Differential effects of 5-HT1 and 5-HT2 receptor agonists on hindlimb movements in paraplegic mice.
Prog Neuropsychopharmacol Biol Psychiatry
; 28(6): 1053-60, 2004 Sep.
Article
em En
| MEDLINE
| ID: mdl-15380867
ABSTRACT
The effects induced by serotonergic (5-HT) agonists of the 5-HT1 and 5-HT2 subclasses were examined on hindlimb movement generation in adult mice completely spinal cord transected at the low thoracic level. One week postspinalization, intraperitoneal injection (0.5-10 mg/kg) of meta-chlorophenylpiperazine (m-CPP; 5-HT(2B/2C) agonist) or trifluoromethylpiperazine (TFMPP; 5-HT(1B) agonist) failed to induce locomotor-like movements. However, dose-dependent nonlocomotor movements were induced in air-stepping condition or on a motor-driven treadmill. In contrast, hindlimb locomotor-like movements were found after the injection of quipazine (5-HT(2A/2C) agonist; 1-2 mg/kg). Combined with L-DOPA (50 mg/kg, i.p.), low doses of quipazine but not of m-CPP and TFMPP produced locomotor-like and nonlocomotor movements in air-stepping condition or on the treadmill. Subsequent administration of m-CPP or TFMPP significantly reduced and often completely abolished the hindlimb movements induced by quipazine and L-DOPA. Altogether, these results demonstrate that 5-HT(2A/2C) receptor agonists promote locomotion while 5-HT(1B) and 5-HT(2B/2C) receptor agonists interfere with locomotor genesis in the hindlimbs of complete paraplegic mice. These results suggest that only subsets of spinal 5-HT receptors are specific to locomotor rhythmogenesis and should be activated to successfully induce stepping movements after spinal cord injury.
Buscar no Google
Base de dados:
MEDLINE
Assunto principal:
Paraplegia
/
Agonistas do Receptor de Serotonina
/
Agonistas do Receptor 5-HT1 de Serotonina
/
Agonistas do Receptor 5-HT2 de Serotonina
/
Membro Posterior
Limite:
Animals
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article