Sex- and estrous-related response patterns for alcohol depend critically on the level of compulsion-like challenge.

Alcohol use disorder is a substantial social and economic burden. During the last years, the number of women with drinking problems has been increasing, and one main concern is that they are particularly more vulnerable to negative consequences of alcohol. However, little is known about female-specific response patterns for alcohol, and potential underlying differences in brain mechanisms, including for compulsion-like alcohol drinking (when intake persists despite adverse consequences). We used lickometry to assess behavioral microstructure in adult Wistar male and female rats (n = 28-30) during alcohol-only drinking or moderate- or higher-challenge alcohol compulsion (10 or 60 mg/l quinine in alcohol, respectively). Estrous stages were determined and related to drinking levels and patterns of responding to alcohol, as was ovariectomy. Our findings showed that females (where we didn't determine estrus stage) had similar total licks in a session as males, but significantly longer licking bouts under alcohol-only and moderate-challenge, suggesting greater persistence. Further, greater intake under alcohol-only and moderate-challenge was related to faster licking in males, while female consumption was not related to licking speed. Thus, females could have increased persistence without greater vigor, unlike males. However, under higher-challenge, faster licking did predict higher intake in females, similar to males. To better understand female higher-challenge responding, we examined drinking in relation to phases of the estrous cycle. Higher-challenge had longer bouts only in late diestrus. In addition, ovariectomy led to longer bouts only under higher-challenge, suggesting that conditions with reduced hormone levels could increase female persistence for alcohol under higher-challenge. However, ovariectomy also reduced alcohol-only and moderate-challenge drinking but did not reduce bout length. Thus, intake level and response strategy could be regulated somewhat differently by ovarian hormones. Finally, moderate-challenge licking speed was less variable during early diestrus, and we previously showed more stereotyped responding specifically under moderate-challenge in males. By combining behavioral microstructure and sex- and estrus-related changes in drinking patterns, our results suggest that females have greater persistence for alcohol under lower-challenge drinking, while late diestrus and ovariectomy unmasked greater persistence under higher-challenge. Together, our novel insights could help develop more effective and personalized treatments for problematic alcohol use.

Algorithmic assessment of shoulder function using smartphone video capture and machine learning.

Tears within the stabilizing muscles of the shoulder, known as the rotator cuff (RC), are the most common cause of shoulder pain-often presenting in older patients and requiring expensive advanced imaging for diagnosis. Despite the high prevalence of RC tears within the elderly population, there is no previously published work examining shoulder kinematics using markerless motion capture in the context of shoulder injury. Here we show that a simple string pulling behavior task, where subjects pull a string using hand-over-hand motions, provides a reliable readout of shoulder mobility across animals and humans. We find that both mice and humans with RC tears exhibit decreased movement amplitude, prolonged movement time, and quantitative changes in waveform shape during string pulling task performance. In rodents, we further note the degradation of low dimensional, temporally coordinated movements after injury. Furthermore, a logistic regression model built on our biomarker ensemble succeeds in classifying human patients as having a RC tear with > 90% accuracy. Our results demonstrate how a combined framework bridging animal models, motion capture, convolutional neural networks, and algorithmic assessment of movement quality enables future research into the development of smartphone-based, at-home diagnostic tests for shoulder injury.

A Tool for Low-Cost, Quantitative Assessment of Shoulder Function Using Machine Learning.

Tears within the stabilizing muscles of the shoulder, known as the rotator cuff (RC), are the most common cause of shoulder pain-often presenting in older patients and requiring expensive, advanced imaging for diagnosis1-4. Despite the high prevalence of RC tears within the elderly population, there are no accessible and low-cost methods to assess shoulder function which can eschew the barrier of an in-person physical exam or imaging study. Here we show that a simple string pulling behavior task, where subjects pull a string using hand-over-hand motions, provides a reliable readout of shoulder health across animals and humans. We find that both mice and humans with RC tears exhibit decreased movement amplitude, prolonged movement time, and quantitative changes in waveform shape during string pulling task performance. In rodents, we further note the degradation of low dimensional, temporally coordinated movements after injury. Furthermore, a predictive model built on our biomarker ensemble succeeds in classifying human patients as having a RC tear with >90% accuracy. Our results demonstrate how a combined framework bridging task kinematics, machine learning, and algorithmic assessment of movement quality enables future development of smartphone-based, at-home diagnostic tests for shoulder injury.

