Relationship between meso-hippocampal dopaminergic projections and hippocampal P300-like potentials in rats

AIM: To evaluate the role of the meso-hippocampal dopaminergic systems in the generation of hippocampal P300-like potentials. METHODS: Changes of ventral hippocampal P300-like potentials were examined after lesions of the meso-hippocampal dopaminergic systems.The extracellular DA and DOPAC were collected by the push-pull method in the ventral and dorsal hippocampus and their contents were measured by high-performance liquid chromatography with electrochemical detection(HPLC-EC). RESULTS: The contents of DA and DOPAC in the ventral hippocampus were higher than those in the dorsal hippocampus in the normal animals. The peak latencies of P300-like potentials were prolonged and the contents of DA and DOPAC decreased in the ventral hippocampi after lesions of the meso-hippocampal dopaminergic systems. CONCLUSIONS: There exist meso-hippocampal dopaminergic systems in rats;The meso-hippocampal dopaminergic terminals is mainly located in the ventral hippocampal area in rats; The meso-hippocampal dopaminergic projections take part in the generation of the hippocampal P300-like potentials in rats.