Effects of CGRP on synaptic transmissions in spinal cord motoneuron in vitro
Objective:To in vitro observe the effects of calcitonin gene-related peptide(CGRP)on synaptic transmissions in the spinal cord motoneuron(MN)of neonatal rat.Methods:Neonatal SD rats,aged 8 to 12 days,were selected to prepare transverse spinal cord slices.Intracellular recording was performed from MN in the ventral horn of the spinal cord slices,and stimulation(monopulse,0.1 to 0.2 ms,0.1 Hz,10 to 100 V)was applied to the ipsilateral ventrolateral funiculus(iVLF)and ipsilateral dorsal root(iDR)to induce excitatory postsynaptic potentials(iVLF-EPSP and iDR-EPSP).CGRP was perfused to observe its effects on the synaptic transmissions in spinal cord MN.Results:① In 7 stably recorded MN,iVLF-EPSP was evoked and 1 µmol/L CGRP was perfused for 15 min.Inhibitory effect on duration of iVLF-EPSP was observed in 5 MN(P＜0.05);② In 5 stably recorded MN,iDR-EPSP was evoked and 1 μmol/L CGRP was perfused for 15 min.Inhibitory effect on area under curve(P＜0.05)and raise time(P＜0.01)of iDR-EPSP was observed in 3 MN;③ In 2 stably recorded MN,the amplitude of iDR-EPSP was decreased after perfusion with 1 and 5 μmol/L CGRP respectively for 15 min,with the inhibition rates of 6％and 36％,respectively.Conclusion:CGRP may produce inhibitory effects on MN synaptic transmissions from descending activation and sensory afferent input pathways.
万方数据
维普
