RETICULAR MULTIPLE UNIT ACTIVITY DURING A PROGRESSION OF STATES INDUCED BY CNS EXCITANTS .3.

The EEG, gross behavior and multiple unit activity were recorded during the continuous progression of states induced by amphetamine (d-, and meth-), lysergic acid diethylamide (LSD-25), mescaline, gamma-hydroxybutyrate, pentylenetetrazol or phencyclidine. The drugs appear to fall within a pattern of progressively increasing excitatory states. The least active agents induce only the initial phase, i.e., excited: amphetamine; then hallucinoid: LSD-25 and mescaline. The more potent agents transcend these initial phases and induced generalized seizures: gamma-hydroxybutyrate, phencyclidine and pentylenetetrazol. The reticular multiple unit activity increased slightly during the initial two phases; then following gamma-hydroxybutyrate the basal level fell progressively while the fluctuation rose markedly, whereas following pentylenetetrazol the multiple unit activity progressively increased. During the generalized seizures the unit activity was markedly elevated in both of these groups; then the unit activity fell during the brief period of post-ictal depression followed by a return of each drug group to the unit activity levels noted during the pre-seizure state. © 1969.