PHARMACOLOGICAL PROPERTIES OF BENZAZOLES. III. EFFECT OF 2-AMINOBENZOTHIAZOLES ON THE ELECTROENCEPHALOGRAM

¹ Department of Pharmacology, University of Illinois College of Medicine, Chicago 12, Illinois

The effects of a series of 2-aminobenzothiazoles on the EEG of normal and mesencephalic transected cats have been studied and compared to those of mephenesin.

1. 2-Aminobenzothiazole more markedly increased the synchronization of cortical discharges than did mephenesin at 50 mgm./kgm. Twice this dose produced bursts of fast-activity in the EEG. Spindles caused by mesencephalic section were abolished.

2. Compounds with substitutions in position 6 lowered the amplitude without changing the frequency of the waves in the EEG of normal animals. These drugs also abolished the spindles in the EEG of decerebrate cats.

3 The effects on the EEG of the compounds with substitutions in position 4 showed depression with low doses as evidenced by slow waves in the EEG. Stimulation at higher doses was shown by fast activity or seizure patterns. These drugs altered the spindles in the EEG of cerveau isolé preparations to normal-appearing activity as though the sleeping animals had been aroused by the drug.

4. The drugs differed in their action according to the position on the parent compound at which the substitution was made rather than by the radical which was substituted. Substitution at position 4 rendered the compound stimulatory.

Substitution at position 6, on the other hand, failed to give stimulation and enhanced the depressant effects of the parent compound on the cortex and cortico-thalamic circuits.