Woolf C J
Neurosci Lett. 1984 Mar 23;45(2):169-74. doi: 10.1016/0304-3940(84)90094-6.
The effect of naloxone on C-primary afferent-mediated inhibitions of C-fibre-evoked activity in deep dorsal horn neurons has been examined in decerebrate-spinal rats. The same C-afferents that evoke activity in a given neurone can inhibit that C-evoked activity (homosynaptic inhibition), and C-afferent input can also inhibit the activity evoked in dorsal horn neurones by other C-afferents (heterosynaptic inhibition). Naloxone was found to selectively reverse heterosynaptic C-mediated inhibitions without affecting homosynaptic inhibitions. In several neurones the heterosynaptic inhibitions were completely abolished by naloxone. These results show that homo- and heterosynaptic C-mediated inhibitions operate by different mechanisms and that, at least in some neurones, endogenous opioids are likely to be the major inhibitory transmitters involved in producing the heterosynaptic inhibition of the activity evoked by one C-input by another C-input.
在去大脑脊髓大鼠中，研究了纳洛酮对C类初级传入纤维介导的脊髓背角深层神经元C类纤维诱发活动抑制作用的影响。在给定神经元中引发活动的相同C类传入纤维可抑制该C类纤维诱发的活动（同突触抑制），并且C类传入纤维输入也可抑制其他C类传入纤维在背角神经元中诱发的活动（异突触抑制）。发现纳洛酮可选择性逆转异突触C类介导的抑制作用，而不影响同突触抑制作用。在几个神经元中，纳洛酮完全消除了异突触抑制作用。这些结果表明，同突触和异突触C类介导的抑制作用通过不同机制起作用，并且至少在某些神经元中，内源性阿片类物质可能是参与产生由一个C类输入对另一个C类输入诱发活动的异突触抑制作用的主要抑制性递质。
