A critical test of the hippocampal theta model of anxiolytic drug action

► Hippocampal theta rhythms are associated with anxiety and suppressed by known anxiolytic drugs. ► Theta suppression has been used as a neurophysiological model for anxiolysis. ► Prior validation of this model has used known anxiolytics, thus, a critical test would use a non- or unknown anxiolytic. ► INaP currents are necessary for the expression of hippocampal theta, and are suppressed by the anticonvulsant phenytoin. ► Phenytoin suppressed both theta and anxious behaviour in the plus-maze, providing prima facie validation for the model.