Evidence for cholinergic participation in frontal cortical potentials evoked by single impulse stimulation in the locus coeruleus area of freely moving rats
Heller, U.; Klingberg, F.
Biomedica Biochimica Acta 48(4): 261-267
1989
ISSN/ISBN: 0232-766X PMID: 2546538 Document Number: 327967
Single impulse stimulation in the area of locus coeruleus (LC) in freely moving rats evoked bilateral symmetrical potentials (EP) in the frontal cortex. Threshold intensity for this potential was higher when the stimulus electrode was in the LC than in the cholinergic dorsal parabrachial nucleus lateral of LC. Amplitudes and peak times of this EP were constant during relaxed wakefulness, exploratory behavior and unaffected by .beta.-blockade (propranolol, 2.5 mg/kg i.p.). Their amplitudes were strongly decreased and the peak times of later negativity (N50) were prolonged during slow wave sleep and by muscarinic blockade with scopolamine (0.5 mg/kg i.p.) which induced active behavior and synchronized EEG. These data suggest a direct participation of cholinergic structures in cortical potential evoked by electrical LC stimulation. Relations between stimulus effect and behavior regulating systems are discussed.