Using wastewater to overcome health disparities among rural residents.

The SARS-CoV-2 pandemic highlighted the need for novel tools to promote health equity. There has been a historical legacy around the location and allocation of public facilities (such as health care) focused on efficiency, which is not attainable in rural, low-density, United States areas. Differences in the spread of the disease and outcomes of infections have been observed between urban and rural populations throughout the COVID-19 pandemic. The purpose of this article was to review rural health disparities related to the SARS-CoV-2 pandemic while using evidence to support wastewater surveillance as a potentially innovative tool to address these disparities more widely. The successful implementation of wastewater surveillance in resource-limited settings in South Africa demonstrates the ability to monitor disease in underserved areas. A better surveillance model of disease detection among rural residents will overcome issues around the interactions of a disease and social determinants of health. Wastewater surveillance can be used to promote health equity, particularly in rural and resource-limited areas, and has the potential to identify future global outbreaks of endemic and pandemic viruses.

Engaging Undergraduate Students in Substance Use and Related Mental Health Disorders Research within South Dakota: A Review of the Summer Program for Undergraduate Research in Addiction (SPURA).

BACKGROUND: The Summer Program for Undergraduate Research in Addiction (SPURA) at the University of South Dakota provides research opportunities to better understand substance use and related mental health disorders. The program was initiated in 2014 from funding from the National Institute on Drug Abuse with a mission to provide high-quality mentorship and research experiences for undergraduate students, including those underrepresented in science, technology, engineering, and math. METHODS: Students from the University of South Dakota were recruited to participate in this program. Survey responses and demographic information were collected from the students. RESULTS: During the first five years, 37 students completed the program. Many of these students were underrepresented in science. Of the students that had completed their undergraduate degree at the time of the last survey, most students either continued their education in a health professional or graduate program, or were employed in a career related to mental health or substance use. CONCLUSIONS: The current report reflects upon the outcomes of the program and future directions. With continued effort, SPURA will provide critical education for future leaders and health care professionals on topics related to substance use and mental health disorders, resulting in a greater number of advocates for those afflicted by substance use.

Optogenetic inhibition of the medial prefrontal cortex reduces methamphetamine-primed reinstatement in male and female rats.

Preclinical findings suggest sex-differences exist in drug-seeking behavior following methamphetamine (METH) self-administration. The medial prefrontal cortex (mPFC), is thought to contribute to the reinstatement of drug-seeking in males. Glutamatergic neurons project from the prelimbic portion of the mPFC to various brain regions modulating activity including the nucleus accumbens; thus the prelimbic region of the mPFC is thought to contribute to drug-seeking behaviors. Although studied in males, little research has investigated the role of the mPFC in females. The purpose of this study was to investigate if the prelimbic portion of the mPFC plays a role in METH-seeking behavior in both male and female rats. Animals were allowed to self-administer METH, and underwent extinction and two reinstatement sessions. Reinstatement sessions were counterbalanced such that optogenetic inhibition targeting the prelimbic cortex of the mPFC occurred only during one reinstatement session. Results revealed an increase in METH consumption during self-administration in male and female animals. During extinction, lever-pressing behavior decreased as training progressed. Under sham conditions, female rats exhibited significantly higher drug-seeking behavior during reinstatement. However, when optogenetic inhibition was applied, both male and female animals significantly decreased drug-seeking. In both males and females, the prelimbic portion of the mPFC plays an important role in drug-seeking behavior as related to METH-seeking.

Behavioral and Serotonergic Changes in the Frontal Cortex Following Methamphetamine Self-Administration.

BACKGROUND: Methamphetamine use is associated with a variety of negative health outcomes, including psychosis. The frontal cortex serotonin receptors are thought to contribute to psychosis-like behaviors. This study investigated changes in serotonergic markers in the frontal cortex following methamphetamine self-administration and hallucinogenic drug-induced behavior. METHODS: Consistent with previously published studies, freely cycling male and female rats were allowed to self-administer methamphetamine (males: 0.12 mg/infusion; females: 0.09 mg/infusion) or saline (10 µL) for 7 days. On the day following self-administration or following 10 days of extinction training, animals were given the serotonin 2A/2C agonist, 1-(2,5-Dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (2 mg/kg, i.p.), and head twitches were analyzed. Autoradiography was also used to assess serotonin receptors and transporters in the frontal cortex following self-administration. RESULTS: Methamphetamine self-administration led to an increase in DOI-induced head-twitch behavior compared to saline only on the day following self-administration. Increases in serotonin receptors in the orbitofrontal cortex and decreases in serotonin transporters in the orbitofrontal cortex and infralimbic cortex were observed following methamphetamine self-administration as assessed by autoradiography. CONCLUSIONS: Methamphetamine self-administration was associated with serotonergic alterations in the frontal cortex, which may underlie behavioral changes related to methamphetamine-associated psychosis.

