Original Research ARTICLE
TRICLOSAN IMPAIRS HIPPOCAMPAL SYNAPTIC PLASTICITY AND SPATIAL MEMORY IN MALE RATS
- 1Instituto de Neurociencia Biomédica, Facultad de Medicina, Universidad de Chile, Chile
- 2Centro Integrativo de Biología y Química Aplicada, Universidad Bernardo O’Higgins, Chile
- 3Instituto de Ciencias Biomédicas, Universidad de Chile, Chile
- 4Instituto de Ciencias Biomédicas, Universidad de Chile, Chile
- 5Department of Neuroscience, Faculty of Medicine, University of Chile, Chile
- 6Facultad de Medicina, Diego Portales Universität, Chile
- 7Centro de Estudios Moleculares de la Célula, Facultad de Medicina, Universidad de Chile, Chile
Triclosan, a widely used industrial and household agent, is present as an antiseptic ingredient in numerous products of everyday use, such as toothpaste, cosmetics, kitchenware and toys. Previous studies have shown that human brain and animal tissues contain triclosan, which has been found also as a contaminant of water and soil. Triclosan disrupts heart and skeletal muscle calcium signaling, damages liver function, alters gut microbiota, causes colonic inflammation, and promotes apoptosis in cultured neocortical neurons and neural stem cells. Information, however, on the possible effects of triclosan on the function of the hippocampus, a key brain region for spatial learning and memory, is lacking. Here, we report that triclosan addition at low concentrations to hippocampal slices from male rats inhibited long-term potentiation but did not affect basal synaptic transmission or paired-pulse facilitation, and modified the content or phosphorylation levels of synaptic plasticity-related proteins. Additionally, incubation of primary hippocampal cultures with triclosan prevented both the dendritic spine remodeling induced by brain-derived neurotrophic factor and the emergence of spontaneous oscillatory calcium signals. Furthermore, intra-hippocampal injection of triclosan significantly disrupted rat navigation in the Oasis maze spatial memory task, an indication that triclosan impairs hippocampus-dependent spatial memory performance. Based on these combined results, we conclude that triclosan exerts highly damaging effects on hippocampal neuronal function in vitro and impairs spatial memory processes in vivo.
Keywords: Hippocampus, structural plasticity, calcium signals, Synaptic Transmission, Antimicrobial agents
Received: 18 Jul 2018;
Accepted: 05 Nov 2018.
Edited by:Victor Ramírez-Amaya, Instituto de Investigación Médica Mercedes y Martín Ferreyra (INIMEC), Argentina
Reviewed by:Almira Vazdarjanova, Augusta University, United States
Jean-Pascal Morin, National Autonomous University of Mexico, Mexico
Copyright: © 2018 Arias-Cavieres, More, Vicente, Adasme, Hidalgo, Valdes, Humeres, Valdes-Undurraga, Sanchez, Barrientos and Hidalgo. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Genaro C. Barrientos, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile, email@example.com