Effect of des-tyrosine-gamma-endorphin on neocortical spike-and-wave spindling in DBA/2J mice.

The effect of a beta-endorphin cleavage product devoid of opioid effects, des-tyrosine-gamma-endorphin (DT gamma E) on the neocortical spike-and-wave spindling episodes in the electrocorticogram (ECoG) of DBA/2J mice was studied. DT gamma E (0.01-1.0 mg/kg, i.p.) dose dependently reduced the spike-and-wave bursts duration. However, the low dose did not induce consistent modifications of the spike-and-wave bursts number while the dose of 0.1 and 1.0 mg/kg induced a progressive diminution. Furthermore, at all doses DT gamma E did not induce any alterations of the spike-and-wave bursts amplitude, frequency, and desynchronized activity when compared to the pre-drug period. These results indicate that this beta-endorphin fragment may affect brain excitability.