Associations of adverse childhood experiences with stress physiology and insulin resistance in adolescents at risk for adult obesity.

Adverse childhood experiences (ACEs) heighten the risk for adult obesity and cardiometabolic disease, but physiological factors underlying this connection are not well understood. We determined if ACEs were associated with physiological stress response and insulin resistance in adolescents at risk for adult obesity. Participants were 90 adolescents 12.0-17.5 years (50% female, 30% Hispanic/Latinx), at risk for adult obesity by virtue of above-average body mass index (BMI; kg/m2 ≥ 70th percentile) or parental obesity (BMI ≥ 30 kg/m2 ). ACEs were determined as presence (vs. absence) based upon the Schedule for Affective Disorders and Schizophrenia for School-Aged Children. Physiological stress response was measured as heart rate/blood pressure response to the Trier Social Stress Test. Homeostatic model assessment of insulin resistance was determined from fasting glucose/insulin. Sixty-one percent of adolescents reported positive ACE history. The presence of ACEs predicted greater heart rate (p < .001) and diastolic blood pressure (p = .02) response to stress, controlling for age, sex, race/ethnicity, puberty, and BMI standard score. Systolic blood pressure and insulin resistance did not differ by ACE history (p-values > .08). Findings suggest heightened sympathetic stress response in adolescence could be explanatory in how ACEs increase the risk for later cardiometabolic disease. Future studies should characterize ACEs in relationship to day-to-day variations in adolescents' stress physiology and glucose homeostasis.

Chronic chemogenetic manipulation of ventral pallidum targeted neurons in male rats fed an obesogenic diet.

Current treatments for obesity do not reliably reduce body weight over time. New interventional strategies, including chemogenetics, carry promise based on preclinical animal studies. Here, we focused on the ventral pallidum (VP) due to its clearly established role in eating behavior. Chronic inhibitory or excitatory chemogenetic activation was used to modulate the activity of VP-targeted neurons in rats on an obesogenic diet. Based on studies using acute VP manipulations, we hypothesized that VP inhibition would decrease weight gain, while VP stimulation would increase weight. Instead, both manipulations caused weight gain over time, and in a manner not clearly linked to consumption levels. We theorize that the complex reciprocal feedback between ventral striatal structures and metabolic centers likely underpin our unexpected findings. Regardless, this study suggests that the result of strategies to prevent obesity with chronic neuromodulation could be difficult to predict from prior preclinical studies that have used acute interventions.

Corticostriatal Oscillations Predict High vs. Low Drinkers in a Rat Model of Limited Access Alcohol Consumption.

Individuals differ in their vulnerability to develop alcohol dependence, which is determined by innate and environmental factors. The corticostriatal circuit is heavily involved in the development of alcohol dependence and may contain neural information regarding vulnerability to drink excessively. In the current experiment, we hypothesized that we could characterize high and low alcohol-drinking rats (HD and LD, respectively) based on corticostriatal oscillations and that these subgroups would differentially respond to corticostriatal brain stimulation. Male Sprague-Dawley rats (n = 13) were trained to drink 10% alcohol in a limited access paradigm. In separate sessions, local field potentials (LFPs) were recorded from the nucleus accumbens shell (NAcSh) and medial prefrontal cortex (mPFC). Based on training alcohol consumption levels, we classified rats using a median split as HD or LD. Then, using machine-learning, we built predictive models to classify rats as HD or LD by corticostriatal LFPs and compared the model performance from real data to the performance of models built on data permutations. Additionally, we explored the impact of NAcSh or mPFC stimulation on alcohol consumption in HD vs. LD. Corticostriatal LFPs were able to predict HD vs. LD group classification with greater accuracy than expected by chance (>80% accuracy). Moreover, NAcSh stimulation significantly reduced alcohol consumption in HD, but not LD (p < 0.05), while mPFC stimulation did not alter drinking behavior in either HD or LD (p > 0.05). These data collectively show that the corticostriatal circuit is differentially involved in regulating alcohol intake in HD vs. LD rats, and suggests that corticostriatal activity may have the potential to predict a vulnerability to develop alcohol dependence in a clinical population.