Non-exocytotic GABA overflow in rat striatum inhibits gnawing.
Non-exocytotic GABA overflow in rat striatum inhibits gnawing.
复制标题
大鼠纹状体中的非胞吐 GABA 溢出抑制了啃咬。
DOI：
10.1016/s0024-3205(97)00738-8
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发表时间：
1997
期刊：
影响因子：
6.1
通讯作者：
Ungerstedt,U
中科院分区：
文献类型：
--
作者：
Drew,KL;Fitka,T;Hu,Y;Ungerstedt,U
本研究验证了大鼠前纹状体自发γ-氨基丁酸（GABA）外排与细胞内和细胞外钙无关的假设；2)与生理相关。用体内微透析法从清醒、自由活动的大鼠纹状体中提取细胞外多巴胺（DA）和GABA。虽然透析液中DA的浓度是GABA的2到3倍，并且通过去除钙降低了至少70%，但即使在EGTA或细胞内钙螯合剂APTRA-AM存在的情况下，GABA也不受影响。通过将GABA合成抑制剂3-巯基丙酸（3-MPA）注入纹状体，并测量其对行为和GABA灌注浓度的后续影响，研究了GABA非胞外池的功能意义。结果表明，3-MPA增加了啃食行为，表明基底非胞外GABA溢出正常起抑制啃食的作用。
The present study tested the hypotheses that spontaneous γ-aminobutyric acid (GABA) efflux in anterior rat striatum is 1) independent of intra- and extracellular calcium; and 2) is physiologically relevant. Extracellular dopamine (DA) and GABA were sampled from striatum of awake, freely moving rats using in vivo microdialysis. Although dialysate concentrations of DA were 2 to 3 times greater than GABA and were decreased by at least 70% by removal of calcium, GABA was unaffected even in the presence of EGTA or the intracellular calcium chelator APTRA-AM. Functional significance of this non-exocytotic pool of GABA was tested by injecting 3-mercaptopropionic acid (3-MPA), an inhibitor of GABA synthesis, into the striatum via a guide cannula sidled alongside a microdialysis probe and measuring subsequent effects on behavior and perfusate concentrations of GABA. Results show that 3-MPA increases gnawing behavior suggesting that basal, non-exocytotic GABA overflow normally functions to suppress gnawing.