Disruption of hippocampal CA3 network: effects on episodic‐like memory processing in C57BL/6J mice

• DOI: 10.1111/j.1460-9568.2004.03484.x
• Publication Date: 2004-07-02T14:27:14Z
• Authors: Stéphanie Daumas; Hélène Halley; Jean‐Michel Lassalle
• Keywords: Male; 570; Behavior, Animal; [SCCO.NEUR]Cognitive science/Neuroscience; [SCCO.NEUR] Cognitive science/Neuroscience; Conditioning, Classical; Spatial Behavior; Fear; Hippocampus; Discrimination Learning; Mice, Inbred C57BL; Mice; Zinc; 03 medical and health sciences; 0302 clinical medicine; Memory; Animals; Nerve Net; Chelating Agents

AbstractLesion studies have demonstrated the prominent role of the hippocampus in spatial and contextual learning. To better understand how contextual information is processed in the CA3 region during learning, we focused on the CA3 autoassociative network hypothesis. We took advantage of a particularity of the mossy fibre (MF) synapses, i.e. their high zinc concentration, to reversibly disrupt the afferent MF pathway by microinfusions of an intracellular (DEDTC) or an extracellular (CaEDTA) zinc chelator into the CA3 area of the dorsal hippocampus of mice. Disruption of the CA3 network significantly impaired the acquisition and the consolidation of contextual fear conditioning, whereas contextual retrieval was unaffected. These results also suggest a heterogeneity between the cognitive processes underlying spatial and contextual memory that might be linked to the specific involvement of free zinc in contextual information processing.