Regulation of the Dopamine and Vesicular Monoamine Transporters: Pharmacological Targets and Implications for Disease.

Dopamine (DA) plays a well recognized role in a variety of physiologic functions such as movement, cognition, mood, and reward. Consequently, many human disorders are due, in part, to dysfunctional dopaminergic systems, including Parkinson's disease, attention deficit hyperactivity disorder, and substance abuse. Drugs that modify the DA system are clinically effective in treating symptoms of these diseases or are involved in their manifestation, implicating DA in their etiology. DA signaling and distribution are primarily modulated by the DA transporter (DAT) and by vesicular monoamine transporter (VMAT)-2, which transport DA into presynaptic terminals and synaptic vesicles, respectively. These transporters are regulated by complex processes such as phosphorylation, protein-protein interactions, and changes in intracellular localization. This review provides an overview of 1) the current understanding of DAT and VMAT2 neurobiology, including discussion of studies ranging from those conducted in vitro to those involving human subjects; 2) the role of these transporters in disease and how these transporters are affected by disease; and 3) and how selected drugs alter the function and expression of these transporters. Understanding the regulatory processes and the pathologic consequences of DAT and VMAT2 dysfunction underlies the evolution of therapeutic development for the treatment of DA-related disorders.

Chronic Nicotine Exposure Attenuates Methamphetamine-Induced Dopaminergic Deficits.

Repeated methamphetamine (METH) administrations cause persistent dopaminergic deficits resembling aspects of Parkinson's disease. Many METH abusers smoke cigarettes and thus self-administer nicotine; yet few studies have investigated the effects of nicotine on METH-induced dopaminergic deficits. This interaction is of interest because preclinical studies demonstrate that nicotine can be neuroprotective, perhaps owing to effects involving α4ß2 and α6ß2 nicotinic acetylcholine receptors (nAChRs). This study revealed that oral nicotine exposure beginning in adolescence [postnatal day (PND) 40] through adulthood [PND 96] attenuated METH-induced striatal dopaminergic deficits when METH was administered at PND 89. This protection did not appear to be due to nicotine-induced alterations in METH pharmacokinetics. Short-term (i.e., 21-day) high-dose nicotine exposure also protected when administered from PND 40 to PND 61 (with METH at PND 54), but this protective effect did not persist. Short-term (i.e., 21-day) high-dose nicotine exposure did not protect when administered postadolescence (i.e., beginning at PND 61, with METH at PND 75). However, protection was engendered if the duration of nicotine exposure was extended to 39 days (with METH at PND 93). Autoradiographic analysis revealed that nicotine increased striatal α4ß2 expression, as assessed using [(125)I]epibatidine. Both METH and nicotine decreased striatal α6ß2 expression, as assessed using [(125)I]α-conotoxin MII. These findings indicate that nicotine protects against METH-induced striatal dopaminergic deficits, perhaps by affecting α4ß2 and/or α6ß2 expression, and that both age of onset and duration of nicotine exposure affect this protection.

Nicotine Administration Attenuates Methamphetamine-Induced Novel Object Recognition Deficits.

