Electrophysiological perspectives on locus coeruleus: Its role in cognitive versus vegetative functions

The hypothesis that the locus coeruleus (LC) may be involved in the control of cognitive and/or vegetative processes is reviewed, primarily focusing on electrophysiological experiments. With the impact of this nucleus on target neurons in different brain areas and with the activity pattern of LC neurons in conscious animals, the electrophysiological data are, to a large extent, in keeping with the postulated role of the LC in cognitive processes. A considerable body of evidence from lesion and stimulation experiments points to a possible function of the LC in the control of autonomic processes. In particular, many studies suggest a role in the central control of blood pressure. The electrophysiological data, although not entirely ruling out such a function, are not in keeping with this hypothesis. In conclusion, although there is a case for the LC’s having a role both in the cognitive sphere and in the vegetative sphere, the exact role of the LC in both of them remains to be elucidated.