Neurosci Lett. 1990 Oct; 118(2): 205-7.

Effect of low-frequency electric stimulation on in vivo release of cholecystokinin-like immunoreactivity in medial thalamus of conscious rat.

Xu M, Aiuchi T, Nakaya K, Arakawa H, Maeda M, Tsuji A, Kato T, Takeshige C, Nakamura Y.

Department of Life Chemistry, Tokyo Institute of Technology, Japan.

Release of cholecystokinin-like immunoreactivity (CCK-LI) in the medial thalamus of conscious rats was measured by brain dialysis and enzyme immunoassay. Analgesia caused by low-frequency electric stimulation of the tibial muscle, the tsusanli acupuncture point, was judged by change of pain threshold due to the stimulation. Medical thalamic CCK-LI released was increased by peripheral electric stimulations of both the acupuncture point and the non-acupuncture point. Results suggest that CCK acts as a neurotransmitter in the medial thalamus, a part of the analgesia inhibitory system.