Activation-induced changes in evoked and slow brain potentials: effects of cocaine in awake rabbit

To study the interrelations between event-related potentials and brain activation, evoked responses to visual stimulation registered from occipital cortex and hippocampal CA1 region were investigated in awake animals administered cocaine (2 mg/kg, SC) or saline. Administration of COCA resulted in longterm significant changes in heart and breathing rates and spontaneous EEG (desynchronization in the occipital cortex and slow rhythmic theta activity in the hippocampus), inhibition of animal responses to noxious electroshock stimuli and modification in different amplitudes of evoked responses (mainly in the cortex, the enhancement of negativity and bidirectional changes in late slow phase). Principally identical but more or less changes were observed in response to administration of saline. Obtained results are discussed in respect to their interrelations with the general activation organism's response and the modification of brain metabolism induced by cocaine in restrained rabbits.