Clinician perspectives on adolescent cannabis-related beliefs and behaviors following recreational cannabis legalization.

BACKGROUND: As more states legalize cannabis, studies are needed to understand the potential impacts of recreational cannabis legalization (RCL) on adolescents from the perspective of clinicians who care for them. METHODS: This qualitative study characterized clinician perspectives on whether cannabis legalization is associated with changes in adolescents' cannabis use beliefs, behaviors, and consequences. Semi-structured qualitative interviews were conducted with 32 clinicians in a large healthcare organization from 9/6/2022-12/21/2022. Video-recorded interviews were transcribed and analyzed using thematic analysis. RESULTS: The 32 participants (56.3 % female, mean [SD] age, 45.9 [7.6] years; 65.3 % non-Hispanic White) were from Addiction Medicine (n = 13), Psychiatry/Mental Health (n = 7), Pediatrics (n = 5), and the Emergency Department (n = 7). Clinicians described post-RCL increases in adolescent cannabis use, use of non-combustible modes and high-potency products, and younger age of first use. Clinicians reported social, physical, and policy changes, including changes in social norms, appealing advertisements, marketing, and easier access. Many noted fewer perceived harms among adolescents and greater self-medication post-RCL. They described how RCL contributed to increased parental cannabis use and permissiveness around adolescent use. Finally, many described post-RCL increases in cannabis hyperemesis syndrome, and several noted increased cannabis-related psychosis and acute intoxication, and decreased court-mandated treatment. CONCLUSIONS: Clinicians from diverse specialties described post-RCL increases in adolescent cannabis use and cannabis-related consequences, alongside changes in social norms, access, marketing and advertisements, and decreased perceptions of harms. Findings can inform strategies to support adolescents in the context of increased cannabis availability and acceptability post-legalization and support the development of hypotheses for broader-scale quantitative work.

Structure and dynamics of a pentameric KCTD5/CUL3/Gßγ E3 ubiquitin ligase complex.

Heterotrimeric G proteins can be regulated by posttranslational modifications, including ubiquitylation. KCTD5, a pentameric substrate receptor protein consisting of an N-terminal BTB domain and a C-terminal domain, engages CUL3 to form the central scaffold of a cullin-RING E3 ligase complex (CRL3KCTD5) that ubiquitylates Gßγ and reduces Gßγ protein levels in cells. The cryo-EM structure of a 5:5:5 KCTD5/CUL3NTD/Gß1γ2 assembly reveals a highly dynamic complex with rotations of over 60° between the KCTD5BTB/CUL3NTD and KCTD5CTD/Gßγ moieties of the structure. CRL3KCTD5 engages the E3 ligase ARIH1 to ubiquitylate Gßγ in an E3-E3 superassembly, and extension of the structure to include full-length CUL3 with RBX1 and an ARIH1~ubiquitin conjugate reveals that some conformational states position the ARIH1~ubiquitin thioester bond to within 10 Å of lysine-23 of Gß and likely represent priming complexes. Most previously described CRL/substrate structures have consisted of monovalent complexes and have involved flexible peptide substrates. The structure of the KCTD5/CUL3NTD/Gßγ complex shows that the oligomerization of a substrate receptor can generate a polyvalent E3 ligase complex and that the internal dynamics of the substrate receptor can position a structured target for ubiquitylation in a CRL3 complex.

Development of the Protective Strategies for Psychedelics Scale: A novel inventory to assess safety strategies in the context of psychedelics.

