Protocol for detecting plastic changes in defined neuronal populations in neuropathic mice

Characterization of synaptic plasticity changes via optogenetic manipulation between defined neuronal populations is important for mapping neural circuits involved in normal brain functions and disorders such as neuropathic pain. However, determining the strength of synaptic transmission based on optogenetic manipulation is challenging due to variability in opsin expression. This protocol describes the use of slice electrophysiology combined with optogenetics to examine synaptic transmission in genetically defined neuronal populations from neuropathic mice. We detail surgical procedures of spared nerve injury for inducing neuropathy. For complete details on the use and execution of this protocol, please refer to Huang et al. (2019) and Huang et al. (2021).