BACKGROUND: Previous studies have demonstrated that methamphetamine abuse leads to memory deficits and these are associated with relapse. Furthermore, extensive evidence indicates that nicotine prevents and/or improves memory deficits in different models of cognitive dysfunction and these nicotinic effects might be mediated by hippocampal or cortical nicotinic acetylcholine receptors. The present study investigated whether nicotine attenuates methamphetamine-induced novel object recognition deficits in rats and explored potential underlying mechanisms. METHODS: Adolescent or adult male Sprague-Dawley rats received either nicotine water (10-75 µg/mL) or tap water for several weeks. Methamphetamine (4 × 7.5mg/kg/injection) or saline was administered either before or after chronic nicotine exposure. Novel object recognition was evaluated 6 days after methamphetamine or saline. Serotonin transporter function and density and α4ß2 nicotinic acetylcholine receptor density were assessed on the following day. RESULTS: Chronic nicotine intake via drinking water beginning during either adolescence or adulthood attenuated the novel object recognition deficits caused by a high-dose methamphetamine administration. Similarly, nicotine attenuated methamphetamine-induced deficits in novel object recognition when administered after methamphetamine treatment. However, nicotine did not attenuate the serotonergic deficits caused by methamphetamine in adults. Conversely, nicotine attenuated methamphetamine-induced deficits in α4ß2 nicotinic acetylcholine receptor density in the hippocampal CA1 region. Furthermore, nicotine increased α4ß2 nicotinic acetylcholine receptor density in the hippocampal CA3, dentate gyrus and perirhinal cortex in both saline- and methamphetamine-treated rats. CONCLUSIONS: Overall, these findings suggest that nicotine-induced increases in α4ß2 nicotinic acetylcholine receptors in the hippocampus and perirhinal cortex might be one mechanism by which novel object recognition deficits are attenuated by nicotine in methamphetamine-treated rats.

Effect of low doses of methamphetamine on rat limbic-related neurotensin systems.

Administration of methamphetamine (METH) alters limbic-related (LR) neurotensin (NT) systems. Thus, through a D1-receptor mechanism, noncontingent high doses (5-15 mg kg(-1)), and likely self-administration, of METH appears to reduce NT release causing its accumulation and an elevation of NT-like immunoreactivity (NTLI) in limbic-related NT pathways. For comparison, we tested the effect of low doses of METH, that are more like those used in therapy, on NTLI in the core and shell of the nucleus accumbens (NAc and NAs), prefrontal cortex (PFC), ventral tegmental area (VTA), the lateral habenula (Hb) and basolateral amygdala (Amyg). METH at the dose of 0.25 mg kg(-1) in particular, but not 1.00 mg kg(-1), decreased NTLI concentration in all of the LR structures studied, except for the prefrontal cortex; however, these effects were rapid and brief being observed at 5 h but not at 24 h after treatment. In all of the LR areas where NTLI levels were reduced after the low dose of METH, the effect was blocked by pretreatment with either a D1 or a D2 antagonist. Thus, opposite to high doses like those associated with abuse, the therapeutic-like low-dose METH treatment induced reduction in NT tissue levels likely reflected an increase in NT release and a short-term depletion of the levels of this neuropeptide in LR structures, manifesting features comparable to the response of basal ganglia NT systems to similar low doses of METH.

Methamphetamine self-administration attenuates hippocampal serotonergic deficits: role of brain-derived neurotrophic factor.

Preclinical studies suggest that prior treatment with escalating doses of methamphetamine (METH) attenuates the persistent deficits in hippocampal serotonin (5-hydroxytryptamine; 5HT) transporter (SERT) function resulting from a subsequent 'binge' METH exposure. Previous work also demonstrates that brain-derived neurotrophic factor (BDNF) exposure increases SERT function. The current study investigated changes in hippocampal BDNF protein and SERT function in rats exposed to saline or METH self-administration prior to a binge exposure to METH or saline. Results revealed that METH self-administration increased hippocampal mature BDNF (mBDNF) immunoreactivity compared to saline-treated rats as assessed 24 h after the start of the last session. Further, mBDNF immunoreactivity was increased and SERT function was not altered in rats that self-administered METH prior to the binge METH exposure as assessed 24 h after the binge exposure. These results suggest that prior exposure to contingent METH increases hippocampal mBDNF, and this may contribute to attenuated deficits in SERT function.

Neurochemical and behavioral effects of chronic unpredictable stress.