BACKGROUND: Individuals who use psychedelics take efforts to mitigate unintended consequences. Despite the demonstrated utility of analogous protective behavioral strategies (PBS) assessments for other substances, no standardized scale exists to capture these protective strategies for psychedelic use. OBJECTIVE: The present study addresses a notable gap concerning the assessment of psychedelic use, specifically by developing a scale measuring the protective strategies employed around use, called the Protective Strategies for Psychedelics Scale (PSPS). METHODS: A sample (Mage = 36.85 years old, standard deviation = 10.3; male = 61.9%; White = 85.2%) of 434 adults with lifetime use of psychedelics reported on initial qualitatively developed items for the PSPS, PBS scales for cannabis and alcohol, and use of alcohol, cannabis, and psychedelics. RESULTS: Iterative principal components analyses began with 37 items and yielded a 32-item two-factor solution demonstrating excellent internal reliability (Cronbach's α = .95) and accounted for 51.3% of the variance. Nineteen items loaded on PSPS factor 1, which focused on long-term preparation, emphasizing strategies focused on mood/intentions, preparing the substance, environment, and scheduling episode of use; 13 items loaded on factor 2, which focused on short-term preparation, highlighting strategies surrounding social context, health, and other substances. The PSPS demonstrated convergent validity with validated PBS scales for cannabis and alcohol (r = 0.71-0.79, p < 0.001), and was moderately associated with lifetime psychedelic use (r = 0.28, p < 0.001). CONCLUSION: The PSPS demonstrates promising psychometric properties, and future work validating the scale for diverse samples across research and clinical settings is warranted.

Exploring preferences for different modes of cannabis use during early pregnancy: A qualitative study.

OBJECTIVE: Rates of prenatal cannabis use are rising, yet little is known about modes of cannabis use during pregnancy. This focus group study with pregnant individuals aimed to examine use patterns and perceptions regarding common modes of prenatal cannabis use. METHOD: Kaiser Permanente Northern California pregnant adult patients who identified as White or Black and self-reported cannabis use during pregnancy were recruited to participate (N = 53; 40% Black, 60% White; Meanage = 30.3, SD = 5.2). Eighteen focus groups with race-concordant facilitators followed a semi-structured format that queried participants on their prenatal cannabis use, including preferred modes of use (e.g., vapes, blunts, dabs, joints, edibles, topicals, pipes). Focus group discussions were coded and analyzed using a general inductive approach. RESULTS: A range of modes were preferred, with no single mode predominant. Participants' preferences aligned with four themes: perceived effects and benefits of cannabis, health and safety, convenience and familiarity, and partner and friend influences. Participants sought modes that were accessible and familiar, provided consistent and quick relief for pregnancy-related symptoms, were aligned with partners or friends, and minimized perceived risks while also providing symptom relief. Participants desired evidence-based information about mode safety to better inform mode selection during pregnancy. CONCLUSIONS: A range of personal and social factors influenced mode preferences during pregnancy. Many participants desired to reduce harms and use cannabis more safely in pregnancy but received little mode-specific information to guide these preferences. Further research identifying mode-specific risks is needed to guide harm reduction approaches during pregnancy.

Cannabis Use Among U.S. Military Veterans Following Residential Substance Use Disorder Treatment.

INTRODUCTION: Use rates of cannabis, a substance associated with a host of comorbid physical and mental health concerns, continue to rise for military veterans. Despite this prevalence, descriptive patterns of use among veterans and research on treatment factors that predict cannabis outcomes are lacking. This study aimed to conduct a descriptive profile of veterans who endorse cannabis use, compare veterans endorsing cannabis use to those who do not endorse use, and investigate what factors (other substance use, psychiatric symptoms, and treatment outcomes) predicted return to cannabis use following residential treatment. MATERIALS AND METHODS: The study was a secondary data analysis of a longitudinal sample of U.S. military veterans (N = 200, 193 males, Mage = 50.14, SD = 9) participating in residential substance use disorder treatment through a Veterans Affairs medical center. Interview, survey, and electronic health data were collected over 12 months. Analyses included descriptive and frequency statistics to identify patterns in cannabis use behaviors and motives, independent t-tests to examine differences between the cannabis-using group and non-using group, and a series of univariate logistic regressions to examine potential predictors for cannabis use after treatment discharge. RESULTS: Lifetime cannabis use was common among veterans (77.5%), and 29.5% reported use during the study. On average, veterans had made one quit attempt before treatment entry. Veterans who endorsed cannabis use consumed more alcohol in the past 30 days at baseline and reported less impulse control and less confidence in maintaining abstinence at discharge. Length of stay in the residential program and no diagnosis of Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV cannabis use disorder criteria predicted post-treatment cannabis use such that veterans who remained in the program longer were more likely to abstain from cannabis use following treatment, and those who did not meet DSM-IV cannabis use disorder criteria were more likely to use following treatment. CONCLUSIONS: Identification of relevant risk factors and treatment processes, such as impulse control, confidence in treatment, and length of stay in treatment, provides practical recommendations for future intervention efforts. This study calls for further examination of cannabis use outcomes among veterans, particularly those participating in substance use treatment.

Perceptions About Cannabis Following Legalization Among Pregnant Individuals With Prenatal Cannabis Use in California.

Importance: As rates of prenatal cannabis use increase and cannabis legalization spreads across the US, studies are needed to understand the potential impacts of legalization from the perspectives of pregnant individuals who use cannabis. Objective: To characterize pregnant individuals' perspectives on legalization of cannabis for adult use in California (effective in 2018) in relation to prenatal cannabis use behaviors and beliefs. Design, Setting, and Participants: This qualitative study was conducted in Kaiser Permanente Northern California, a large health care system with universal screening for self-reported cannabis use at entrance to prenatal care. Eighteen semistructured focus groups were conducted from November 17 to December 17, 2021, using a secure video conferencing platform with Black and White pregnant participants who self-reported cannabis use during early pregnancy. Data were analyzed from March to June 2022. Main Outcomes and Measures: Video-recorded interviews were transcribed and analyzed using thematic analysis to identify major themes and subthemes. Results: Among 53 participants (mean [SD] age, 30.3 [5.2] years), 23 (43%) identified as non-Hispanic Black and 30 (57%) identified as non-Hispanic White; 16 participants (30%) reported continued cannabis use at the time of recruitment. Major themes regarding the perceived impact of legalization included easier access (via retailers and delivery), greater acceptance (including reduced stigma and more discussions about prenatal cannabis use with health care practitioners), and trust in cannabis retailers (including safety and effectiveness of diverse products sold and perceptions of cannabis retailer employees as knowledgeable, nonjudgmental, and caring). Responses were mixed about whether retailer marketing and advertising were associated with prenatal cannabis use and whether legalization resulted in reduced concerns about Child Protective Services involvement. Conclusion and Relevance: The findings of this qualitative study suggest pregnant individuals perceive cannabis legalization as having reduced barriers to prenatal cannabis use and that legalization has created challenges and opportunities for supporting the health of pregnant individuals. The results of this qualitative study highlight key areas that can be further explored in future educational materials, public health campaigns, and policy adaptations to address increasing rates of prenatal cannabis use.

Cannabis's Link to Schizotypy: Phenomenon, Measurement Bias, or Delusion?

Links between cannabis use and psychosis generate research and media attention. Cannabis users have outscored non-users on the Schizotypal Personality Questionnaire-Brief (SPQ-B) in multiple studies, but previous work suggests that groups do not differ if biased items are removed. The present study examined links between schizotypal personality and cannabis use in a large sample recruited from Amazon's MTurk platform (N = 705). Over 500 participants reported lifetime cannabis exposure. Of those, 259 participants reported current cannabis use, and on average, used 4.53 days per week. Users and non-users failed to differ significantly on total SPQ-B scores or any of the three established subscales. The null results inspired a re-examination of the SPQ-B's factor structure, which identified a novel 3-factor solution (difficulty opening up to others, hyperawareness, and odd or unusual behavior). Only the "odd or unusual behavior" factor showed cannabis-related differences, but a differential item functioning test revealed that one subscale item showed potential bias against users. Removing this item diminished group differences. These results suggest that links between schizotypy and cannabis use require cautious interpretation with careful attention to potential measurement bias. In addition, the SPQ-B might have an alternative factor structure that could help answer important questions in psychopathology.

Expectancies for Cannabis- Induced Emotional Breakthrough, Mystical Experiences and Changes in Dysfunctional Attitudes: Perceptions of the Potential for Cannabis-Assisted Psychotherapy for Depression.

Psychedelic-assisted psychotherapy has established antidepressant effects. Cannabis users appear to expect high doses administered in a session much like psychedelic-assisted psychotherapy to create comparable subjective effects. The current studies explored expectations of antidepressant effects of such cannabis-assisted sessions to replicate and extend previous work. Users not only expected a cannabis-assisted psychotherapy session to decrease depression, but also to alter some of the same mediators of psychedelic or psychological treatments. Over 500 participants in Study I envisioned a cannabis-assisted therapy session akin to those used in psychedelic therapies and reported the effects that they expected on depression as well as relevant subjective reactions. A second sample of over 500 participants responded to identical measures and an index of dysfunctional attitudes that appears to mediate antidepressant effects of psychotherapy. Expectancies of cannabis-induced antidepressant effects covaried with expected psychedelic effects. Participants also envisioned that cannabis-assisted therapy would alter dysfunctional attitudes, which served as a separate, unique path to expected antidepressant effects unrelated to the subjective effects of psychedelics. These results add support to arguments for relevant clinical trials of cannabis-assisted psychotherapy and suggest that cannabis users would expect it to work in ways similar to psychedelics as well as cognitive therapy.

Policing Pot: State-Level Cannabis Arrests Increase Perceived Risks and Costs but Not Use.

Legal sanctions are purported to play a role in cannabis use and related consequences. General models of deterrence suggest that increases in arrests should decrease consumption by heightening perceptions of the negative consequences of use as well as the likelihood and severity of penalties. The present study examined if arrests resulting from cannabis possession relate to cannabis consumption, perceptions of use, and likelihood and severity of related penalties. Combining data from the National Survey on Drug Use and Health with the FBI Uniform Crime Report (2002-2013) allowed for the estimation of a series of fixed- effects models that compare rates of arrests and perceived risks of aggregate rates of self-reported use at the state-level over time. Forty-nine states reported data (N = 592 state-years). Cannabis-related arrest rates (ratio of possession arrests for state/state population times 1,000) ranged from 0.04 - 5.63. Increases in cannabis-related arrests were associated with heightened perceptions of risk from use (b = .80 [-.16, 1.8], p < .05); but this association was non-significant in the model omitting states that legalized recreational cannabis in 2012. Arrests related to greater perceptions of the severity of potential penalties, including community service (b = .54 [.24, .85], p < .05), probation (b = .85 [.44, 1.3], p < .001), and prison sentences (b = .25 [.02, .5], p < .05). Arrest rates were not associated with cannabis use (b = -.25 [-.52, .05], p > .05) or the proportion of new initiates (b = -.02 [-.08, .05], p > .05). We conclude that increased arrests are associated with perceptions of negative consequences and penalty but appear unrelated to actual use. This study highlights the need to re-examine the utility of punitive approaches to reduce the public health burden posed by substance use.

Packing cannabis, pouring alcohol: Validating a free-pack assessment among college students using cannabis.

Objective: Long-standing challenges in quantifying cannabis use make assessment difficult, potentially complicating attempts to minimize harm. Our study investigated how accurately undergraduates who use substances estimate amounts of alcohol through a behavioral pouring task. We also aimed to validate a free pack assessment in which participants similarly estimated amounts of cannabis. We further examined how estimations related to consequences and protective behavioral strategies (PBS). Methods: Participants completed a free pour task and a modified free "pack" task to measure out and estimate quantities of alcohol and cannabis, and self-reported use, problems, PBS, and social context (N = 264; Mage = 19.2, 67.10% Female, 46.20% White). Results: Both tasks indicated high rates of misestimating amounts. Over 80% of the sample misestimated alcohol and cannabis amounts by more than 10%. Students typically underestimated the actual amount of alcohol that they poured, but the trend was opposite for cannabis. Discrepancies in packing joints decreased as quantity-specific cannabis PBS increased, but increased with more frequent cannabis use. Both alcohol and cannabis PBS decreased their respective consumption and negative consequences. Conclusions: A considerable proportion of young adults inaccurately estimate quantities, which is related to negative outcomes. Discrepancies are associated with problems, and interventions may benefit from targeting improvements in accuracy to prevent future harms and enhance protective strategies for specific substance use methods. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Cannabis-induced oceanic boundlessness.

BACKGROUND: Despite tetrahydrocannabinol (THC)'s reputation for creating dramatic effects at high doses, empirical work rarely addresses cannabis's impact on subjective responses common to the tryptamine psychedelics. We focused on these effects because they have preceded and covaried with the therapeutic impact of psilocybin in previous work. AIMS: The current study examined if self-reported responses to cannabis products might parallel those found in clinical trials of psilocybin administration. We also investigated if measures of demographics and cannabis use might correlate with these responses. METHODS: Participants reported the subjective effect of their highest THC experience using 27 items that assess oceanic boundlessness, a correlate of mystical experiences. They also answered infrequency items and questions on demographics and cannabis consumption. RESULTS: In an effort to address concerns about replication, we divided respondents who passed infrequency items into two random samples. Self-reported "breakthrough" experiences were significantly greater than zero but significantly lower than those reported in randomized clinical trials of psilocybin (17-19% vs. 59%). Total scores covaried with perceived dosages of THC, but only in one sample. Heavier users of cannabis reported lower scores. CONCLUSIONS: Self-report data suggest that high doses of cannabis can create subjective effects comparable to those identified in trials of psilocybin that precede relief from cancer-related distress, treatment-resistant depression, alcohol problems, and cigarette dependence. Given the disparate mechanisms of action, comparing THC-induced to psilocybin-induced effects might improve our understanding of the mechanisms underlying subjective experiences. This work might also support the development of a cannabis-assisted psychotherapy comparable to psilocybin-assisted psychotherapy.

Factor analysis of a short form of the Protective Behavioral Strategies for Marijuana scale.

OBJECTIVE: The Protective Behavioral Strategies for Marijuana Scale (PBSM), a 17-item scale targeting strategies for mitigating the negative consequences of cannabis use, highlights a range of behaviors that can reduce harm beyond straightforward decreases in quantity or frequency. The 17-item scale's factor structure remains under-examined but could reveal meaningful distinctions among strategies. This study aimed to confirm the factor structure of the short form of the PBSM. METHODS: This study recruited cannabis-using undergraduates (N = 454,Mage = 19.6, 68.8% female, 39% White), who reported using cannabis approximately 2.3 days per week with mild cannabis-related consequences (CAPQ; M = 9.74). RESULTS: A confirmatory factor analysis demonstrated poor fit for the one-factor model of the PBSM, prompting an exploratory factor analysis. Analyses revealed two internally reliable factors: a "Quantity" factor, strategies specific to mitigating overuse and limiting amounts consumed and an "Context" factor loosely related to troubles with others. This two-factor model accounted for over half of the total variance; invariance testing indicated reduced fit as models became more restrictive. Though each of the factors covaried negatively with both days of use and problems, Context had a stronger relation to both variables compared to Quantity. Only Context predicted fewer cannabis problems and use. CONCLUSIONS: The two-factor solution suggests further work on the psychometric properties of the scale could provide heuristic information to allow for more nuanced approaches in clinical and research settings. Theoretically, each factor might have novel links to some constructs but not others in ways that could assist harm-reduction strategies and treatment.

Age-Related Differences in Cannabis Product Use.

