Analgesia Induced by Trigeminal Nerve Stimulation (Electro-Acupuncture) Abolished by Nuclei Raphe Lesions in Rats *

Abstract

German

French

It was postulated by Kaada in 1974 [I] that acupuncture analgesia was produced by a humoral factor activating the descending midline ‘serotonin system’ from the raphe nuclei known to exert inhibitory effects on spinal pain transmission. The present crucial experiment, the elimination of acupuncture analgesia by selective lesions of these nuclei, has supported this assumption.

As nociceptive stimulation, electrical shocks were applied to the feet. Analgesia (reduced jump responses) was obtained by 2 sec⁻¹ trigeminal stimulation. The effect came on gradually during the 60 min stimulation period with return to the original value in about 1 hr, i.e. about the same time course as for morphine or acupuncture analgesia. Both effects are blocked by naloxone, indicating the involvement of the endogenous opiate system.

Selective electrolytic lesions of the nucleus raphe magnus (projecting to the spinal cord) as well as the nucleus raphe dorsalis or centralis superior (both projecting to the forebrain) eliminated the trigeminal-induced analgesia. Raphe magnus lesions reversed the response to foot shocks during trigeminal stimulation, suggesting the presence of a facilitatory pain system unveiled by removal of the raphe inhibition. Lesions of the nucleus raphe magnus or centralis superior both lowered the initial response level to foot shocks, possibly due to interruption of ascending fibers of the paleo-spinothalamic tract passing through this area.

Keywords

Acupuncture analgesia acupuncture mechanisms acupuncture experimental study naloxone serotonin nucleus raphe lesions morphine

Get full access to this article

View all access options for this article.

References

Kaada, B., Mechanisms of acupuncture analgesia, Tidsskr. norske Lægeforen. 94, 422–431, 1974.

Brodai

Taber

and Walberg

The raphe nuclei of the brainstem in thecal. II. Efferent connections, Journal of Comparative Neurology. 114, 239–259, I960.

Olivaras

J. L.

Redjemi

Guilbaud

and Besson

J. M.

Analgesia induced by electrical stimulation of the inferior centralis nucleus of the raphe in the cat, Pain 1, 139–145, I975.

Proudfit

K. and Anderson

E.G.

, Morphine analgesia: blockade by raphe magnus lesions, Brain Research 98, 612–618. 1975.

S. Mayer

D.J.

and Price

D.D.

, Central nervous system mechanisms of analgesia, Pain 2, 379–404, 1976.

Tenen

S. S.

Antagonism of the analgesic effect of morphine and other drugs by p-chloropheny (alanine, a serotonin depletor, Psychopharmacologia 12, 278–285, 1968.

Yakah

T. L.

DuChateau

C and Rudy

T.A.

, Antagonism by methysergide and cinanserin of the antinociceptive action of morphine administered into the periaqueductal gray, Brain 104, 367–372, 1976.

Mayer

D. J.

Price

D. D.

and Rafii

Antagonism of acupuncture analgesia in man by the narcotic antagonist naloxone, Brain 121, 368–372, 1977.

Lorens

S. A.

and Guldberg

H. C

Regional 5-hydroxytryptamine following selective midbrain raphe lesions in the rat, Brain Research 78, 45–56, 1974.

10.

Liebeskind

J. C

Mayer

D. J.

and Akil

Central mechanisms of pain inhibition. Studies of analgesia from focal brain stimulation, Advances in Neurology 4, 261–269, 1974.

11.

Samanin

Gheza

Mauron, C and Valzelli

, Effect of midbrain raphe lesionon the antinociceptive action of morphine and other analgesics in rats, Psychopharmacologia 33, 365–368, 1973.

12.

Chance

W. T.

Krynock

G. M.

and Rosecrans

J. A.

Effects of medial raphe magnus lesions on the analgesic activity of morphine and methadone, Psychopharmacology 56,133–137, 1978.

13.

Kaada

Neurophysiology and acupuncture: a review, Advances in Pain Research and Therapy 1,733–741, 1976.

14.

Andersson

Holmgren

and Roos

Analgesic effects of peripheral conditioning stimulation. II. Importance of certain stimulation parameters, Acupuncture & Eleciro-Therapeut. Res. Int. J. 2, 237–246, 1977.

15.

Srebro

and Lorens

S. A.

Behavior effects of selective midbrain raphe lesions in the rat, Brain Research 89, 303–325, 1975.

16.

Snyder

Opiate receptors and internal opiates, Scientific American 44-56,1977.

17.

Casey

K. L.

and Jones

E. G

. An overview of ascending pathways: brain stem and thalamus. Neurosciences Research Program Bulletin 16,103–118, 1978.

18.

Palkovits

and Jacobowitz

D. M.

Topographic atlas of catecholamine and acetylcholinesterase-containing neurons in the rat brain. II. Hindbrain (mesencephalon, rhombencephalon), Journal of Comparative Neurology 157, 29–42, 1974.

19.

Lundberg

Integration in the reflex pathway. In Nobel Symposium I. Muscular Afferents and Motor Control, pp. 275–305. Ed. by Granit

, Alqvist & Wiksell, Stockholm, and J. Wiley, New York, 1966.

20.

Andersson

S. A.

Ericson

Holmgren

and Lindqvist

Electro-acupuncture. Effect on pain threshold measured with electrical stimulation of teeth. Brain Research 63, 393–396, 1973.

21.

Omura

Patho-physiology of acupuncture treatment: effects of acupuncture on cardiovascular and nervous systems, Acupuncture & Eleciro-Therapeut. Res. Int. J. 1, 51–140, 1975.

22.

Omura

Electro-acupuncture: its electro-physiological basis and criteria for effectiveness and safety. I. Acupuncture & Eleciro-Therapeut. Res. Int. J., 1, 157–181, 1975.

23.

Omura

Editorial: acupuncture (with possible roles of serotonin and melatonin) and related unorthodox methods of diagnosis and treatment: non-invasive spheno-palatine ganglionic block, abrasion of nasopharyngeal mucosa and applied kinesiology, Acupuncture & Electro-Therapeut. Res. Int. J. 4, 69–89, 1979.

24.

Kaada, B., Unpublished observations, 1978.

25.

Greene

E. C

Anatomy of the Rat, The American Philosophical Society, Philadelphia, 1935.