Transition from predictable to variable motor cortex and striatal ensemble patterning during behavioral exploration.

Animals can capitalize on invariance in the environment by learning and automating highly consistent actions; however, they must also remain flexible and adapt to environmental changes. It remains unclear how primary motor cortex (M1) can drive precise movements, yet also support behavioral exploration when faced with consistent errors. Using a reach-to-grasp task in rats, along with simultaneous electrophysiological monitoring in M1 and dorsolateral striatum (DLS), we find that behavioral exploration to overcome consistent task errors is closely associated with tandem increases in M1 and DLS neural variability; subsequently, consistent ensemble patterning returns with convergence to a new successful strategy. We also show that compared to reliably patterned intracranial microstimulation in M1, variable stimulation patterns result in significantly greater movement variability. Our results thus indicate that motor and striatal areas can flexibly transition between two modes, reliable neural pattern generation for automatic and precise movements versus variable neural patterning for behavioral exploration.

The role of anterior insula-brainstem projections and alpha-1 noradrenergic receptors for compulsion-like and alcohol-only drinking.

Compulsion-like alcohol drinking (CLAD), where consumption continues despite negative consequences, is a major obstacle to treating alcohol use disorder. The locus coeruleus area in the brainstem and norepinephrine receptor (NER) signaling in forebrain cortical regions have been implicated in adaptive responding under stress, which is conceptually similar to compulsion-like responding (adaptive responding despite the presence of stress or conflict). Thus, we examined whether anterior insula (aINS)-to-brainstem connections and alpha-1 NERs regulated compulsion-like intake and alcohol-only drinking (AOD). Halorhodopsin inhibition of aINS-brainstem significantly reduced CLAD, with no effect on alcohol-only or saccharin intake, suggesting a specific aINS-brainstem role in aversion-resistant drinking. In contrast, prazosin inhibition of alpha-1 NERs systemically reduced both CLAD and AOD. Similar to systemic inhibition, intra-aINS alpha-1-NER antagonism reduced both CLAD and AOD. Global aINS inhibition with GABAR agonists also strongly reduced both CLAD and AOD, without impacting saccharin intake or locomotion, while aINS inhibition of calcium-permeable AMPARs (with NASPM) reduced CLAD without impacting AOD. Finally, prazosin inhibition of CLAD and AOD was not correlated with each other, systemically or within aINS, suggesting the possibility that different aINS pathways regulate CLAD versus AOD, which will require further study to definitively address. Together, our results provide important new information showing that some aINS pathways (aINS-brainstem and NASPM-sensitive) specifically regulate compulsion-like alcohol consumption, while aINS more generally may contain parallel pathways promoting CLAD versus AOD. These findings also support the importance of the adaptive stress response system for multiple forms of alcohol drinking.

Pediatric and Adolescent Shoulder Instability: Does Insurance Status Predict Delays in Care, Outcomes, and Complication Rate?

