Drinking alcohol during pregnancy leads to fetal alcohol spectrum disorder (FASD). One of the most prominent behavioral symptoms of FASD is attention deficit/hyperactivity disorder (ADHD). Numerous clinical and animal studies have shown a link between ADHD and abnormal functions of the mesolimbic/cortical dopaminergic (DA) system, which originates from DA neurons in the ventral tegmental area (VTA). Attention problems and abnormal DA function are also present in prenatal ethanol exposed rats, indicating the these rats can be used as an animal model to study how abnormal DA functions could lead to ADHD symptoms in individuals with FASD. In the past few years, we have found that prenatal ethanol exposure produces a persistent reduction in the number of VTA DA neurons expressing spontaneous electrical activity (DA neuron population activity). This effect is not due to permanent cell loss and can be normalized by DA agonists, including psychostimulants that are effective in treating ADHD. The effect of DA agonists also suggests that reduced VTA DA neuron population activity in prenatal ethanol exposed animals is caused by increased number of quiescent VTA DA neurons in a state of depolarization inactivation. Namely, these neurons cannot generate action potentials due to excessive excitation. Our hypothesis that reduced VTA DA neuron population activity is a result of depolarization inactivation, also predicts that the overall function of the mesolimbic/cortical DA system is altered in such a way that responses of VTA DA neurons to input signals as well as impulse-dependent DA release in terminal regions will be qualitatively different from that in controls. In the proposed studies, we will test the above hypotheses.
Under Aim 1, we will directly test the hypothesis that prenatal ethanol exposure-induced reduction in VTA DA neuron population activity is due to depolarization inactivation using the in vivo intracellular recording technique.
Under Aim 2, we will investigate the cellular mechanism that leads to reduced VTA DA neuron population activity in prenatal ethanol exposed animals.
Under Aim 3, we will investigate if there is a qualitative change in the responses of VTA DA neurons to input signals and DA release in prenatal ethanol exposed animals. The results from the proposed studies will allow us to understand how prenatal ethanol exposure alters the function of the mesolimbic/cortical DA system, which plays an important role in many behavioral functions such as attention. The information obtained from the proposed studies may help us to elucidate the etiology and treatment options of ADHD symptoms observed in many individuals with FASD. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Research Project (R01)
Project #
2R01AA012435-07A2
Application #
7258734
Study Section
Neurotoxicology and Alcohol Study Section (NAL)
Program Officer
Twombly, Dennis
Project Start
1999-04-01
Project End
2009-03-31
Budget Start
2007-04-15
Budget End
2008-03-31
Support Year
7
Fiscal Year
2007
Total Cost
$320,963
Indirect Cost
Name
State University of New York at Buffalo
Department
Type
Organized Research Units
DUNS #
038633251
City
Buffalo
State
NY
Country
United States
Zip Code
14260
Wang, Ruixiang; Hausknecht, Kathryn A; Shen, Ying-Ling et al. (2018) Environmental enrichment reverses increased addiction risk caused by prenatal ethanol exposure. Drug Alcohol Depend 191:343-347
Wang, Ruixiang; Hausknecht, Kathryn A; Haj-Dahmane, Samir et al. (2018) Decreased environmental complexity during development impairs habituation of reinforcer effectiveness of sensory stimuli. Behav Brain Res 337:53-60
Hausknecht, Kathryn; Haj-Dahmane, Samir; Shen, Ying-Ling et al. (2015) Excitatory synaptic function and plasticity is persistently altered in ventral tegmental area dopamine neurons after prenatal ethanol exposure. Neuropsychopharmacology 40:893-905
Hausknecht, Kathryn; Haj-Dahmane, Samir; Shen, Roh-Yu (2013) Prenatal stress exposure increases the excitation of dopamine neurons in the ventral tegmental area and alters their reponses to psychostimulants. Neuropsychopharmacology 38:293-301
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Haj-Dahmane, Samir; Shen, Roh-Yu (2011) Modulation of the serotonin system by endocannabinoid signaling. Neuropharmacology 61:414-20
Haj-Dahmane, Samir; Shen, Roh-Yu (2010) Regulation of plasticity of glutamate synapses by endocannabinoids and the cyclic-AMP/protein kinase A pathway in midbrain dopamine neurons. J Physiol 588:2589-604
Haj-Dahmane, Samir; Shen, Roh-Yu (2009) Endocannabinoids suppress excitatory synaptic transmission to dorsal raphe serotonin neurons through the activation of presynaptic CB1 receptors. J Pharmacol Exp Ther 331:186-96
Muschamp, John W; Dominguez, Juan M; Sato, Satoru M et al. (2007) A role for hypocretin (orexin) in male sexual behavior. J Neurosci 27:2837-45
Shen, Roh-Yu; Choong, Kar-Chan; Thompson, Alexis C (2007) Long-term reduction in ventral tegmental area dopamine neuron population activity following repeated stimulant or ethanol treatment. Biol Psychiatry 61:93-100

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