Interpreting the S1BF-ACC-LHb pathway in trigeminal neuralgia-associated affective behavior.

The study by Wang and colleagues proposes that three connected brain areas link facial nerve injury to pain and depression-like behavior in mice. The experiments are ambitious and potentially important. However, the nerve-injury model differs from the defining pattern of human trigeminal neuralgia, several behavioral and drug controls leave alternative explanations open, and measurements from many cells were not clearly separated from the animals that supplied them. Clarifying these issues, and distinguishing results from whole tissue from results specific to neurons, would make the causal and clinical implications more secure.