BACKGROUND: Recurrent shoulder instability results from overuse injuries that are often associated with athletic activity. Timely diagnosis and treatment are necessary to prevent further dislocations and secondary joint damage. In pediatric and adolescent patients, insurance status is a potential barrier to accessing timely care that has not yet been explored. PURPOSE: To examine the effect of insurance status on access to clinical consultation, surgical intervention, and surgical outcome of pediatric and adolescent patients with recurrent shoulder instability. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: We conducted a retrospective review of pediatric and adolescent patients who were treated at a single tertiary children's hospital for recurrent shoulder instability between 2011 and 2017. Patients were sorted into private and public insurance cohorts. Dates of injury, consultation, and surgery were recorded. Number of previous dislocations, magnetic resonance imaging (MRI) results, surgical findings, and postoperative complications were also noted. Delays in care were compared between the cohorts. The presence of isolated anterior versus complex labral pathology as well as bony involvement at the time of surgery was recorded. The incidences of labral pathology and secondary bony injury were then compared between the 2 cohorts. Postoperative notes were reviewed to compare rates of repeat dislocation and repeat surgery. RESULTS: A total of 37 patients had public insurance, while 18 patients had private insurance. Privately insured patients were evaluated nearly 5 times faster than were publicly insured patients (P < .001), and they obtained MRI scans over 4 times faster than did publicly insured patients (P < .001). Publicly insured patients were twice as likely to have secondary bony injuries (P = .016). Postoperatively, a significantly greater number (24.3%) of publicly insured patients experienced redislocation versus the complete absence of redislocation in the privately insured patients (P = .022). CONCLUSION: Public insurance status affected access to care and was correlated with the development of secondary bony injury and a higher rate of postoperative dislocations. Clinicians should practice with increased awareness of how public insurance status can significantly affect patient outcomes by delaying access to care-particularly if delays lead to increased patient morbidity and health care costs.

Behavioral indicators of succeeding and failing under higher-challenge compulsion-like alcohol drinking in rat.

Intake despite negative consequences (compulsivity) contributes strongly to the harm of alcohol use disorder, making the underlying psychological and circuit mechanisms of great importance. To gain insight into possible underlying action strategies, we compared rat licking microstructure across compulsion-like and non-compulsive conditions. We previously showed that drinking under a moderate-challenge, quinine-alcohol model (Alc-ModQ) shows less variable responding in many measures, suggesting a more automatic strategy to overcome challenge. Here, we reanalyzed our original data, newly focusing on the behavioral profile of higher-challenge intake (100 mg/L quinine in alcohol, Alc-HighQ). Alc-HighQ greatly dropped consumption, yet retained aspects of greater automaticity and drive seen with Alc-ModQ, including earlier bout initiation and measures suggesting more stereotyped tongue control. In contrast, Alc-HighQ disordered bout generation and timing. Importantly, only fast-starting bouts persisted under Alc-HighQ, and while there were many fewer longer Alc-HighQ bouts, they still contributed >50 % of consumption. Also, longer bouts under Alc-HighQ had an early, several-second period with greater chance of stopping, but afterwards showed similar persistence and recovery from slow licking as other drinking conditions. Together, our findings elucidate novel behavioral indicators of successful and unsuccessful epochs of Alc-HighQ, compulsion-like intake. We also relate findings to congruent human and animal work implicating anterior insula and medial prefrontal cortices as critical for compulsion-like alcohol responding, and where ventral frontal cortex has been more associated with overall action plan and tongue control (retained under Alc-HighQ), with medial cortex more related to proximal action timing (disrupted under Alc-HighQ except after faster bout initiation).

A novel NMDA receptor-based intervention to suppress compulsion-like alcohol drinking.

Compulsive drives for alcohol, where intake persists despite adverse consequences, are substantial obstacles to treating Alcohol Use Disorder (AUD). However, there are limited treatment options and thus considerable interest in identifying new, potent and safe pharmacotherapies. We found that non-canonical N-methyl-d-aspartate receptors (NMDARs), active at hyperpolarized potentials, drive compulsion-like alcohol drinking in rats without affecting regular, alcohol-only intake. Congruent human studies suggest that NMDAR inhibition reduces alcohol drinking in treatment-seekers but not non-treatment-seekers and suppresses craving. These cross-species studies of consumption under conflict indicate that inhibiting non-canonical NMDARs could be of clinical value for AUD. d-serine activates NMDARs overall, but actually inhibits non-canonical NMDARs. Also, d-serine has been widely tested in humans as a moderate NMDAR modulator, but some nephrotoxicity concerns remain, and thus any strategy that reduces d-serine exposure could be of broad utility. Here, co-administration of sodium benzoate (NaBenz), which reduces d-serine breakdown, allowed subthreshold d-serine levels to suppress compulsion-like alcohol drinking without altering normal alcohol-only consumption, providing a novel intervention for AUD and underscoring the importance of non-canonical NMDARs for compulsion-like intake. Low NaBenz doses alone had no average effect on intake. NaBenz/d-serine reduced compulsion-like intake in nearly all animals, while higher d-serine alone decreased compulsion-like intake with less of an effect in lower-drinking subjects. Thus, combining subthreshold NaBenz and d-serine suppressed compulsion-like intake, helping both to alleviate some d-serine concerns, and, importantly, to reduce consequence-resistant consumption across nearly all individuals. Therefore, NaBenz/d-serine likely represents an FDA-approved and immediately-accessible pharmacotherapy to help counteract compulsion-like drives and treat AUD.

