[The relation between amygdaloid nucleus in rats and pain modulation].

Aim: To research the influence of noxious stimuli on the electric activities of pain-related neurons in several subnuclei of Amygdaloid Nucleus in rats.

Methods: Trains of the electric impulses applied to the sciatic nerve were used as noxious stimuli. The discharges of neurons were channeled off by glass microelectrode.

Results: Pain-related neurons existed in several subnuclei of Amygdaloid Nucleus. When the noxious stimuli were administered the frequency of discharges of pain-excited neurons (PEN) was increased while the frequency of pain-inhibited neurons (PIN) was decreased to the lowest level. The electric activities of PEN and PIN were matched with each other. Intraperitoneal injection of morphine (10 mg/kg) antagonized the effects of noxious stimuli on the pain-related neurons.

Conclusion: Several subnuclei of Amygdaloid Nucleus play an essential role in perceiving, integrating and transmitting the pain impulses. They are a part of the central nervous system in which pain information is controlled and managed.