del Olmo Nuria, Miguéns Miguel, Higuera-Matas Alejandro, Torres Isabel, García-Lecumberri Carmen, Solís José María, Ambrosio Emilio
Departamento de Psicobiología, Facultad de Psicología, Universidad Nacional de Educación a Distancia (UNED), C/Juan del Rosal no 10, 28040 Madrid, Spain.
Brain Res. 2006 Oct 20;1116(1):120-6. doi: 10.1016/j.brainres.2006.07.001. Epub 2006 Sep 18.
Drug addiction may involve learning and memory processes requiring the participation of hippocampal formation. One of the best studied examples of hippocampal synaptic plasticity is the long-term potentiation (LTP) which usually occurs when hippocampal synapses are stimulated with high-frequency stimulation. The aim of this work has been to study the effect of extinction of cocaine self-administration behavior on synaptic plasticity in rat hippocampal slices. LTP was induced using a tetanization paradigm consisting of a single train of high-frequency (100 Hz) stimulation for one second. This tetanization protocol evoked a greater and more perdurable LTP in slices obtained after 10 days of extinction of cocaine self-administration (1 mg/kg/injection) than that elicited in slices from saline self-administering (0.9% NaCl) animals. In addition, this LTP facilitation in animals which have followed the cocaine self-administration extinction protocol was very similar to that obtained in slices from cocaine self-administering animals. These results suggest that chronic cocaine self-administration induces enduring neuroadaptive changes in hippocampal synaptic plasticity which last even after the extinction of this behavior and that they may be involved in cocaine dependence.
药物成瘾可能涉及需要海马结构参与的学习和记忆过程。海马突触可塑性研究得最为充分的例子之一是长时程增强（LTP），它通常在高频刺激海马突触时出现。这项工作的目的是研究可卡因自我给药行为消退对大鼠海马切片突触可塑性的影响。使用由一列高频（100Hz）刺激持续一秒组成的强直刺激范式诱导LTP。与盐水自我给药（0.9%NaCl）动物的切片相比，在可卡因自我给药（1mg/kg/注射）消退10天后获得的切片中，这种强直刺激方案诱发了更大且更持久的LTP。此外，遵循可卡因自我给药消退方案的动物中的这种LTP促进作用与可卡因自我给药动物的切片中获得的非常相似。这些结果表明，慢性可卡因自我给药会在海马突触可塑性中诱导持久的神经适应性变化，即使这种行为消退后这些变化仍然存在，并且它们可能与可卡因依赖有关。
