GUT AND BRAIN EFFECTS OF AMERICAN GINSENG ROOT ON BRAIN-STEM NEURONALACTIVITIES IN RATS

Brainstem neurons receiving subdiaphragmatic vagal inputs were recorde d in an in vitro neonatal rat brainstem-gastric preparation. Aqueous e xtracts of American ginseng root (Panax quinquefolium L.) were applied to the gastric compartment or the brainstem compartment of the bath c hamber to evaluate the peripheral gut and central brain effects of the extracts on brainstem unitary activity. After Panax quinquefolium L. application to the gastric or brainstem compartment, a concentration-r elated inhibition in neuronal discharge frequency in the brainstem uni tary activity was observed, suggesting that Panax quinquefolium L. may play an important role in regulating the digestive process and modula ting brain function. In this study, pharmacological effects of America n-cultivated Panax quinquefolium L. and Chinese-cultivated Panax quinq uefolium L. were also compared. Our results suggest that American-cult ivated Panax quinquefolium L. possesses a significantly stronger gastr ic modulating effect on brain neuronal activity.