Chronic stress can influence behaviors associated with medial prefrontal cortex (mPFC) function, such as cognition and emotion regulation. Dopamine in the mPFC is responsive to stress and modulates its behavioral effects. The current study tested whether exposure to 10 days of chronic unpredictable stress (CUS) altered the effects of acute elevation stress on dopamine release in the mPFC and on spatial recognition memory. Male rats previously exposed to CUS or nonstressed controls were tested behaviorally, underwent microdialysis to assess mPFC dopamine levels or underwent blood sampling for corticosterone analysis. Dopamine in the mPFC significantly increased in both groups during acute elevation stress compared with baseline levels, but the level was attenuated in CUS rats compared with controls. Control rats exposed to elevation stress immediately before the T-maze test showed impaired performance, whereas CUS rats did not. No group differences were observed in general motor activity or plasma corticosterone levels following elevation stress. The present results indicate that prior exposure to this CUS procedure reduced dopamine release in the mPFC during acute elevation stress and prevented the impairment of performance on a spatial recognition test following an acute stressor. These findings may contribute to an understanding of the complex behavioral consequences of stress.

Changes in Substance Use Diagnoses in the Great Plains during the COVID-19 Pandemic.

As drug overdose mortality rises in the United States, healthcare visits present critical opportunities to mitigate this trend. This study examines changes in healthcare visits for substance use disorders (SUDs) and remission prior to and during the COVID-19 pandemic in the Great Plains, with a focus on identifying the characteristics of those served. Data were analyzed from 109,671 patient visits (mode = one visit per patient), encompassing diverse demographics, including sex, age, race, ethnicity, and geographic location. Visits analyzed included those for Alcohol Use Disorder (AUD), Opioid Use Disorder (OUD), or Stimulant Use Disorder (StUD) and those in remission of these disorders between March 2019 and March 2021. Patient demographic information and geographic factors, like rurality and Medicaid expansion status, were considered, and logistic regression was utilized. Visits were primarily by White (70.83%) and Native American (21.39%) patients, non-Hispanic (91.70%) patients, and males (54.16%). Various demographic, geographic, and temporal trends were observed. Findings indicated that males were more likely to receive an AUD diagnosis, while females were more likely to receive an OUD or StUD diagnosis. Metropolitan-residing patients were more likely to receive an AUD diagnosis, while non-metropolitan patients were more likely to receive an OUD diagnosis. Remission odds increased for StUD during the pandemic but decreased for AUD and OUD. These findings illuminate the demographic and geographic patterns of SUD-related healthcare visits, suggesting critical touchpoints for intervention. The results emphasize the urgent need for targeted healthcare strategies, especially in rural and underserved areas, to address persistent health disparities.

Response of neurotensin basal ganglia systems during extinction of methamphetamine self-administration in rat.

Because of persistent social problems caused by methamphetamine (METH), new therapeutic strategies need to be developed. Thus, we investigated the response of central nervous system neurotensin (NT) systems to METH self-administration (SA) and their interaction with basal ganglia dopamine (DA) pathways. Neurotensin is a peptide associated with inhibitory feedback pathways to nigrostriatal DA projections. We observed that NT levels decreased in rats during extinction of METH SA when lever pressing resulted in intravenous infusions of saline rather than METH. Thus, 6 h after the first session of extinction, NT levels were 53, 42, and 49% of corresponding controls in the anterior dorsal striatum, posterior dorsal striatum, and globus pallidus, respectively. NT levels were also significantly reduced in corresponding yoked rats in the anterior dorsal striatum (64% of control), but not the other structures examined. The reductions in NT levels in the anterior dorsal striatum particularly correlated with the lever pressing during the first session of extinction (r =s; 0.745). These, and previously reported findings, suggest that the extinction-related reductions in NT levels were mediated by activation of D2 receptors. Finally, administration of the neurotensin receptor 1 (NTR1) agonist [PD149163 [Lys(CH2NH)Lys-Pro,Trp-tert-Leu-Leu-Oet]; 0.25 or 0.5 mg/kg] diminished lever pressing during the first extinction session, whereas the NTR1 antagonist [SR48692 [2-[(1-(7-chloro-4-quinolinyl)-5-(2,6-imethoxyphenyl)pyrazol-3-yl)carbonylamino]tricyclo(3.3.1.1.(3.7))decan-2-carboxylic acid]; 0.3 mg/kg per administration] attenuated the reduction of lever pressing during the second to fourth days of extinction. In summary, these findings support the hypothesis that some of the endogenous basal ganglia NT systems contribute to the elimination of contingent behavior during the early stages of the METH SA extinction process.

