitation blocked, morphine-induced locomotion (bottom panels). M4 muscarinic receptors were found colocalized with 84% of μ-OR-positive RMTg GABA neurons. This suggests that muscarinic input to RMTg facilitates morphine-induced locomotion due to inhibition.
Link to Full Article: July 2016