Electromyographic effects of serotonin application into the lateral vestibular nucleus.
Electromyographic responses (EMGs) of limb muscles were studied during microiontophoretic application of 5-hydroxytryptamine (5-HT) into the lateral vestibular nucleus (LVN) or the spinal vestibular nucleus (SpVe) of anaesthetized rats. The aim was to ascertain whether the level of 5-HT in these nuclei was able to modulate muscle responsiveness. Increased levels of 5-HT in LVN (and to a weaker extent in SpVe) enhanced the EMGs of proximal extensor muscles and depressed those of flexors. The 5-HT2A receptor antagonist ketanserin, applied into the LVN, prevented 5-HT effects on EMG-evoked responses. It is concluded that 5-HT can modulate the motor output via the vestibulospinal pathway, exerting a differential control over flexor and extensor muscles.
Dipartimento di Scienze Fisiologiche, Università di Catania, Italy.
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G
Li Volsi
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Licata
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L
Ciranna
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C
Caserta
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F
Santangelo
D000818:Animals; D004576:Electromyography / Q000187:drug effects*; D005552:Forelimb / Q000502:physiology; D007478:Iontophoresis; D007650:Ketanserin / Q000494:pharmacology; D009068:Movement / Q000187:drug effects / Q000502:physiology; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D014726:Vestibular Nuclei / Q000187:drug effects / Q000502:physiology*
D012702:Serotonin Antagonists; D012701:Serotonin; D007650:Ketanserin