Overexpression of Serum Response Factor in Neurons Restores Ocular Dominance Plasticity in a Model of Fetal Alcohol Spectrum Disorders.
BACKGROUND
Deficits in neuronal plasticity underlie many neurobehavioral and cognitive problems presented in fetal alcohol spectrum disorder (FASD). Our laboratory has developed a ferret model showing that early alcohol exposure leads to a persistent disruption in ocular dominance plasticity (ODP). For instance, a few days of monocular deprivation results in a robust reduction of visual cortex neurons' responsiveness to stimulation of the deprived eye in normal animals, but not in ferrets with early alcohol exposure. Previously our laboratory demonstrated that overexpression of serum response factor (SRF) exclusively in astrocytes can improve neuronal plasticity in FASD. Here, we test whether neuronal overexpression of SRF can achieve similar effects.


METHODS
Ferrets received 3.5 g/kg alcohol intraperitoneally (25% in saline) or saline as control every other day between postnatal day 10 to 30, which is roughly equivalent to the third trimester of human gestation. Animals were given intracortical injections of a Herpes Simplex Virus-based vector to express either green fluorescent protein or a constitutively active form of SRF in infected neurons. They were then monocularly deprived by eyelid suture for 4 to 5 days after which single-unit recordings were conducted to determine whether changes in ocular dominance had occurred.


RESULTS
Overexpression of a constitutively active form of SRF by neurons restored ODP in alcohol-treated animals. This effect was observed only in areas near the site of viral infection.


CONCLUSIONS
Overexpression of SRF in neurons can restore plasticity in the ferret model of FASD, but only in areas near the site of infection. This contrasts with SRF overexpression in astrocytes which restored plasticity throughout the visual cortex.
Department of Pediatrics (WAF, AEM), University of Maryland, Baltimore, Maryland.
W Alex
WA
Foxworthy
Department of Pediatrics (WAF, AEM), University of Maryland, Baltimore, Maryland.
Alexandre E
AE
Medina
D000818:Animals; D030801:Animals, Genetically Modified; D004195:Disease Models, Animal; D023882:Dominance, Ocular / Q000502:physiology*; D000431:Ethanol / Q000009:adverse effects*; D005289:Ferrets; D063647:Fetal Alcohol Spectrum Disorders / Q000378:metabolism / Q000503:physiopathology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D026362:Serum Response Factor / Q000096:biosynthesis*; D014793:Visual Cortex / Q000503:physiopathology
D026362:Serum Response Factor; D000431:Ethanol
Fetal Alcohol Syndrome; Monocular Deprivation; Ocular Dominance; Serum Response Factor; Visual Development