BRAIN FINDING GETS SCIENTISTS DOPE ON DOPE

   LONDON - Cannabis, marijuana, hash, grass, pot, ganja, bhang - one
way or another people have been smoking or eating the Indian hemp plant
for thousands of years.
   It's only now that scientists are beginning to understand how the
drug works.
   Their answers could help in the search for novel therapies for a
range of ailments from glaucoma to mental disorders, and shed new light
on the complex chemical working of the brain.
   Since the late 1980s scientists have known that the brain contains
tiny "receptors" through which the main active ingredient in cannabis,
tetrahydrocannabinol (THC), acts.
   Until last year they were mystified as to why humans had chemical
"docking sites" which let them get "high."
   Then, in December a new chemical was found in pigs' brains which
seemed to do naturally what cannabis does when smoked.  It was named
anandamide, from the Sanskrit "ananda" for "bliss."
   Now, Israeli scientists have confirmed that finding.
   Using cells grown in culture they proved, in a paper published last
month, that anandamide binds to the same receptors as THC and triggers
similar responses.
   "It provides further evidence for the idea that we have a system in
the brain which is made up of cannabis receptors," said Aberdeen
University's Dr. Roger Pertwee, secretary of the International Cannabis
Research Society and one of the original discoverers of anandamide.
   "It's very exciting because this is a newly discovered system of the
brain about which we know nothing."
   While ananadamide has yet to be isolated in human brains, he believes
it's only a matter of time before it is tracked down.
   What the substance is doing in our brains remains a mystery.