Studies are underway to ascertain information on (A) the effects of delta 8 and delta 9 tetrahydrocannabinol (delta 8 and delta 9 THC) on experimental seizure models; (B) the influence of THC on cortical and subcortical electroencephalograms (EEG) and corresponding overt behavior; and (C) the specificity of antagonistic drugs to the central effects of various hallucinogens. The effects of THC on electrically induced seizures (maximal and minimal seizure tests), drug induced seizures (e.g., pentylenetetrazol, picrotoxin, strychnine) and upon audiogenic seizure phenomenon will be assessed in mice and rats in order to determine anticonvulsant profiles of the marihuana constituents. It is anticipated that these studies will provide basic pharmacological knowledge in experimental animals concerning the potential therapeutic usefulness of THC in recurrent seizure states. Utilizing quantitative EEG and behavioral monitoring techniques, loci and mechanisms of action of THC are being investigated especially with regard to central and adrenergic and cholinergic systems. Moreover, these parameters coupled with autonomic measures will be used to assess the specificity of drug antagonists (e.g., phenothiazines, butyrophenones, benzodiazepines) to acute effects of some hallucinogens (i.e., THC, mescaline, psilocybin and lysergic acid diethylamide or LSD). Such studies should yield valuable information as to possible central mechanisms of hallucinogens as well as develop a pharmacological rationale for treating their adverse acute effects.