201. Specific Deletion of the Astrocyte Leptin Receptor Induces Changes in Hippocampus Glutamate Metabolism, Synaptic Transmission and Plasticity.
- Author
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Naranjo V, Contreras A, Merino B, Plaza A, Lorenzo MP, García-Cáceres C, García A, Chowen JA, Ruiz-Gayo M, Del Olmo N, and Cano V
- Subjects
- Animals, Mice, Receptors, N-Methyl-D-Aspartate metabolism, Astrocytes metabolism, Hippocampus metabolism, Neuronal Plasticity, Receptors, Leptin genetics, Synaptic Transmission
- Abstract
The aim of this study was to indentify the involvement of leptin receptors (LepR) in astrocytes in hippocampal synaptic transmission and plasticity and metabolism. To this end we used a genetic mouse model (GFAP-LepR
-/- ) of specific LepR ablation in GFAP positive cells and recorded excitatory postsynaptic potentials (fEPSPs) within the CA1 area. Glutamate (Glu) uptake and the expression of Glu transporters (EEAT3, GLT-1 and GLAST) and enzymes involved in Glu metabolism (glutamine synthase, GABA decarboxylase 65 and 67) were quantified. Modifications in the expression of GFAP, the glucose transporter (GLUT)-1, and the monocarboxylate transporters MCT-2 and MCT-4, were also analyzed. The results show that depletion of LepR in GFAP positive cells reduced basal synaptic transmission within the CA1 area and impaired N-methyl-d-aspartate (NMDA)-evoked long-term depression (NMDA-LTD). Hippocampal slices from GFAP-LepR-/- mice displayed lower Glu uptake efficacy together with up-regulation of GLT-1, glutamine synthase, GFAP and GLUT-1. In conclusion, astrocyte LepRs are involved in the maintenance of Glu homeostasis and Glu neurotransmission within the hippocampus. Our findings support a role of hippocampal LepRs in synaptic plasticity, which could have an impact on memory and learning processes., (Copyright © 2019 IBRO. Published by Elsevier Ltd. All rights reserved.)- Published
- 2020
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