Elucidation of pharmacologically manipulated responding in the delay discounting task in high alcohol preferring mice

Impulsive behavior is the hallmark of many psychopathologies. Uncovering the neurobiological mechanisms driving impulsivity is paramount in the development of through the delay discounting (DD) task in both human and animal models. The present study is an examination of the predictive validity of the two primary types of DD procedures in animals, the Adjusting Amounts (AA) and within session Increasing Delays (ID) tasks. Methods:Subjects were administered either1.25 mg/kg d-amphetamine (AMP), 1.5 g/kg ethanol (EtOH) or saline and tested in either the AA or ID method for 15 days to evaluate drug effects on impulsive behavior. Results: Stimulant administration resulted in a reduction of impulsivity in the AA group, but had no effect in the ID group. There was no effect on impulsivity of EtOH administration in AA or ID groups. Conclusion: Given the ability of stimulant administration to reduce impulsivity in clinical studies, the AA version of DD provides the best predictive validity for the animal mode

Integrating Preclinical and Clinical Models of Negative Urgency

Overwhelming evidence suggests that negative urgency is robustly associated with rash, ill-advised behavior, and this trait may hamper attempts to treat patients with substance use disorder. Research applying negative urgency to clinical treatment settings has been limited, in part, due to the absence of an objective, behavioral, and translational model of negative urgency. We suggest that development of such a model will allow for determination of prime neurological and physiological treatment targets, the testing of treatment effectiveness in the preclinical and the clinical laboratory, and, ultimately, improvement in negative-urgency-related treatment response and effectiveness. In the current paper, we review the literature on measurement of negative urgency and discuss limitations of current attempts to assess this trait in human models. Then, we review the limited research on animal models of negative urgency and make suggestions for some promising models that could lead to a translational measurement model. Finally, we discuss the importance of applying objective, behavioral, and translational models of negative urgency, especially those that are easily administered in both animals and humans, to treatment development and testing and make suggestions on necessary future work in this field. Given that negative urgency is a transdiagnostic risk factor that impedes treatment success, the impact of this work could be large in reducing client suffering and societal costs

Effects of the Selective PDE4B Inhibitor TDP-003 on Ethanol Consumption

poster abstractAlcoholism is a disease that affects about 18 million Americans. Inhibition of drinking behavior can help develop better therapeutic and medical treatments to these people. Phosphodiesterase-4 (PDE4) is an enzyme that helps breakdown cAMP, which in turn decrease alcohol consumption. cHAP mice are known to have a unique strong preference to ethanol. However, it is not yet known whether or not this relatively new strain of mice are affected by known agonists and antagonist neurotransmitters that reduce ethanol consumption in cousin strains. cHAP mice were used in this particular study due to their unique genetic make-up of having an above average preference to ethanol. The mice were trained for ethanol preference for two weeks. Once the cHAPs obtained stable ethanol consumption, the drug TDP-003, which contains the PDE4B subtype inhibitor, was administered in the morning with interval ethanol and water consumption readings every two hours from the time of injection. TDP-003 was given in three separate doses; 0.03ml, 0.1ml, and a 0.3ml mg/k along with a vehicle dose, which served as a control. Once data was collected and analyzed, it was found that there was not a significant effect in the amount of ethanol the cHAPs were consuming with the drug. In order to ensure that this result was not due to an experimental methods design error, the cHAPs were ran for another week on stable ethanol consumption and then injected with rolipram to see if a positive effect occurred. Rolipram is also a PDE4 inhibitor; predominantly affecting the PDE4B subtype. cHAPS were given three separate doses of rolipram, a 0.1ml, 0.25ml, and a 0.5ml mg/k dose, along with a vehicle dose. Once again, there were no significant differences in the amount of ethanol consumption that was consumed; thus implying that TDP-003 did not work

Aberrations of anterior insular cortex functional connectivity in nontreatment-seeking alcoholics

An emergent literature suggests that resting state functional magnetic resonance imaging (rsfMRI) functional connectivity (FC) patterns are aberrant in alcohol use disorder (AUD) populations. The salience network (SAL) is an established set of brain regions prominent in salience attribution and valuation, and includes the anterior insular cortex (AIC). The SAL is thought to play a role in AUD through directing increased attention to interoceptive cues of intoxication. There is very little information on the salience network (SAL) in AUD, and, in particular, there are no data on SAL FC in currently drinking, nontreatment seeking individuals with AUD (NTS). rsfMRI data from 16 NTS and 21 social drinkers (SD) were compared using FC correlation maps from ten seed regions of interest in the bilateral AIC. As anticipated, SD subjects demonstrated greater insular FC with frontal and parietal regions. We also found that, compared to SD, NTS had higher insular FC with hippocampal and medial orbitofrontal regions. The apparent overactivity in brain networks involved in salience, learning, and behavioral control in NTS suggests possible mechanisms in the development and maintenance of AUD

