Effect of excitatory and inhibitory agents and a glial inhibitor on optically-recorded primary-afferent excitation
Effect of excitatory and inhibitory agents and a glial inhibitor on optically-recorded primary-afferent excitation
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DOI：
10.1186/1744-8069-4-39
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发表时间：
2008-09-26
期刊：
影响因子：
3.3
通讯作者：
Murase, Kazuyuki
中科院分区：
文献类型：
--
作者：
Ikeda, Hiroshi;Kiritoshi, Takaki;Murase, Kazuyuki
通过用电压敏感染料对幼鼠脊髓片高阈值传入神经突触前兴奋进行成像，研究了GABA、兴奋性氨基酸受体拮抗剂和胶质细胞代谢抑制剂对脊髓背角初级传入兴奋的影响。初级传入纤维和终端顺行标记的电压敏感染料从背根连接到脊髓切片。单脉冲刺激C纤维激活强度的背根引起复合动作电位样的光学反应，在背角浅层。GABA（A）受体拮抗剂印防己毒素和荷包牡丹碱，谷氨酸受体拮抗剂D-AP 5和CNQX，以及神经胶质代谢抑制剂单氟乙酸（MFA）可增加诱发的突触前兴奋。在D-AP 5，CNQX和MFA的存在下，由印防己毒素引起的突触前兴奋的增加被抑制。兴奋性和抑制性氨基酸对精细初级传入神经中枢终末的突触前调制可能代表了调节疼痛传递的机制。
The effects of GABA, excitatory amino-acid receptors antagonists and a glial metabolism inhibitor on primary-afferent excitation in the spinal dorsal horn were studied by imaging the presynaptic excitation of high-threshold afferents in cord slices from young rats with a voltage-sensitive dye. Primary afferent fibers and terminals were anterogradely labeled with a voltage-sensitive dye from the dorsal root attached to the spinal cord slice. Single-pulse stimulation of C fiber-activating strength to the dorsal root elicited compound action potential-like optical responses in the superficial dorsal horn. The evoked presynaptic excitation was increased by the GABA(A) receptor antagonists picrotoxin and bicuculline, by glutamate receptor antagonists D-AP5 and CNQX, and by the glial metabolism inhibitor mono-fluoroacetic acid (MFA). The increase in presynaptic excitation by picrotoxin was inhibited in the presence of D-AP5, CNQX and MFA. Presynaptic modulation in the central terminal of fine primary afferents by excitatory and inhibitory amino acids may represent a mechanism that regulates the transmission of pain.