Prenatal ethanol exposure in rats decreases levels of complexin proteins in the frontal cortex.
BACKGROUND
Rodents that are prenatally exposed to ethanol have been shown to exhibit a wide range of cognitive deficits, including impairments in memory, attention and executive function. To determine a potential molecular substrate for cognitive dysfunction in adulthood, we measured regional levels of the presynaptic proteins complexin I and II in a rat model of prenatal ethanol exposure, as levels of these proteins are altered in cognitive-related synaptic plasticity.


METHODS
Pregnant female rats received either a liquid ethanol diet (36% ethanol-derived calories) or a liquid control diet (maltose-dextrin isocalorically substituted for ethanol, matched in amount [g/kg body wt/day of gestation] to an ethanol-consuming partner), or were given ad libitum-fed access to standard laboratory chow and water. Levels of complexin I, II and the ubiquitous presynaptic marker synaptophysin were measured in the frontal cortex and hippocampus of adult male offspring, using ELISA.


RESULTS
Prenatal exposure to ethanol did not alter levels of presynaptic proteins in the hippocampus or levels of synaptophysin in the prefrontal cortex. However, rats prenatally exposed to ethanol displayed significantly lower levels of both complexin I and II in the prefrontal cortex compared to control animals.


CONCLUSIONS
These data indicate that prenatal exposure to ethanol is associated with a selective loss of complexin proteins in the frontal cortex. These proteins are known to be important for activity-dependent neurotransmission, and have previously been shown to mediate synaptic plasticity and cognition. These combined findings suggest that further study of complexin proteins as a substrate for cognitive impairment related to prenatal exposure to ethanol is warranted.
Barr
Alasdair M
AM
Center for Complex Disorders, Department of Psychiatry, University of British Columbia, Vancouver General Hospital Research Pavilion, Vancouver, Canada. albarr@interchange.ubc.ca
Hofmann
Candace E
CE
Phillips
Anthony G
AG
Weinberg
Joanne
J
Honer
William G
WG
D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000378:metabolism; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D000431:Ethanol / Q000009:adverse effects*; D005260:Female; D063647:Fetal Alcohol Spectrum Disorders / Q000378:metabolism / Q000503:physiopathology; D006624:Hippocampus / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008297:Male; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000378:metabolism / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D017397:Prefrontal Cortex / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D017729:Presynaptic Terminals / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D009435:Synaptic Transmission / Q000502:physiology; D016708:Synaptophysin / Q000032:analysis / Q000378:metabolism
D033942:Adaptor Proteins, Vesicular Transport; D009419:Nerve Tissue Proteins; D016708:Synaptophysin; C095992:complexin I; C095993:complexin II; D000431:Ethanol