Predictors of U.S. Adults' Opinion Toward an R-Rating Policy for Movies With Cigarette Smoking.

Recently, multiple health organizations and advocacy groups have pushed for giving an R-rating for movies depicting tobacco imagery. This study examined several predictors of U.S. adults' opinion toward an R-rating policy for movies depicting cigarette smoking. We used data from the Health Information National Trends Survey (2020 cycle), for a nationally representative sample of 3,865 US adults (aged ≥ 18). The outcome variable was opinion toward an R-rating policy (support, neutral, and oppose) for movies depicting cigarette smoking. A weighted adjusted multinomial logistic regression analysis with comparisons of support versus oppose, support versus neutral, and neutral versus oppose was performed. About 48.2% of respondents were supportive of, 31.1% were neutral toward, and 20.7% were opposed to an R-rating policy. Adults aged 50 to 64 years (adjusted odds ratio [aOR] = 2.28, p = .008) and ≥65 years (aOR = 4.54, p <.001) (vs. 18-34 years) were more likely to support the R-rating policy than oppose it. Non-Hispanic Black respondents (vs. non-Hispanic Whites) were 1.74 times more likely to support than oppose the policy (aOR = 1.74, p = .04), whereas adults with a household annual income of US$75,000 or more (vs. <$20,000) and those with moderate (vs. liberal) political viewpoints were more likely to be neutral than oppose the policy. Former and current e-cigarette users (vs. never users) were less likely to support than oppose the policy. Tailored messaging addressing the rationale behind R-rating policy should be directed towards communities based on age, race/ethnicity, household income, e-cigarette usage, and political ideologies.

Predictors of Adolescents' Transition Through the Stages of Change for Quitting E-Cigarettes: Findings From the Population Assessment of Tobacco and Health Study.

PURPOSE: To identify predictive factors associated with US adolescents' transition through the stages of change for potentially quitting e-cigarettes using the Trans-theoretical model of behavior change. DESIGN: Prospective cohort study. SETTING: United States. SUBJECTS: We utilized data from adolescents (12-17 years) in Wave 3 of the Population Assessment of Tobacco and Health study who used e-cigarettes exclusively over the past 30 days (n = 177) and were followed up with in Wave 4. MEASURES: Outcome variables were 3 transition categories: those who remained stagnant, those who progressed, and those who regressed in their stage of quitting e-cigarettes. Predictor variables were socio-demographics, e-cigarette harm perception, e-cigarette use at home or by important people, social norms, e-cigarette and anti-tobacco advertisements, and e-cigarette health warnings. ANALYSIS: Weighted-adjusted multinomial regression analysis was performed to determine the association between predictor and outcome variables. RESULTS: From Wave 3 to Wave 4, 19% of adolescents remained stagnant; 73.3% progressed; and 7.7% regressed. Adolescents were less likely to progress in their stage of change if they perceived nicotine in e-cigarettes to be "not at all/slightly harmful" (AOR = .26 [95% CI: .25, .27], P < .001); reported important people's use of e-cigarettes (AOR = .18 [95% CI: .05, .65, P = .009); and "rarely" noticed e-cigarette health warnings (AOR = .28 [95% CI: .08, .98, P = .054). CONCLUSION: Intervention efforts must target specific predictive factors that may help adolescents quit e-cigarettes.

Disparities in E-Cigarette Harm and Addiction Perceptions Among Adolescents in the United States: a Systematic Review of the Literature.

BACKGROUND: Health disparities associated with e-cigarette use are increasingly apparent among US adolescents. Perceptions of e-cigarette harm and addiction play an important role in understanding adolescents' e-cigarette use behavior. The objective of this systematic review is to examine racial/ethnic and socio-economic disparities in e-cigarette harm and addiction perceptions among US adolescents. METHODS: We searched five databases to identify cross-sectional or longitudinal studies that focused on adolescents (≤ 18 years of age) who were ever, current, or never e-cigarettes users; we then examined how race/ethnicity and/or socio-economic status (SES) impacted e-cigarette harm and/or addiction perceptions. Two co-authors independently identified relevant studies, extracted data, and assessed the risk of bias. RESULTS: Adhering to PRISMA guidelines, eight of 226 identified studies met the inclusion criteria. These eight studies examined either perceptions regarding absolute e-cigarette harm and/or addiction (i.e., assessing perception of only e-cigarette) or relative e-cigarette harm and/or addiction (i.e., comparative perceptions to traditional cigarettes) by race and ethnicity. Two of the eight studies assessed absolute harm and/or addiction perceptions of e-cigarettes by SES. Our results indicate that, compared to all other racial/ethnic groups, relative e-cigarette harm and addiction perceptions were lower among Non-Hispanic White adolescents; however, absolute e-cigarette harm perception was higher among these groups. No clear patterns of racial/ethnic differences in absolute e-cigarette addiction perceptions and SES differences in absolute e-cigarette harm perceptions were reported. CONCLUSION: More research is needed to explicitly assess perceptions of e-cigarette harm and addiction among US adolescents by race/ethnicity and SES to develop subgroup appropriate public health messaging.

