ACUPUNCTURE

Study seeks to show how acupuncture really works

Sci­en­tists are pre­sent­ing a new the­o­ry on the mech­an­ism of acupunc­ture—a tra­di­tion­al Chin­ese heal­ing tech­nique that seems to work for some ail­ments, though West­ern re­search­ers don’t un­der­stand why.

East­ern prac­ti­tion­ers say ac­u­punc­ture works by chang­ing en­er­gy flows in the body. West­ern sci­en­tists tend not to buy this ac­count, ar­gu­ing that the pro­posed en­er­gy fields have nev­er been seen or meas­ured.

An ac­u­punc­ture nee­dle com­mon­ly used to­day. (Cred­it: Takumi Fu­jita )

Ac­u­punc­ture in­volves in­sert­ing thin nee­dles in­to the skin at se­lected points to treat a range of cond­itions. Sev­er­al stud­ies have shown that it works for cer­tain kinds of pain; a study last year found that ac­u­punc­ture beats con­ven­tion­al treat­ment for chron­ic low­er back pain.

The new stu­dy, pub­lished in the May 30 on­line is­sue of the jour­nal Na­ture Neu­ro­sci­ence, sug­gests that ac­u­punc­ture works by ac­ti­vat­ing pain-sup­press­ing re­cep­tors, or mol­e­cules, in the ar­ea of the body where the nee­dle is in­sert­ed.

In the re­search, Mai­ken Ned­er­gaard of the Uni­vers­ity of Roch­es­ter Med­i­cal Cen­ter in New York and col­leagues in­sert­ed fi­ne nee­dles in­to the mouse equiv­a­lent of a tra­di­tion­al ac­u­punc­ture point near the knee. The re­search­ers ro­tated these nee­dles in­ter­mit­tently as is prac­ticed by acupunc­tur­ists.

This eased the pain re­ac­tions of mice with an in­flamed paw, the re­search­ers found. It al­so strongly boosted the lo­cal tis­sue con­centra­t­ion of a neu­ro­trans­mitter, or a mol­e­cule that trans­mits sig­nals through nerves, called aden­o­sine.

Pain re­lief re­quired the pres­ence of a par­tic­u­lar re­cep­tor for aden­o­sine, the re­search team found. A re­cep­tor is a mo­lec­u­lar struc­ture on the sur­face of a cell that acts as a sort of gate­way for al­low­ing spe­cif­ic types of “mes­sen­ger” mol­e­cules to de­liv­er a sig­nal.

The re­cep­tor in ques­tion, called the aden­o­sine A1 re­cep­tor, is known to lie on pain-transmitting nerve fibers and to re­duce the ac­ti­vity of these fibers when ac­tivated, ac­cord­ing to Ned­er­gaard and col­leagues.

The team found that no pain re­lief or aden­o­sine eleva­t­ion was ob­served when the nee­dles were in­sert­ed in­to the ac­u­punc­ture point with­out rota­t­ion. They al­so not­ed that a drug that pro­longs the life­time of aden­o­sine in live tis­sue helped to pro­long the pain-eas­ing ef­fect of mouse ac­u­punc­ture.

“Thus, med­ica­t­ions that in­ter­fere with A1 re­cep­tors or aden­o­sine me­tab­o­lism may im­prove the clin­i­cal ben­e­fit of ac­u­punc­ture,” the re­search­ers wrote.