Stimulation of the dorsal noradrenergic dundle and field potentials in the locus coeruleus.

Field potentials were recorded from the locus coeruleus following electrical stimulation of the rat midbrain. Activation of a discrete area situated ventrolateral to the central gray evoked long-latency potentials in the locus coeruleus while stimulation of other midbrain sites did not. Damage to this discrete area resulted in a depletion of norepinephrine in the cerebral cortex suggesting that it is a segment of the dorsal noradrenergic bundle arising from the locus coeruleus.