Rbah Latifa, Leviel Vincent, Zimmer Luc
CERMEP Biomedical Cyclotron, 59 boulevard Pinel, F-69003 Lyon, France.
Synapse. 2003 Sep 15;49(4):239-45. doi: 10.1002/syn.10235.
The effects of the electrically evoked serotonin release were evaluated on the binding of (18)F-MPPF in the hippocampus of anesthetized rats. The specific binding of (18)F-MPPF was measured by an implanted beta-microprobe and the serotonin (5-HT) extracellular concentration was measured by microdialysis under the same conditions. Our results showed that the 10-, 20-, or 30-min electrical stimulation of the raphe nucleus elicited a significant increase in extracellular 5-HT, only detectable in the presence of a 5-HT reuptake inhibitor in the perfusate (5 microM clomipramine). Interestingly, the raphe stimulations were associated with a 27-76% reversible decrease of the (18)F-MPPF specific binding in the hippocampus, but an unchanged extracellular (18)F-MPPF collected in dialysates. Considered together, these observations suggest that (18)F-MPPF binding is sensitive to 5-HT released at a neuronal level. This compartment, explored by the beta-microprobe, is probably distinct from the extracellular compartment, explored by microdialysis.
在麻醉大鼠的海马体中，评估电诱发血清素释放对（18）F-MPPF结合的影响。通过植入的β-微探针测量（18）F-MPPF的特异性结合，并在相同条件下通过微透析测量血清素（5-HT）的细胞外浓度。我们的结果表明，对中缝核进行10、20或30分钟的电刺激会引起细胞外5-HT显著增加，只有在灌注液中存在5-HT再摄取抑制剂（5 microM氯米帕明）时才能检测到。有趣的是，中缝核刺激与海马体中（18）F-MPPF特异性结合的27-76%可逆性降低相关，但透析液中收集的细胞外（18）F-MPPF未发生变化。综合考虑，这些观察结果表明，（18）F-MPPF结合对神经元水平释放的5-HT敏感。通过β-微探针探索的这个隔室可能与通过微透析探索的细胞外隔室不同。
