Persistent Deficits in Heart Rate Response Habituation Following Neonatal Binge Ethanol Exposure
Background: We have previously shown that the rate of habituation of the heart rate orienting response to a novel odor in rats is negatively affected by neonatal ethanol exposure. Thus far, however, only young rats (16 days of age) have been tested. Given the persistence of attention and memory pro...
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Published in | Alcoholism, clinical and experimental research Vol. 33; no. 9; pp. 1596 - 1604 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK
Blackwell Publishing Ltd
01.09.2009
Wiley |
Subjects | |
Online Access | Get full text |
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Summary: | Background: We have previously shown that the rate of habituation of the heart rate orienting response to a novel odor in rats is negatively affected by neonatal ethanol exposure. Thus far, however, only young rats (16 days of age) have been tested. Given the persistence of attention and memory problems evident in humans exposed to ethanol in utero, the purpose of this experiment was to examine the longer‐term consequences of ethanol exposure on response habituation.
Methods: Ethanol (5.25 g/kg/d) was administered intragastrically to male and female Sprague‐Dawley rats on postnatal days (PD) 4 to 9, and controls were given sham intubations. Animals were tested for heart rate orienting and response habituation to a novel olfactory stimulus (amyl acetate) on PD 16, 23, or 30.
Results: Animals tested on PD 16 or 23 showed normal heart rate deceleration to the novel odor, a measure of the orienting response. However, ethanol‐treated subjects showed impaired response habituation compared with sham controls. While controls exhibited complete habituation within 4 to 5 trials, ethanol‐treated animals continued to respond throughout the testing session, with little decrement in heart rate response magnitude across 10 stimulus presentations. A different pattern of responding was observed in animals tested during adolescence (PD 30). Control animals failed to show the typical heart rate decrease indicative of orienting, and instead showed a tendency toward tachycardia. In contrast, ethanol‐treated animals tested on PD 30 showed orienting bradycardia that persisted for several trials.
Conclusions: These data suggest that there are relatively long‐term consequences of neonatal ethanol exposure on nonassociative memory. This impairment in habituation may be relevant to the distractibility and poor focused attention that is pervasive among humans diagnosed with fetal alcohol spectrum disorders. |
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Bibliography: | ArticleID:ACER991 istex:8530FEB808CE12F558E99D73C30940AA00173770 ark:/67375/WNG-CDNSXXVS-R Present address: Department of Psychology, Virginia Polytechnic Institute and State University, Mail Code 0436, Blacksburg, Virginia. ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0145-6008 1530-0277 |
DOI: | 10.1111/j.1530-0277.2009.00991.x |