The effects of methamphetamine self-administration on cortical monoaminergic deficits induced by subsequent high-dose methamphetamine administrations.

Preclinical models suggest that repeated high-dose methamphetamine (METH) exposures, administered in a "binge-like" pattern, acutely decrease norepinephrine (NE), and acutely and persistently decrease serotonin (5-hydroxytryptamine; 5HT) content in the frontal cortex. However, the impact of METH self-administration on this region is unknown. Because of the importance of the monoaminergic neurons in the frontal cortex to a variety of cognitive and addictive processes, effects of METH self-administration on cortical NE and 5HT content were assessed. Results revealed several novel findings. First, METH self-administration decreased cortical NE content as assessed 24 h after last exposure. Consistent with previous preclinical reports after a binge METH regimen, this decrease was reversed 8 days after the final METH exposure. Second, and in contrast to our previous reports involving the hippocampus or striatum, METH self-administration caused persistent decreases in 5HT content as assessed 8 days after the final METH exposure. Of note, the magnitude of this decrease (≈ 20%) was less than that observed typically after a binge METH treatment. Third, prior METH self-administration attenuated METH-induced serotonergic deficits as assessed 7 days, but not 1 h, following a neurotoxic METH regimen. No protection was observed when the binge exposure occurred 15 days after the last self-administration session. Taken together, these data demonstrate important and selective alterations in cortical serotonergic neuronal function subsequent to METH self-administration. These data provide a foundation to investigate complex questions involving "resistance" to the persistent deficits caused by neurotoxic METH exposure and frontal cortical function.

Changes in buprenorphine visits in frontier and remote locations: Effects of the SARS-CoV-2 pandemic.

Background: The pandemic has changed many aspects of healthcare, including the treatment of people with opioid use disorder with buprenorphine. Prior to the pandemic, rural health disparities existed in the accessibility of this treatment. Rural and frontier areas of the United States, particularly the Great Plains, had few or no providers of this evidence-based treatment. This study aimed to investigate how access to buprenorphine changed in the Great Plains during the pandemic. Methods: This retrospective observational study compared the number of weekly patient appointments resulting in a buprenorphine prescription for 55 weeks before the start of the SARS-CoV-2 pandemic and 55 weeks after. Electronic health records of the largest rural health provider in the Great Plains were queried. Patients were categorized as coming from a frontier location or a non-frontier location based on the home address provided at the visit. The USDA defines frontier as communities that are small and distant from urban centers. Time series analysis was utilized to understand changes in weekly visits during this period. Results: A significant increase in weekly buprenorphine visits occurred after the pandemic's start. Further, females and people from frontier locations had significantly higher numbers of buprenorphine visits. Conclusions: In an area of the country with low pre-existing access to buprenorphine treatment for opioid use disorder, increases in buprenorphine visits were found after the pandemic began. This was particularly true of females who reside in frontier areas. Pandemic-related changes may have reduced barriers to this critical treatment, especially among rural populations.

Unique SARS-CoV-2 Variants, Tourism Metrics, and B.1.2 Emergence in Early COVID-19 Pandemic: A Correlation Analysis in South Dakota.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus, which is the source of the coronavirus disease 2019 (COVID-19), was declared a pandemic in the March of 2020. Travel and tourism were severely impacted as restrictions were imposed to help slow the disease spread, but some states took alternative approaches to travel restrictions. This study investigated the spread of COVID-19 in South Dakota during the early pandemic period to better understand how tourism affected the movement of the virus within the region. Sequences from the fall of 2020 were retrieved from public sources. CDC and other sources were used to determine infections, deaths, and tourism metrics during this time. The data were analyzed using correlation and logistic regression. This study found that the number of unique variants per month was positively correlated with hotel occupancy, but not with the number of cases or deaths. Interestingly, the emergence of the B.1.2 variant in South Dakota was positively correlated with increased case numbers and deaths. Data show that states with a shelter-in-place order were associated with a slower emergence of the B.1.2 variant compared to states without such an order, including South Dakota. Findings suggest complex relationships between tourism, SARS-CoV-2 infections, and mitigation strategies. The unique approach that South Dakota adopted provided insights into the spread of the disease in areas without state-wide restrictions. Our results suggest both positive and negative aspects of this approach. Finally, our data highlight the need for future surveillance efforts, including efforts focused on identifying variants with known increased transmission potential to produce effective population health management.