Effect of levodopa on electroencephalographic biomarkers of the parkinsonian state.

The objective of this study was to evaluate proposed electroencephalographic (EEG) biomarkers of Parkinson's disease (PD) and test their correlation with motor impairment in a new, well-characterized cohort of PD patients and controls. Sixty-four-channel EEG was recorded from 14 patients with rigid-akinetic PD with minimal tremor and from 14 age-matched healthy controls at rest and during voluntary movement. Patients were tested off and on medication during a single session. Recordings were analyzed for phase-amplitude coupling over sensorimotor cortex and for pairwise coherence from all electrode pairs in the recording montage (distributed coherence). Phase-amplitude coupling and distributed coherence were found to be elevated Off compared with On levodopa, and their reduction was correlated with motor improvement. In the Off medication state, phase-amplitude coupling was greater in sensorimotor contacts contralateral to the most affected body part and reduced by voluntary movement. We conclude that phase-amplitude coupling and distributed coherence are cortical biomarkers of the parkinsonian state that are detectable noninvasively and may be useful as objective aids for management of dopaminergic therapy. Several analytic methods may be used for noninvasive measurement of abnormal brain synchronization in PD. Calculation of phase-amplitude coupling requires only a single electrode over motor cortex. NEW & NOTEWORTHY Several EEG biomarkers of the parkinsonian state have been proposed that are related to abnormal cortical synchronization. We report several new findings in this study: correlations of EEG markers of synchronization with specific motor signs of Parkinson's disease (PD), and demonstration that one of the EEG markers, phase-amplitude coupling, is more elevated over the more clinically affected brain hemisphere. These findings underscore the potential utility of scalp EEG for objective, noninvasive monitoring of medication state in PD.

Nucleus Accumbens Shell Orexin-1 Receptors Are Critical Mediators of Binge Intake in Excessive-Drinking Individuals.

Excessive, binge alcohol drinking is a potent and pernicious obstacle to treating alcohol use disorder (AUD), and heavy-drinking humans are responsible for much of the substantial costs and harms of AUD. Thus, identifying key mechanisms that drive intake in higher-drinking individuals may provide important, translationally useful therapeutic interventions. Orexin-1-receptors (Ox1Rs) promote states of high motivation, and studies with systemic Ox1R inhibition suggest a particular role in individuals with higher intake levels. However, little has been known about circuits where Ox1Rs promote pathological intake, especially excessive alcohol consumption. We previously discovered that binge alcohol drinking requires Ox1Rs in medial nucleus accumbens shell (Shell), using two-bottle-choice Drinking-in-the-Dark (2bc-DID) in adult, male C57BL/6 mice. Here, we show that Shell Ox1Rs promoted intake during intermittent-access alcohol drinking as well as 2bc-DID, and that Shell inhibition with muscimol/baclofen also suppressed 2bc-DID intake. Importantly, with this large data set, we were able to demonstrate that Shell Ox1Rs and overall activity were particularly important for driving alcohol consumption in higher-drinking individuals, with little overall impact in moderate drinkers. Shell inhibition results were compared with control data combined from drug treatments that did not reduce intake, including NMDAR or PKC inhibition in Shell, Ox1R inhibition in accumbens core, and systemic inhibition of dopamine-1 receptors; these were used to understand whether more specific Shell Ox1R contributions in higher drinkers might simply result from intrinsic variability in mouse drinking. Ineffectiveness of Shell inhibition in moderate-drinkers was not due to a floor effect, since systemic baclofen reduced alcohol drinking regardless of basal intake levels, without altering concurrent water intake or saccharin consumption. Finally, alcohol intake in the first exposure predicted consumption levels weeks later, suggesting that intake level may be a stable trait in each individual. Together, our studies indicate that Shell Ox1Rs are critical mediators of binge alcohol intake in higher-drinking individuals, with little net contribution to alcohol drinking in more moderate bingers, and that targeting Ox1Rs may substantially reduce AUD-related harms.

