Objective To observe whether endomorphin-2-immunoreactive (EM2-ir) neurons in the trigeminal ganglion(TG) project to the medullary dorsal horn(MDH) in the rat.

• 目的 观察大鼠三叉神经节(TG)内的内吗啡肽2(EM2)阳性神经元向延髓背角(MDH)的投射情况。