Functional interactions between dentate gyrus, striatum and anterior thalamic nuclei on spatial memory retrieval

• Published in: Brain research Vol. 1605; pp. 59 - 69
• Main Authors: Méndez-Couz, M, Conejo, N.M, González-Pardo, H, Arias, J.L
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 24-04-2015
• Subjects: Animals; Anterior Thalamic Nuclei - physiology; Brain network; Corpus Striatum - physiology; Cytochrome c oxidase; Dentate gyrus; Dentate Gyrus - physiology; Electron Transport Complex IV; Extended hippocampal system; Hippocampus - physiology; Male; Maze Learning - physiology; Nerve Net - physiology; Neurology; Random Allocation; Rats; Rats, Wistar; Spatial Memory - physiology; Spatial memory retrieval; Thalamus; PAR; LM; Ce; dorsal striatum; medial prefrontal cortex; Cg; prelimbic cortex; M1; LS; entorhinal cortex; cytochrome c oxidase; parietal cortex; SuM; amygdala, basal nucleus; iinfralimbic cortex; PFC; DS; amygdala, medial nucleus; anterodorsal thalamic nucleus; premammillary nucleus; MD; Thalamus; CA3v; MM; RSA; AD; IL; Extended hippocampal system; amygdala, central nucleus; MS; Cornus Ammonis 1 of the dorsal hippocampus; PRh; RSG; AcSh; lateral septum; CA1d; mPFC; Dentate gyrus; Cornus Ammonis 3 of the ventral hippocampus; dorsal hippocampus; AV; Me; SMR; mediodorsal thalamic nucleus; AcC; DGd; Cornus Ammonis 3 of the dorsal hippocampus; Morris water maze; prefrontal cortex; Spatial memory retrieval; Naïve group; Ent; Medial septum; lateral nucleus of the mammillary bodies; N; DGv; R; retrosplenial agranular cortex; Cornus Ammonis 1 of the ventral hippocampus; CA1v; dentate gyrus of the ventral hippocampus; retrosplenial granular cortex; Ba; anteroventral thalamic nucleus; primary motor cortex; MWM; dH; supramammillary nucleus of the mammillary bodies; cingulate cortex; PrL; CO; medial nucleus of the mammillary bodies; perirhinal cortex; CA3d; Retrieval group; spatial reference memory; nucleus accumbens core; dentate gyrus of the dorsal hippocampus; PM; Brain network; nucleus accumbens shell; Cytochrome c oxidase
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2015.02.005

Abstract The standard model of memory system consolidation supports the temporal reorganization of brain circuits underlying long-term memory storage, including interactions between the dorsal hippocampus and extra-hippocampal structures. In addition, several brain regions have been suggested to be involved in the retrieval of spatial memory. In particular, several authors reported a possible role of the ventral portion of the hippocampus together with the thalamus or the striatum in the persistence of this type of memory. Accordingly, the present study aimed to evaluate the contribution of different cortical and subcortical brain regions, and neural networks involved in spatial memory retrieval. For this purpose, we used cytochrome c oxidase quantitative histochemistry as a reliable method to measure brain oxidative metabolism. Animals were trained in a hidden platform task and tested for memory retention immediately after the last training session; one week after completing the task, they were also tested in a memory retrieval probe. Results showed that retrieval of the previously learned task was associated with increased levels of oxidative metabolism in the prefrontal cortex, the dorsal and ventral striatum, the anterodorsal thalamic nucleus and the dentate gyrus of the dorsal and ventral hippocampus. The analysis of functional interactions between brain regions suggest that the dorsal and ventral dentate gyrus could be involved in spatial memory retrieval. In addition, the results highlight the key role of the extended hippocampal system, thalamus and striatum in this process. Our study agrees with previous ones reporting interactions between the dorsal hippocampus and the prefrontal cortex during spatial memory retrieval. Furthermore, novel activation patterns of brain networks involving the aforementioned regions were found. These functional brain networks could underlie spatial memory retrieval evaluated in the Morris water maze task.