NADPH-diaphorase activity in the frontal cortex of NBM-lesioned rats treated with verapamil

The effect of the calcium antagonist verapamil on NADPH-diaphorase activity was studied in the frontal cortex of rats with lesioned nucleus basalis ma gnocellularis (NBM). Treatment with verapamil (5 mg/kd/12h ip) started 24 h after NBM lesions and lasted 8 days. Animals were sacrificed on day 21 aft er NBM-lesions. There were no significant differences between control, sali ne- and verapamil-treated NBM-lesioned rats in the total number of neurons expressing NADPH-diaphorase. However, the number of neurons which show loss of enzymatic reaction in their processes was significantly higher in salin e-treated NBM-lesioned rats. This may relate to incipient neurodegeneration in these neurons. The obtained reactive decrease of NADPN-diaphorase stain ing was abolished by verapamil treatment, which suggests a significant neur oprotective effect of this calcium antagonist.