Analysis of Wastewater Samples to Explore Community Substance Use in the United States: Pilot Correlative and Machine Learning Study.

BACKGROUND: Substance use disorder and associated deaths have increased in the United States, but methods for detecting and monitoring substance use using rapid and unbiased techniques are lacking. Wastewater-based surveillance is a cost-effective method for monitoring community drug use. However, the examination of the results often focuses on descriptive analysis. OBJECTIVE: The objective of this study was to explore community substance use in the United States by analyzing wastewater samples. Geographic differences and commonalities of substance use were explored. METHODS: Wastewater was sampled across the United States (n=12). Selected drugs with misuse potential, prescriptions, and over-the-counter drugs and their metabolites were tested across geographic locations for 7 days. Methods used included wastewater assessment of substances and metabolites paired with machine learning, specifically discriminant analysis and cluster analysis, to explore similarities and differences in wastewater measures. RESULTS: Geographic variations in the wastewater drug or metabolite levels were found. Results revealed a higher use of methamphetamine (z=-2.27, P=.02) and opioids-to-methadone ratios (oxycodone-to-methadone: z=-1.95, P=.05; hydrocodone-to-methadone: z=-1.95, P=.05) in states west of the Mississippi River compared to the east. Discriminant analysis suggested temazepam and methadone were significant predictors of geographical locations. Precision, sensitivity, specificity, and F1-scores were 0.88, 1, 0.80, and 0.93, respectively. Finally, cluster analysis revealed similarities in substance use among communities. CONCLUSIONS: These findings suggest that wastewater-based surveillance has the potential to become an effective form of surveillance for substance use. Further, advanced analytical techniques may help uncover geographical patterns and detect communities with similar needs for resources to address substance use disorders. Using automated analytics, these advanced surveillance techniques may help communities develop timely, tailored treatment and prevention efforts.

Methamphetamine self-administration causes persistent striatal dopaminergic alterations and mitigates the deficits caused by a subsequent methamphetamine exposure.

Preclinical studies have demonstrated that repeated methamphetamine (METH) injections (referred to herein as a "binge" treatment) cause persistent dopaminergic deficits. A few studies have also examined the persistent neurochemical impact of METH self-administration in rats, but with variable results. These latter studies are important because: 1) they have relevance to the study of METH abuse; and 2) the effects of noncontingent METH treatment do not necessarily predict effects of contingent exposure. Accordingly, the present study investigated the impact of METH self-administration on dopaminergic neuronal function. Results revealed that self-administration of METH, given according to a regimen that produces brain METH levels comparable with those reported postmortem in human METH abusers (0.06 mg/infusion; 8-h sessions for 7 days), decreased striatal dopamine transporter (DAT) uptake and/or immunoreactivity as assessed 8 or 30 days after the last self-administration session. Increasing the METH dose per infusion did not exacerbate these deficits. These deficits were similar in magnitude to decreases in DAT densities reported in imaging studies of abstinent METH abusers. It is noteworthy that METH self-administration mitigated the persistent deficits in dopaminergic neuronal function, as well as the increases in glial fibrillary acidic protein immunoreactivity, caused by a subsequent binge METH exposure. This protection was independent of alterations in METH pharmacokinetics, but may have been attributable (at least in part) to a pretreatment-induced attenuation of binge-induced hyperthermia. Taken together, these results may provide insight into the neurochemical deficits reported in human METH abusers.

Methamphetamine self-administration acutely decreases monoaminergic transporter function.

