17α Estradiol promotes plasticity of spared inputs in the adult amblyopic visual cortex

Abstract

The promotion of structural and functional plasticity by estrogens is a promising therapy to enhance central nervous system function in the aged. However, how the sensitivity to estrogens is regulated across brain regions, age and experience is poorly understood. To ask if estradiol treatment impacts structural and functional plasticity in sensory cortices, we examined the acute effect of 17α Estradiol in adult Long Evans (LE) rats following chronic monocular deprivation, a manipulation that reduces the strength and selectivity of deprived eye vision. Chronic monocular deprivation decreased thalamic input from the deprived eye to the binocular visual cortex and accelerated short-term depression of the deprived eye pathway, without changing the total density of excitatory synapses. Importantly, we found that the classical estrogen receptors ERα and ERβ are robustly expressed in the adult visual cortex, and that a single dose of 17α Estradiol increased the size of excitatory postsynaptic densities, reduced the expression of parvalbumin and decreased the integrity of the extracellular matrix. Furthermore, 17α Estradiol enhanced experience-dependent plasticity in the amblyopic visual cortex, and promoted response potentiation of the pathway served by the non-deprived eye. The promotion of plasticity at synapses serving the non-deprived eye may reflect selectivity for synapses with an initially low probability of neurotransmitter release, and may inform applications to remap spared inputs around a scotoma or a cortical infarct 4 Materials and Methods: Subjects Long Evans (LE) Rats (strain 006, RRID:RGD_2308852) were purchased from Charles River Laboratories (Raleigh, NC). Equal numbers of adult (>postnatal day 180, >P180) males and females were used. Animals were raised in 12/12 hour light/dark cycle and experiments were performed, or subjects were sacrificed, 6 hours into the light phase. Brains from 8-12 week old female ERβ -/rats were provided by M.A. Karim Rumi of the University of Kansas Medical Center 39 . All procedures were approved by the University of Maryland Institutional Animal Care and Use Committee and were carried out in accordance with the Guide for the Care and Use of Laboratory Animals. Monocular deprivationP14 LE rat pups were anesthetized with ketamine/xylazine (100 mg/10 mg/kg, intraperitoneal).

Diabetic Neovascularization Defects in the Retina Are Improved by Genistein Supplementation in the Ovariectomized Rat

“…Recent studies emphasize the protective effect of estrogen in maintaining visual health in women, especially in menopause. The presence of estrogen receptors in the retina, lens, cornea, and iris is an actual reason for this claim (Feola et al, 2019, Sengupta et al, 2019.…”