Kessal Karima, Chessel Aline, Spennato Guillaume, Garcia René
Institut National de la Santé et de la Recherche Médicale, Equipe Avenir, Nice, France.
Synapse. 2005 Jul;57(1):61-5. doi: 10.1002/syn.20154.
Excitatory glutamatergic fibers from limbic structures, such as the hippocampus and the basolateral amygdala, are known to converge on the same neurons in the nucleus accumbens. We have recently shown that ketamine, at a dose (25 mg/kg) that produces psychosis-like behaviors in rats, decreases glutamatergic transmission between the hippocampus and the nucleus accumbens. Here we investigated whether ketamine also affects glutamatergic transmission between the basolateral amygdala and the nucleus accumbens. We also studied the effects of amphetamine (1.5 mg/kg), known to evoke psychosis-like behaviors in rats. We found that each drug produced a long-lasting (at least 30 min) potentiation of synaptic efficacy in the projection from the basolateral amygdala to the nucleus accumbens. However, while this synaptic potentiation developed shortly after ketamine injection (within 4 min), it occurred after a 30-min delay in rats injected with amphetamine. These data reveal, in freely behaving rats, that ketamine has a more rapid and powerful effect on projection targets of the basolateral amygdala than does amphetamine.
来自边缘结构（如海马体和基底外侧杏仁核）的兴奋性谷氨酸能纤维已知会汇聚于伏隔核中的同一神经元。我们最近发现，氯胺酮以能在大鼠中产生类似精神病行为的剂量（25毫克/千克），会降低海马体与伏隔核之间的谷氨酸能传递。在此，我们研究了氯胺酮是否也会影响基底外侧杏仁核与伏隔核之间的谷氨酸能传递。我们还研究了已知能在大鼠中诱发类似精神病行为的苯丙胺（1.5毫克/千克）的作用。我们发现，每种药物都会使从基底外侧杏仁核到伏隔核的投射中的突触效能产生持久（至少30分钟）增强。然而，虽然这种突触增强在氯胺酮注射后不久（4分钟内）就出现了，但在注射苯丙胺的大鼠中，它在30分钟延迟后才出现。这些数据表明，在自由活动的大鼠中，氯胺酮对基底外侧杏仁核投射靶点的作用比苯丙胺更快、更强。