Numerous preclinical studies have demonstrated that noncontingent methamphetamine (METH) administration rapidly decreases both dopamine (DA) transporter (DAT) and vesicular monoamine-2 transporter (VMAT-2) function. Because of the importance of transporter function to the abuse and neurotoxic liabilities of METH, and previous research indicating that the effects of noncontingent METH treatment do not necessarily predict effects of contingent exposure, the present study examined the acute impact of METH self-administration on these transporters. Results revealed that five days of METH self-administration (4 h/session; 0.06 mg/infusion) decreased DAT and VMAT-2 activity, as assessed in synaptosomes and vesicles, respectively, prepared from striatal tissue 1 h after the final self-administration session. METH self-administration increased core body temperatures as well. Brain METH and amphetamine (AMPH) levels, assessed 1 h after the final self-administration session, were approximately twice greater in high-pressing rats compared to low-pressing rats despite similar changes in DAT function. In conclusion, the present manuscript is the first to describe transporter function and METH/AMPH levels after self-administration in rodents. These data provide a foundation to investigate complex questions including how the response of dopaminergic systems to METH self-administration contributes to contingent-related processes such as dependence.

Population Health Metrics During the Early Stages of the COVID-19 Pandemic: Correlative Pilot Study.

BACKGROUND: COVID-19 has caused nearly 1 million deaths in the United States, not to mention job losses, business and school closures, stay-at-home orders, and mask mandates. Many people have suffered increased anxiety and depression since the pandemic began. Not only have mental health symptoms become more prevalent, but alcohol consumption has also increased during this time. Helplines offer important insight into both physical and mental wellness of a population by offering immediate, anonymous, cheap, and accessible resources for health and substance use disorders (SUD) that was unobstructed by many of the mandates of the pandemic. Further, the pandemic also launched the use of wastewater surveillance, which has the potential for tracking not only population infections but also consumption of substances such as alcohol. OBJECTIVE: This study assessed the feasibility of using multiple public surveillance metrics, such as helpline calls, COVID-19 cases, and alcohol metabolites in wastewater, to better understand the need for interventions or public health programs in the time of a public health emergency. METHODS: Ethanol metabolites were analyzed from wastewater collected twice weekly from September 29 to December 4, 2020, in a Midwestern state. Calls made to the helpline regarding housing, health care, and mental health/SUD were correlated with ethanol metabolites analyzed from wastewater samples, as well as the number of COVID-19 cases during the sampling period. RESULTS: Correlations were observed between COVID-19 cases and helpline calls regarding housing and health care needs. No correlation was observed between the number of COVID-19 cases and mental health/SUD calls. COVID-19 cases on Tuesdays were correlated with the alcohol metabolite ethyl glucuronide (EtG). Finally, EtG levels were negatively associated with mental health/SUD helpline calls. CONCLUSIONS: Although helpline calls provided critical services for health care and housing-related concerns early in the pandemic, evidence suggests helpline calls for mental health/SUD-related concerns were unrelated to COVID-19 metrics. Instead, COVID metrics were associated with alcohol metabolites in wastewater. Although this research was formative, with continued and expanded monitoring of population metrics, such as helpline usage, COVID-19 metrics, and wastewater, strategies can be implemented to create precision programs to address the needs of the population.

Effect of methamphetamine self-administration on neurotensin systems of the basal ganglia.

Methamphetamine (METH) dependence causes alarming personal and social damage. Even though many of the problems associated with abuse of METH are related to its profound actions on dopamine (DA) basal ganglia systems, there currently are no approved medications to treat METH addiction. For this reason, we and others have examined the METH-induced responses of neurotensin (NT) systems in the basal ganglia. This neuropeptide is associated with inhibitory feedback pathways to nigrostriatal DA projections, and NT tissue levels are elevated in response to high doses of noncontingent METH because of its increased synthesis in the striatonigral pathway. The present study reports the contingent responses of NT in the basal ganglia to self-administration of METH (SAM). Intravenous infusions of METH linked to appropriate lever-pressing behavior by rats significantly elevated NT content in both dorsal striatum (210%) and substantia nigra (202%). In these same structures, NT levels were also elevated in yoked METH animals (160 and 146%, respectively) but not as much as in the SAM rats. These effects were blocked by a D1, but not D2, antagonist. A NT agonist administered before the day 5 of operant behavior blocked lever-pressing behavior in responding rats, but a NT antagonist had no significant effect on this behavior. These are the first reports that NT systems associated with striatonigral pathway are significantly altered during METH self-administration, and our findings suggest that activation of NT receptors during maintenance of operant responding reduces the associated lever-pressing behavior.