title: Androgen Modulation of Hippocampal Structure and Function.
abstract: Androgens have profound effects on hippocampal structure and function, including induction of spines and spine synapses on the dendrites of CA1 pyramidal neurons, as well as alterations in long-term synaptic plasticity (LTP) and hippocampally dependent cognitive behaviors. How these effects occur remains largely unknown. Emerging evidence, however, suggests that one of the key elements in the response mechanism may be modulation of brain-derived neurotrophic factor (BDNF) in the mossy fiber (MF) system. In male rats, orchidectomy increases synaptic transmission and excitability in the MF pathway. Testosterone reverses these effects, suggesting that testosterone exerts tonic suppression on MF BDNF levels. These findings suggest that changes in hippocampal function resulting from declining androgen levels may reflect the outcome of responses mediated through normally balanced, but opposing, mechanisms: loss of androgen effects on the hippocampal circuitry may be compensated, at least in part, by an increase in BDNF-dependent MF plasticity.
authors.affiliation: Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Sarah
authors.initials: S
authors.lastname: Atwi
authors.affiliation: Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Dallan
authors.initials: D
authors.lastname: McMahon
authors.affiliation: The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA Department of Child & Adolescent Psychiatry, Physiology & Neuroscience, and Psychiatry, New York University Langone Medical Center, New York, NY, USA.
authors.forename: Helen
authors.initials: H
authors.lastname: Scharfman
authors.affiliation: Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada nmaclusk@uoguelph.ca.
authors.forename: Neil J
authors.initials: NJ
authors.lastname: MacLusky
mesh_terms: D000728:Androgens / Q000378:metabolism*; D000818:Animals; D006624:Hippocampus / Q000033:anatomy & histology* / Q000502:physiology* / Q000503:physiopathology; D006801:Humans
chemical_list: D000728:Androgens
keywords: BDNF; CA3; hippocampus; mossy fibers; testosterone