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Sousa MS, Alves JL, Freitas JCS, Miraldo JN, Sampaio Dos Aidos FDS, Santos RM, Rosário LM, Quinta-Ferreira RM, Quinta-Ferreira ME, Matias CM. A model of zinc dynamics evoked by intense stimulation at the cleft of hippocampal mossy fiber synapses. Brain Res 2023; 1807:148322. [PMID: 36906226 DOI: 10.1016/j.brainres.2023.148322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 02/28/2023] [Accepted: 03/06/2023] [Indexed: 03/12/2023]
Abstract
Zinc is a transition metal that is particularly abundant in the mossy fibers of the hippocampal CA3 area. Despite the large number of studies about the zinc role in mossy fibers, the action of zinc in synaptic mechanisms is only partly known. The use of computational models can be a useful tool for this study. In a previous work, a model was developed to evaluate zinc dynamics at the mossy fiber synaptic cleft, following weak stimulation, insufficient to evoke zinc entry into postsynaptic neurons. For intense stimulation, cleft zinc effluxes must be considered. Therefore, the initial model was extended to include postsynaptic zinc effluxes based on the Goldman-Hodgkin-Katz current equation combined with Hodgkin and Huxley conductance changes. These effluxes occur through different postsynaptic escape routes, namely L- and N-types voltage-dependent calcium channels and NMDA receptors. For that purpose, various stimulations were assumed to induce high concentrations of cleft free zinc, named as intense (10 μM), very intense (100 μM) and extreme (500 μM). It was observed that the main postsynaptic escape routes of cleft zinc are the L-type calcium channels, followed by the NMDA receptor channels and by N-type calcium channels. However, their relative contribution for cleft zinc clearance was relatively small and decreased for higher amounts of zinc, most likely due to the blockade action of zinc in postsynaptic receptors and channels. Therefore, it can be concluded that the larger the zinc release, the more predominant the zinc uptake process will be in the cleft zinc clearance.
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Affiliation(s)
- Marta S Sousa
- Department of Physics, University of Coimbra, P-3004-516 Coimbra, Portugal; ESS-IPP - Superior School of Health - Polytechnic Institute of Porto, P-4200-072 Porto, Portugal; CNC- Center for Neuroscience and Cell Biology, University of Coimbra, P-3004-504 Coimbra, Portugal
| | - João L Alves
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, P-3004-504 Coimbra, Portugal; Department of Life Sciences, University of Coimbra, P-3004-516 Coimbra, Portugal
| | | | - João N Miraldo
- Department of Civil Engineering, University of Coimbra, P-3030-790 Coimbra, Portugal
| | - Fernando D S Sampaio Dos Aidos
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, P-3004-504 Coimbra, Portugal; CFisUC, Department of Physics, University of Coimbra, P-3004-516 Coimbra, Portugal
| | - Rosa M Santos
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, P-3004-504 Coimbra, Portugal; Department of Life Sciences, University of Coimbra, P-3004-516 Coimbra, Portugal
| | - Luís M Rosário
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, P-3004-504 Coimbra, Portugal; Department of Life Sciences, University of Coimbra, P-3004-516 Coimbra, Portugal
| | - Rosa M Quinta-Ferreira
- CIEPQPF - Research Centre of Chemical Process Engineering and Forest Products, Department of Chemical Engineering, University of Coimbra, P-3030-790 Coimbra, Portugal
| | - M Emília Quinta-Ferreira
- Department of Physics, University of Coimbra, P-3004-516 Coimbra, Portugal; CNC- Center for Neuroscience and Cell Biology, University of Coimbra, P-3004-504 Coimbra, Portugal
| | - Carlos M Matias
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, P-3004-504 Coimbra, Portugal; Dept. of Physics, UTAD- University of Trás-os-montes and Alto Douro, P-5000-801 Vila Real, Portugal.
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