Portal de Periódicos da CAPES

Serotonergic regulation of noradrenergic coerulean neurons: electrophysiological evidence for the involvement of 5-HT2 receptors

1988; Elsevier BV; Volume: 154; Issue: 3 Linguagem: Inglês

10.1016/0014-2999(88)90203-8

1879-0712

Eugen Gorea, Joëlle Adrien,

Neuroscience and Neuropharmacology Research

To determine the type of serotonergic receptor involved in the modulation of noradrenergic neuronal activity in the locus coeruleus, the effects of 4 systemically administered serotonergic drugs were tested on the firing rate of noradrenergic neurons in the locus coeruleus of rats under chloral hydrate anaesthesia. The serotonergic agonist, quipazine (1 mg/kg), and the selective 5-HT2 agonist, DOB (50-100 micrograms/kg), induced a pronounced decrease of the discharge frequency. This effect could be prevented or reversed by the selective 5-HT2 antagonist, ketanserin (4-8 mg/kg). Ketanserin alone and the 5-HT1 agonist, RU 24969, had no or a weak excitatory action on the neuronal activity of the locus coeruleus. We conclude that the serotonergic control of noradrenergic neurons in the locus coeruleus is mediated by post-synaptic 5-HT2 receptors because the quipazine-ketanserin effects on this unit activity persisted after depletion of serotonergic presynaptic stores.