the discriminative-stimulus effects of the adenosine analogs neca , cpa , 2-chloroadenosine and the r- and s-isomers of n6-phenylisopropyladenosine ( pia ) , of the adenosine antagonists caffeine and 8-cyclopentyltheophylline ( cpt ) , and of selected drugs from other classes ( haloperidol , pentobarbital , diazepam and morphine ) were determined by administering cumulative doses i.v . before sequential components of the experimental session .
C0000275
2-chloroadenosine
C0001443
adenosine