Afferent connection of the trigeminal mesencephalic nucleus (Vmes) was examined.
Afferent connection from the lateral habenula (LHb) to the Vmes was found.
Vmes neurons received direct projection from the lateral division of LHb (LHbl).
Jaw movements may be directly modulated by LHbl-Vmes projection.
Jaw movements may be modulated by negative emotion signaled by LHbl neurons.