Chronic free-choice drinking in crossed HAP (cHAP) mice leads to sustained blood ethanol levels and metabolic tolerance without evidence of liver damage

Background Crossed High Alcohol Preferring (cHAP) mice were selectively bred from a cross of the HAP1xHAP2 replicate lines, and demonstrate blood ethanol concentrations (BECs) during free-choice drinking that are reminiscent of those observed in alcohol-dependent humans. Therefore, this line may provide an unprecedented opportunity to learn about the consequences of excessive voluntary ethanol consumption, including metabolic tolerance and liver pathology. Cytochrome p450 2E1 (CYP 2E1) induction plays a prominent role in driving both metabolic tolerance and ethanol-induced liver injury. In this report, we sought to characterize cHAP drinking by assessing whether pharmacologically relevant BEC levels are sustained throughout the active portion of the light-dark cycle. Given that cHAP intakes and BECs are similar to those observed in mice given an ethanol liquid diet, we assessed whether free-choice exposure results in metabolic tolerance, hepatic enzyme induction, and hepatic steatosis. Methods In Experiment 1, blood samples were taken across the dark portion of a 12:12 light-dark cycle to examine the pattern of ethanol accumulation in these mice. In Experiments 1 and 2, mice were injected with ethanol following 3–4 weeks of access to water or 10% ethanol and water, and blood samples were taken to assess metabolic tolerance. In Experiment 3, 24 mice had 4 weeks access to 10% ethanol and water or water alone, followed by necropsy and hepatological assessment. Results In experiment 1, cHAP mice mean BEC values exceeded 80 mg/dl at all sampling points, and approached 200 mg/dl during the middle of the dark cycle. In experiments 1 and 2, ethanol-exposed mice metabolized ethanol faster than ethanol-naïve mice, demonstrating metabolic tolerance (p < .05). In experiment 3, ethanol-drinking mice showed greater expression of hepatic CYP 2E1 than water controls, consistent with the development of metabolic tolerance (p < .05). Ethanol access altered neither hepatic histology nor levels of ADH and ALDH. Conclusions These results demonstrate that excessive intake by cHAP mice results in sustained BECs throughout the active period, leading to the development of metabolic tolerance and evidence of CYP 2E1 induction. Together these results provide additional support for the cHAP mice as a highly translational rodent model of alcoholism

Differences in White Matter Microstructure and Connectivity in Nontreatment‐Seeking Individuals with Alcohol Use Disorder

Background Diffusion‐weighted imaging (DWI) has been widely used to investigate the integrity of white matter (WM; indexed by fractional anisotropy [FA]) in alcohol dependence and cigarette smoking. These disorders are highly comorbid, yet cigarette use has often not been adequately controlled in neuroimaging studies of alcohol‐dependent populations. In addition, information on WM deficits in currently drinking, nontreatment‐seeking (NTS) individuals with alcohol dependence is limited. Therefore, the aim of this work was to investigate WM microstructural integrity in alcohol use disorder by comparing matched samples of cigarette smoking NTS and social drinkers (SD). Methods Thirty‐eight smoking NTS and 19 smoking SD subjects underwent DWI as well as structural magnetic resonance imaging. After an in‐house preprocessing of the DWI data, FA images were analyzed with tract‐based spatial statistics (TBSS). FA obtained from the TBSS skeleton was tested for correlation with recent alcohol consumption. Results Smoking NTS had lower FA relative to smoking SD, predominantly in the left hemisphere (p < 0.05, family‐wise error rate corrected across FA skeleton). Across the full sample, FA and number of drinks per week were negatively related (ρ = −0.348, p = 0.008). Qualitative analyses of the structural connections through compromised WM as identified by TBSS showed differential connectivity of gray matter in NTS compared to SD subjects of left frontal, temporal, and parietal regions. Conclusions NTS subjects had lower WM FA than SD, indicating compromised WM integrity in the NTS population. The inverse relationship of entire WM skeleton FA with self‐reported alcohol consumption supports previous evidence of a continuum of detrimental effects of alcohol consumption on WM. These results provide additional evidence that alcohol dependence is associated with reduced WM integrity in currently drinking NTS alcohol‐dependent individuals, after controlling for the key variable of cigarette smoking

