Warner R L, Johnston C, Hamilton R, Skolnick M H, Wilson O B
Department of Anatomical Sciences, University of Texas Health Science Center, Houston Dental Branch.
Life Sci. 1994;54(7):481-90. doi: 10.1016/0024-3205(94)00407-2.
A specific form of Transcranial Electrostimulation Treatment (TCET) has been shown to induce analgesia, alleviate symptoms of opiate withdrawal and alter nociceptive responses in neurons in the midbrain and hypothalamus of rats. TCET consists of a 10Hz, charge balanced, 10 mu A current passed for 30 minutes between electrodes placed in the ears. Both serotonin (5HT) and endogenous opioids have been strongly implicated in TCET responses. This study directly measured brain levels of several neurotransmitters and their metabolites in anesthetized rats stimulated with either 10 mu A TCET or 0 mu A (Sham). Neurotransmitters measured in selected homogenized brain areas by high performance liquid chromatography were 5HT and its metabolite, 5-hydroxyindolacetic acid (5HIAA); norepinephrine (NE) and its metabolite, 3-methoxy-4-hydroxyphenethyleneglycol (MHPG); and dopamine (DA). Levels of NE and DA were significantly higher in the hypothalamic region of TCET rats than of control rats. The midbrains of TCET rats contained significantly elevated levels of DA, MHPG, 5HT and 5HIAA. In the hindbrain no significant differences were observed. Thus, TCET appears to cause an increase in the synthesis or release of 5HT, DA and NE in the midbrain and DA and 5HT in the hypothalamus. In a separate experiment, beta-endorphin-like immunoreactivity was measured in blood plasma taken from rats at intervals before, during and after a 30 minute TCET treatment, but no demonstrable TCET effect was observed. The lack of change in serum endorphin levels suggests that TCET-induced opioid activity may be confined to the central nervous system, a reasonable theory because the current passes only through the head.
一种特定形式的经颅电刺激治疗（TCET）已被证明可诱导镇痛、减轻阿片类药物戒断症状，并改变大鼠中脑和下丘脑神经元的伤害性反应。TCET包括在置于耳部的电极之间通过10Hz、电荷平衡、10μA的电流，持续30分钟。血清素（5HT）和内源性阿片类物质都与TCET反应密切相关。本研究直接测量了用10μA TCET或0μA（假刺激）刺激的麻醉大鼠中几种神经递质及其代谢产物的脑内水平。通过高效液相色谱法在选定的匀浆脑区测量的神经递质有5HT及其代谢产物5-羟吲哚乙酸（5HIAA）；去甲肾上腺素（NE）及其代谢产物3-甲氧基-4-羟基苯乙二醇（MHPG）；以及多巴胺（DA）。TCET大鼠下丘脑区域的NE和DA水平显著高于对照大鼠。TCET大鼠的中脑含有显著升高的DA、MHPG、5HT和5HIAA水平。在后脑中未观察到显著差异。因此，TCET似乎会导致中脑内5HT、DA和NE以及下丘脑内DA和5HT的合成或释放增加。在另一个实验中，在30分钟TCET治疗前、治疗期间和治疗后的不同时间间隔，测量了大鼠血浆中的β-内啡肽样免疫反应性，但未观察到明显的TCET效应。血清内啡肽水平缺乏变化表明，TCET诱导的阿片类活性可能局限于中枢神经系统，这是一个合理的理论，因为电流仅通过头部。
