ENDOMORPHIN-1 IS MORE POTENT THAN ENDOMORPHIN-2 IN INHIBITION OF SYNAPTIC TRANSMISSION IN SUBSTANTIA GELATINOSA OF ADULT RAT SPINAL CORD / 神经解剖学杂志
Chinese Journal of Neuroanatomy
; (6): 269-275, 2005.
Article
en Zh
| WPRIM
| ID: wpr-409875
Biblioteca responsable:
WPRO
ABSTRACT
Effects of endomorphin-1 (EM-1) and endomorphin-2 (EM-2) on synaptic transmission were investigated on neurons in substantia gelatinosa (SG) of the spinal dorsal horn by whole-cell voltage clamp recording. Both EM-1 (1 μmol/L) and EM-2 (1 μmol/L)remarkably reduced the frequency but not the amplitude of miniature excitatory postsynaptic currents (mEPSCs) and miniature inhibitory postsynaptic currents (mIPSCs). These effects were antagonized by 3-funaltrexamine ( β-FNA, 10 μmol/L), a selective μ-opioid receptor antagonist. Noticeably, EM-1 showed higher potency in decreasing the frequency of mEPSCs and mIPSCs than that of EM-2. These results indicate that EMs suppress both excitatory and inhibitory synaptic transmission by activating presynaptic μ-opioid receptors in the SG and EM-1, compared with EM-2, might be a more potent endogenous analgesic at the spinal cord level.
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Índice:
WPRIM
Idioma:
Zh
Revista:
Chinese Journal of Neuroanatomy
Año:
2005
Tipo del documento:
Article