TY - JOUR
T1 - Targeted deletion of the mouse α2 nicotinic acetylcholine receptor subunit gene (Chrna2) potentiates nicotine-modulated behaviors
AU - Lotfipour, Shahrdad
AU - Byun, Janet S.
AU - Leach, Prescott
AU - Fowler, Christie D.
AU - Murphy, Niall P.
AU - Kenny, Paul J.
AU - Gould, Thomas J.
AU - Boulter, Jim
PY - 2013
Y1 - 2013
N2 - Baseline and nicotine-modulated behaviors were assessed in mice harboring a null mutant allele of the nicotinic acetylcholine receptor (nAChR) subunit gene α2 (Chrna2). Homozygous Chrna2-/- mice are viable, show expected sex and Mendelian genotype ratios, and exhibit no gross neuroanatomical abnormalities. A broad range of behavioral tests designed to assess genotype-dependent effects on anxiety (elevated plus maze and light/dark box), motor coordination (narrow bean traverse and gait), and locomotor activity revealed no significant differences between mutant mice and age-matched wild-type littermates. Furthermore, a panel of tests measuring traits, such as body position, spontaneous activity, respiration, tremors, body tone, and startle response, revealed normal responses for Chrna2-null mutant mice. However, Chrna2-/- mice do exhibit a mild motor or coordination phenotype (a decreased latency to fall during the accelerating rotarod test) and possess an increased sensitivity to nicotine-induced analgesia in the hotplate assay. Relative to wild-type, Chrna2-/- mice show potentiated nicotine self-administration and withdrawal behaviors and exhibit a sex-dependent enhancement of nicotine-facilitated cued, but not trace or contextual, fear conditioning. Overall, our results suggest that loss of the mouse nAChR α2 subunit has very limited effects on baseline behavior but does lead to the potentiation of several nicotine-modulated behaviors.
AB - Baseline and nicotine-modulated behaviors were assessed in mice harboring a null mutant allele of the nicotinic acetylcholine receptor (nAChR) subunit gene α2 (Chrna2). Homozygous Chrna2-/- mice are viable, show expected sex and Mendelian genotype ratios, and exhibit no gross neuroanatomical abnormalities. A broad range of behavioral tests designed to assess genotype-dependent effects on anxiety (elevated plus maze and light/dark box), motor coordination (narrow bean traverse and gait), and locomotor activity revealed no significant differences between mutant mice and age-matched wild-type littermates. Furthermore, a panel of tests measuring traits, such as body position, spontaneous activity, respiration, tremors, body tone, and startle response, revealed normal responses for Chrna2-null mutant mice. However, Chrna2-/- mice do exhibit a mild motor or coordination phenotype (a decreased latency to fall during the accelerating rotarod test) and possess an increased sensitivity to nicotine-induced analgesia in the hotplate assay. Relative to wild-type, Chrna2-/- mice show potentiated nicotine self-administration and withdrawal behaviors and exhibit a sex-dependent enhancement of nicotine-facilitated cued, but not trace or contextual, fear conditioning. Overall, our results suggest that loss of the mouse nAChR α2 subunit has very limited effects on baseline behavior but does lead to the potentiation of several nicotine-modulated behaviors.
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U2 - 10.1523/JNEUROSCI.4731-12.2013
DO - 10.1523/JNEUROSCI.4731-12.2013
M3 - Article
C2 - 23637165
AN - SCOPUS:84877109504
SN - 0270-6474
VL - 33
SP - 7728
EP - 7741
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 18
ER -