RESUMO
In anaesthetised and paralysed rats with chronic constriction of the sciatic nerve, the effects of subcutaneous contralateral lidocaine (100 microl) on the activity of lumbar (L(4)-L(5)) wide dynamic range neurons ipsilateral to the constriction have been investigated. The results show reduction of the spontaneous hyperactivity for 60 min; suppression or reduction of the responses to contralateral noxious stimulation for 60 min; lack of effect on the responses to ipsilateral noxious stimulation, except for the afterdischarge duration, reduced for 60 min. The finding that the altered neuronal activity following peripheral nerve injury associated to behavioural signs of neuropathic pain, can be reduced by contralateral treatment, may provide further suggestions to neuropathic pain mechanisms and management.
Assuntos
Potenciais de Ação/efeitos dos fármacos , Anestésicos Locais/farmacologia , Lateralidade Funcional/efeitos dos fármacos , Lidocaína/farmacologia , Mononeuropatias/tratamento farmacológico , Neuralgia/tratamento farmacológico , Células do Corno Posterior/efeitos dos fármacos , Potenciais de Ação/fisiologia , Vias Aferentes/efeitos dos fármacos , Vias Aferentes/patologia , Vias Aferentes/fisiopatologia , Animais , Relação Dose-Resposta a Droga , Lateralidade Funcional/fisiologia , Mononeuropatias/patologia , Mononeuropatias/fisiopatologia , Neuralgia/patologia , Neuralgia/fisiopatologia , Medição da Dor/efeitos dos fármacos , Estimulação Física , Células do Corno Posterior/patologia , Células do Corno Posterior/fisiopatologia , Ratos , Ratos Sprague-Dawley , Tempo de Reação/efeitos dos fármacos , Tempo de Reação/fisiologiaRESUMO
Iontophoretically applied nociceptin (NC) was tested at different concentrations on the activity of spinal nociceptive specific (NS) and wide dynamic range (WDR) neurons. Low NC dosages inhibited the noxious response of NS neurons, higher dosages inhibited the noxious responses of the WDR neurons but had little effect on the non-noxious response. Naloxone did not antagonize the NC effect. Thus, appropriate dosages of NC may be selective, both for neuronal classes and for sensory modalities.
