Publicover S J
School of Biological Sciences, University of Birmingham, Edgbaston, UK.
Exp Brain Res. 1991;84(3):680-4. doi: 10.1007/BF00230983.
Rat hippocampal slices were exposed briefly (12-15 min) to AlF4- (10 mmol/l NaF, 10 mumol/l AlCl3). The effect on synaptic transmission in area CAl was measured using extracellular electrodes placed in the stratum pyramidale and stratum radiatum. During fluoride exposure, both spike and EPSP amplitude fell to very low levels. Upon washout, spike amplitude recovered beyond control values, and in half of the preparations a prolonged enhancement of spike amplitude (greater than 2 h) occurred. Similar modulation of EPSP slope indicated that these charges were primarily synaptic. If Al3+ was omitted from the F(-)-containing saline, enhancement of spike amplitude, when observed, was brief (20-30 min) and no enhancement of EPSP slope was seen. Omission of Ca2+ from the AlF(4-)-containing saline also abolished any long-lasting enhancement of synaptic transmission, though population spike amplitude in most slices showed a brief (20-30 min) stimulatory response. In preparations in which LTP had previously been saturated, synaptic transmission was not enhanced by exposure to AlF4-. It is concluded that NaF/ACl3 exposure induces an LTP-like process by G-protein activation, which involves recruitment of processes involved in LTP, possibly including an enhancement of Ca(2+)-influx.
将大鼠海马切片短暂暴露于AlF4-（10 mmol/l NaF，10 μmol/l AlCl3）中12 - 15分钟。使用置于锥体层和辐射层的细胞外电极测量对CAl区突触传递的影响。在氟化物暴露期间，峰电位和兴奋性突触后电位（EPSP）幅度均降至非常低的水平。洗脱后，峰电位幅度恢复到对照值以上，并且在一半的制备物中出现了峰电位幅度的长时间增强（超过2小时）。EPSP斜率的类似调节表明这些变化主要是突触性的。如果从含氟盐溶液中省略Al3+，观察到的峰电位幅度增强是短暂的（20 - 30分钟），并且未观察到EPSP斜率的增强。从含AlF4-的盐溶液中省略Ca2+也消除了突触传递的任何持久增强，尽管大多数切片中的群体峰电位幅度显示出短暂的（20 - 30分钟）刺激反应。在先前LTP已饱和的制备物中，暴露于AlF4-不会增强突触传递。结论是，NaF/AlCl3暴露通过G蛋白激活诱导类似LTP的过程，这涉及募集LTP相关的过程，可能包括Ca2+内流的增强。