Lithium effects on ethanol intake in impulsive mice

The present study sought to identify the effects of chronic lithium administration on ethanol intakes in high alcohol-preferring (HAP) mice. Lithium is a well-established treatment for bipolar disorder and has demonstrated efficacy in reducing impulsivity, an endophenotype of the disease. Impulsivity is also a prominent trait of alcoholism. HAP mice display a preference for consuming substantial amounts of ethanol and exhibit abnormally high levels of impulsivity. Previous work has determined that chronic lithium exposure in HAP mice reduces their levels of impulsivity. The present study analyzed fluctuations in established intake patterns after lithium exposure and how pre-exposure to lithium would affect ethanol intake acquisition. The results showed an increase in ethanol intake and no change in preference for ethanol over water in lithium treated mice. There was an increase in overall total fluid consumption in these mice, likely resulting from polydipsic effects. There also appeared to be a potentiated lithium toxicity effect found in those mice pre-exposed to lithium. The conclusion was that lithium therapy does not decrease ethanol consumption in HAP mice

Delay discounting and alcohol consumption correlate with dorsal anterior insula activation during choice in nontreatment-seeking heavy drinkers.

BACKGROUND: The anterior insular cortex (AIC), a prominent salience network node, integrates interoceptive information and emotional states into decision making. While AIC activation during delay discounting (DD) in alcohol use disorder (AUD) has been previously reported, the associations between AIC activation, impulsive choice, alcohol consumption, and connectivity remain unknown. We therefore tested AIC brain responses during DD in heavy drinkers and their association with DD performance, alcohol drinking, and task-based connectivity. METHODS: Twenty-nine heavy drinkers (12 females; mean (SD) age=31.5 ± 6.1 years; mean (SD)=40.8 ± 23.4 drinks/week) completed a DD task during functional MRI. Regions activated during DD decision making were tested for correlation with DD behavior and alcohol drinking. Psychophysiological interaction (PPI) models assessed the task-dependent functional connectivity (FC) of activation during choice. RESULTS: Delay discounting choice activated bilateral anterior insular cortex, anterior cingulate cortex, and left precentral gyrus. Right dorsal (d) AIC activation during choice negatively correlated withdiscounting of delayed rewards and alcohol consumption. PPI analysis revealed FC of the right dAIC to both the anterior and posterior cingulate cortices-key nodes in the midline default mode network. CONCLUSIONS: Greater dAIC involvement in intertemporal choice may confer more adaptive behavior (lower impulsivity and alcohol consumption). Moreover, salience network processes governing discounting may require midline default mode (precuneus/posterior cingulate cortex) recruitment. These findings supporta key adaptive role for right dAIC in decision making involving future rewards and risky drinking

Delay discounting and alcohol consumption correlate with dorsal anterior insula activation during choice in non‐treatment‐seeking heavy drinkers

Background The anterior insular cortex (AIC), a prominent salience network node, integrates interoceptive information and emotional states into decision-making. While AIC activation during delay discounting (DD) in alcohol use disorder (AUD) has been previously reported, the associations between AIC activation, impulsive choice, alcohol consumption, and connectivity remain unknown. We therefore tested AIC brain responses during DD in heavy drinkers and their association with DD performance, alcohol drinking, and task-based connectivity. Methods Twenty-nine heavy drinkers (12 females; 31.5±6.1 years; 40.8±23.4 drinks/week) completed a DD task during functional MRI. Regions activated during delay discounting decision-making were tested for correlations with DD behavior and alcohol drinking. Psychophysiological interaction (PPI) models assessed task-dependent functional connectivity (FC) of activation during choice. Results DD choice activated bilateral anterior insular cortex, anterior cingulate cortex, and left precentral gyrus. Right dorsal (d) AIC activation during choice negatively correlated with discounting of delayed rewards and alcohol consumption. PPI analysis revealed FC of right dAIC to both anterior and posterior cingulate cortex (PCC)—key nodes in the midline default mode network. Conclusions Greater dAIC involvement in intertemporal choice may confer more adaptive behavior (lower impulsivity and alcohol consumption). Moreover, salience network processes governing discounting may require midline default mode (precuneus/PCC) recruitment. These findings support a key adaptive role for right dAIC in decision-making involving future rewards and risky drinking

Records of mammals from northeast and south Texas

Volume: 200Start Page: 1End Page: