title: Dietary cholesterol concentration affects synaptic plasticity and dendrite spine morphology of rabbit hippocampal neurons.
abstract: Previous studies have shown dietary cholesterol can enhance learning but retard memory which may be partly due to increased cholesterol levels in hippocampus and reduced afterhyperpolarization (AHP) amplitude of hippocampal CA1 neurons. This study explored the dose-dependent effect of dietary cholesterol on synaptic plasticity of rabbit hippocampal CA1 neurons and spine morphology, the postsynaptic structures responsible for synaptic plasticity. Field potential recordings revealed a low concentration of dietary cholesterol increased long-term potentiation (LTP) expression while high concentrations produced a pronounced reduction in LTP expression. Dietary cholesterol facilitated basal synaptic transmission but did not influence presynaptic function. DiI staining showed dietary cholesterol induced alterations in dendrite spine morphology characterized by increased mushroom spine density and decreased thin spine density, two kinds of dendritic spines that may be linked to memory consolidation and learning acquisition. Dietary cholesterol also modulated the geometric measures of mushroom spines. Therefore, dietary cholesterol dose-dependently modulated both synaptic plasticity and dendrite spine morphologies of hippocampal CA1 neurons that could mediate learning and memory changes previously seen to result from feeding a cholesterol diet.
authors.affiliation: Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, WV 26506, United States of America; Blanchette Rockefeller Neurosciences Institute, Morgantown, WV 26505, United States of America. Electronic address: dswang@hsc.wvu.edu.
authors.forename: Desheng
authors.initials: D
authors.lastname: Wang
authors.affiliation: Blanchette Rockefeller Neurosciences Institute, Morgantown, WV 26505, United States of America.
authors.forename: Wen
authors.initials: W
authors.lastname: Zheng
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal / Q000166:cytology* / Q000502:physiology*; D002791:Cholesterol, Dietary; D049229:Dendritic Spines / Q000502:physiology*; D004032:Diet; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D008297:Male; D018613:Microscopy, Confocal; D009473:Neuronal Plasticity / Q000502:physiology*; D011817:Rabbits; D009435:Synaptic Transmission / Q000502:physiology*; D046509:Tissue Culture Techniques
chemical_list: D002791:Cholesterol, Dietary
keywords: Cholesterol; Dendritic spine; Hippocampus; Morphology; Synaptic plasticity