Drinking despite adversity: behavioral evidence for a head down and push strategy of conflict-resistant alcohol drinking in rats.

Compulsive alcohol drinking, where intake persists regardless of adverse consequences, plays a major role in the substantial costs of alcohol use disorder. However, the processes that promote aversion-resistant drinking remain poorly understood. Compulsion-like responding has been considered automatic and reflexive and also to involve higher motivation, since drinking persists despite adversity. Thus, we used lickometry, where microstructural behavioral changes can reflect altered motivation, to test whether conflict-resistant intake [quinine-alcohol (QuiA)] reflected greater automaticity or motivation relative to alcohol-only drinking (Alc). Front-loading during QuiA and Alc suggested incentive to drink in both. However, the relationship between total licking and intake was less variable during QuiA, as was lick volume, without changes in average responding. QuiA bout organization was also less variable, with fewer licks outside of bouts (stray licks) and fewer gaps within bouts. Interestingly, QuiA avoidance of stray licking continued into short bouts, with fewer short and more medium-length bouts, which was striking given their minor impact on intake. Instead, more effort at bout onset could allow short bouts to persist longer. Indeed, while QuiA licking was overall faster, QuiA bouts were especially fast at bout initiation. However, few QuiA changes individually predicted greater intake, perhaps suggesting an overarching strategy during aversion-resistant responding. Thus, our results indicate that aversion-resistant intake exhibited less variability, where increased automaticity could decrease need for awareness, and stronger bout initiation, which might prolong responding despite adversity. This may reflect a collective strategy, which we call Head Down and Push responding that facilitates conflict-resistant, compulsion-like intake.

Limited Excessive Voluntary Alcohol Drinking Leads to Liver Dysfunction in Mice.

BACKGROUND: Liver damage is a serious and sometimes fatal consequence of long-term alcohol intake, which progresses from early-stage fatty liver (steatosis) to later-stage steatohepatitis with inflammation and fibrosis/necrosis. However, very little is known about earlier stages of liver disruption that may occur in problem drinkers, those who drink excessively but are not dependent on alcohol. METHODS: We examined how repeated binge-like alcohol drinking in C57BL/6 mice altered liver function, as compared with a single binge-intake session and with repeated moderate alcohol consumption. We measured a number of markers associated with early- and later-stage liver disruption, including liver steatosis, measures of liver cytochrome P4502E1 (CYP2E1) and alcohol dehydrogenase (ADH), alcohol metabolism, expression of cytokine mRNA, accumulation of 4-hydroxynonenal (4-HNE) as an indicator of oxidative stress, and alanine transaminase/aspartate transaminase as a measure of hepatocyte injury. RESULTS: Importantly, repeated binge-like alcohol drinking increased triglyceride levels in the liver and plasma, and increased lipid droplets in the liver, indicators of steatosis. In contrast, a single binge-intake session or repeated moderate alcohol consumption did not alter triglyceride levels. In addition, alcohol exposure can increase rates of alcohol metabolism through CYP2E1 and ADH, which can potentially increase oxidative stress and liver dysfunction. Intermittent, excessive alcohol intake increased liver CYP2E1 mRNA, protein, and activity, as well as ADH mRNA and activity. Furthermore, repeated, binge-like drinking, but not a single binge or moderate drinking, increased alcohol metabolism. Finally, repeated, excessive intake transiently elevated mRNA for the proinflammatory cytokine IL-1B and 4-HNE levels, but did not alter markers of later-stage liver hepatocyte injury. CONCLUSIONS: Together, we provide data suggesting that even relatively limited binge-like alcohol drinking can lead to disruptions in liver function, which might facilitate the transition to more severe forms of liver damage.