Cannabis use varies with age and gender, but less is known regarding specific product choices. Previous work suggests that older adults are inclined to stick to the more "classic" and familiar, while "novel" products are more likely to appeal to younger populations. We examined cross-sectional, retrospective data to determine whether the type of cannabis products used varied according to participant age (N = 1406, 71.3% female). The extensive list of products included: loose flower, pre-rolled joints, edibles, concentrates, oil vaporizers (vape pens), dry vaporizers, tinctures, topicals, and ingestible oils. Overall, rates of use for cannabis-infused ingestible oils, topicals, and tinctures are the lowest and show no age or gender-related differences. In contrast, the use of pre-rolled joints, vape pens, and edibles tends to decrease with age. Loose flower and dry vaporizer use also decrease with age, although less consistently. These age-related differences in product choices can facilitate prevention and treatment efforts toward specific populations. While harm-reduction efforts targeting loose flower and edible products would benefit all age groups, those targeting concentrates might focus only on younger users. On the other hand, learning about concentrates might be beneficial for older medical users due to their larger THC doses and rapid onset.

Gender-based differential item functioning in the Cannabis-Associated Problems Questionnaire: A replication and extension.

BACKGROUND: Gender bias in measures of cannabis problems may differentially affect how men and women endorse items. This gender invariance might mask, exaggerate, or otherwise obscure true distinctions in experiences of cannabis consequences. METHODS: The Cannabis-Associated Problems Questionnaire (CAPQ), a measure of interpersonal deficits, occupational impairment, psychological issues, and physical side effects related to cannabis use, contained items with gender-based differential item functioning (DIF) in previous work-a finding we aim to replicate and extend (Lavender, Looby, & Earleywine, 2008). RESULTS: In a sample of 4053 cannabis users, gender differences were apparent in global scores on the CAPQ. A DIF analysis revealed two gender-biased items, including one identified previously. Removal of these items did not significantly alter the scale's relation to cannabis use. Gender differences on the CAPQ persisted after removal of the two problematic items, indicating true gender differences still exist in men and women's experiences of cannabis-related consequences. Gender appeared to significantly contribute to scores on the full CAPQ and the short-form of the CAPQ with biased item removed, even after controlling for indices of cannabis use. CONCLUSIONS: These findings suggest that the CAPQ evidences less gender bias than previously thought, perhaps due to diminishing gender-based stereotypes. Future work might opt to use the short form of the CAPQ to minimize gender-based DIF. In addition, potential biases in measures of substance use problems deserve more attention.

Confirming Savoring's Link to Fewer Cannabis Problems.

Savoring has covaried inversely with cannabis problems and moderated the association between cannabis use and negative consequences related to use. Research has not yet addressed the acceptability of savoring interventions for cannabis users. The present study aimed to replicate the finding of savoring as a protective factor against problems for cannabis users. The second aim of the study was to examine preferences for a savoring intervention among problem-endorsing cannabis users. We sampled 447 (63.3% female) problem users who self-reported cannabis use, cannabis problems, savoring beliefs, and preferences for cannabis use interventions. On average, our sample reported using cannabis 4.7 days per week and 16.03 times per month, with men endorsing significantly more cannabis-related problems than women. Savoring did increase as problems decreased, but the moderator effect did not replicate. Problem cannabis users preferred a savoring intervention to a typical harm reduction intervention across all sampled demographics, with one notable exception: women were 1.73 times more likely to prefer a savoring intervention. Our findings confirmed that cannabis problems decrease as savoring increases and identified a preference for a savoring intervention among problem users.

Ayahuasca's Antidepressant Effects Covary with Behavioral Activation as Well as Mindfulness.

Ayahuasca, a plant-based hallucinogen that serves as a spiritual medicine in South America, has improved depression in at least one placebo-controlled clinical trial. Case studies suggest that dramatic behavioral changes often follow the Ayahuasca ceremony, but most explanations of antidepressant effects focus on changes in mindfulness. This study investigated whether both mindfulness and behavioral activation might contribute to these anti-depressant effects. We surveyed individuals (N = 152) about their changes in depressive symptoms, behavioral activation, and mindfulness after an Ayahuasca experience. Mindfulness was strongly associated with reduced depression severity (r = - .670, p < .001), while behavioral activation was moderately linked (r = - .474, p < .001). Changes in depressive symptoms (Center for Epidemiological Sciences Depression Short Form [CES-D-10]) covaried with subscales from the Five Facet Mindfulness Questionnaire [FFMQ] and Experiences Questionnaire [EQ], confirming previous findings (ß = -.57, 95% CI -5.70, -3.25), p < .001). In addition, a modification of the Behavioral Activation for Depression Scale-Short Form [BADS-SF] accounted for significant unique variance in the improvements in depression (ß = - .16, 95% CI -6.32, -0.08), p < .05). Changes in behavioral activation likely serve as a mechanism underlying Ayahuasca's antidepressant effects. Future clinical trials could benefit from tracking behavioral activation.

The Role of Impulsivity and Expectancies in Predicting Marijuana Use: An Application of the Acquired Preparedness Model.

Impulsivity and substance use covary. Smith and Anderson's acquired preparedness model proposes that impulsivity predicts substance use through a mediational model such that substance use expectancies mediate the relation between impulsivity and drug use. The present study seeks to examine the relation between positive urgency, an important component of impulsivity with specific relations to substance use behavior, marijuana expectancies, and marijuana use patterns. The study focused on a sample of frequent marijuana users (n = 3,616) and assessed positive urgency using the UPPS-P, expectancies using the Biphasic Marijuana Effects Scale, an adapted form of the Biphasic Alcohol Effects Scale to measure the sedative and stimulant properties of marijuana, and also assessed use patterns. Findings suggest that stimulant expectancies predict heavier, more frequent marijuana use than sedative expectancies and that marijuana expectancies vary based on the limb of marijuana intoxication. Examination of the acquired preparedness model revealed that positive urgency's link to marijuana use was fully mediated by expectancies.

Behavioral phenotyping and dopamine dynamics in mice with conditional deletion of the glutamate transporter GLT-1 in neurons: resistance to the acute locomotor effects of amphetamine.

RATIONALE: GLT-1 is the major glutamate transporter in the brain and is expressed predominantly in astrocytes but is also present in excitatory axon terminals. To understand the functional significance of GLT-1 expressed in neurons, we generated a conditional GLT-1 knockout mouse and inactivated GLT-1 in neurons using Cre-recombinase expressed under the synapsin 1 promoter, (synGLT-1 KO). OBJECTIVES: Abnormalities of glutamate homeostasis have been shown to affect hippocampal-related behaviors including learning and memory as well as responses to drugs of abuse. Here, we asked whether deletion of GLT-1 specifically from neurons would affect behaviors that assessed locomotor activity, cognitive function, sensorimotor gating, social interaction, as well as amphetamine-stimulated locomotor activity. METHODS/RESULTS: We found that the neuronal GLT-1 KO mice performed similarly to littermate controls in the behavioral tests we studied. Although performance in open field testing was normal, the acute locomotor response to amphetamine was significantly blunted in the synGLT-1 KO (40% of control). We found no change in amphetamine-stimulated extracellular dopamine in the medial shell of the nucleus accumbens, no change in electrically stimulated or amphetamine-induced dopamine release, and no change in dopamine tissue content. CONCLUSIONS: These results support the view that GLT-1 expression in neurons is required for amphetamine-induced behavioral activation, and suggest that this phenotype is not produced through a change in dopamine uptake or release. Although GLT-1 is highly expressed in neurons in the CA3 region of the hippocampus, the tests used in this study were not able to detect a behavioral phenotype referable to hippocampal dysfunction.

Shaken Baby Syndrome: a review.

Shaken Baby Syndrome occurs in infants as a result of the brain pushing against the skull due to severe acceleration-deceleration forces. Symptoms of Shaken Baby Syndrome include subdural, subarachnoid, and retinal hemorrhages. MRI and ocular examinations are used to determine the extent of mental and visual damage and ß-amyloid precursor protein immunohistochemical staining is used to detect axonal injuries. Surgeries such as Subdural hemorrhage (SDH) evacuation surgery and the Burr hole craniotomy are used to treat Shaken Baby Syndrome; however, the prognosis is poor in many cases. Because of the severity of Shaken Baby Syndrome and its traumatic and sometimes fatal effects, it is important to educate new parents, nurses, and doctors on the syndrome in order to prevent incidents.