Association Between Adverse Childhood Experiences and Opioid Use-Related Behaviors: A Systematic Review.

As opioid use-related behaviors continue at epidemic proportions, identifying the root causes of these behaviors is critical. Adverse childhood experiences (ACEs) are shown to be an important predictor of opioid initiation, opioid dependence, and lifetime opioid overdose. The purpose of this systematic review is to examine the association between ACEs and opioid use-related behaviors later in life and to discuss implications for policy, practice, and research regarding ACEs and opioids. Five databases (PubMed, PsycINFO, CINAHL, Medline, and Scopus) were used to identify studies investigating the association between ACEs and opioid use-related behaviors. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 20 studies out of the initial 428 met the inclusion criteria for this review. Among the included 20 studies, 15 focused on the relationship between ACEs and lifetime opioid use-related behaviors, and five focused on current opioid use-related behaviors. All studies found statistical associations between ACEs and lifetime or current opioid use-related behaviors. Five studies found a significant gradient effect; that is, as the number of ACEs increased, the risk of opioid use-related behaviors also increased. A significant dose-response relationship exists between ACEs and opioid use-related behaviors. Hence, it is essential for clinicians to screen for ACEs before prescribing opioid medications, for opioid treatment to incorporate trauma-informed methods, and for messaging around opioid use interventions to include information about ACEs. The current review points to a critical need to implement standardized ACE screening instruments in clinical and research settings.

Driving under the influence of substances and motor vehicle fatalities among older adults in the United States.

OBJECTIVE: This study examines contribution of substance use (including alcohol, cannabinoids, stimulants, narcotics, depressants, and hallucinogens) on the probability of drivers being at-fault for a crash on U.S. public roads, with specific emphasis on older adult drivers. METHODS: Data from the National Highway Traffic Safety Administration's Fatality Analysis Reporting System (FARS) for the years 2010-2018 were employed for 87,060 drivers (43,530 two-vehicle crash pairs) involved in two moving vehicle crashes. The quasi-induced exposure (QIE) method was used to compute the relative crash involvement ratios (CIRs) for each relevant substance and illicit drug. Mixed-effect generalized linear regression models were fit to examine the effect of substance use on the probability of a driver being at-fault for a crash. RESULTS: There were 75.51% males and 73.88% Non-Hispanic Whites in our sample. The CIR for those aged 70-79 years was 1.17, and more than double (2.56) for the ≥80 years old drivers, while being relatively low among drivers of ages 20 to 69. Substance use, in general, disproportionately increased the probability of being at-fault during a crash, regardless of driver's age. Though older drivers are less likely than other age groups to report substance use, presence of substances among older drivers increased the probability of their being at-fault two to four times during a crash across almost all substances. The regression models, after adjusting for driver's sex, road grade, weather, light conditions, distraction, and speeding at time of crash, revealed that older drug-impaired drivers were twice as likely to be at fault in a fatal crash (aOR = 1.947; 95% CI = 1.821, 2.082; <0.0001) compared to their middle-aged counterparts. Similarly, most substance use categories were responsible for the probabilities of higher CIRs among the drivers. CONCLUSION: These findings necessitate continued efforts to bring awareness to the deadly consequences of "drugged driving," especially among older adult drivers.

Efficacy of Extended-Release Injectable Naltrexone on Alcohol Use Disorder Treatment: A Systematic Review.

Alcohol use disorder (AUD) is a serious public health problem. Over 3.3 million people worldwide die each year due to alcohol-related causes, which is almost 5.3% of all deaths. This systematic review examines the effectiveness of injectable naltrexone treatment for people with AUD based on randomized clinical trial studies conducted between January 2004 and December 2019. Following PRISMA-P, this review searched PubMed, PsycINFO, CINAHL, Cochrane Library, and Web of Science for relevant studies. The inclusion criteria were AUD treatment, injectable naltrexone, and randomized clinical trials. Only articles written in English, involving human participants, and published in peer-reviewed journals were considered for this review. A total of 11 studies met the inclusion criteria. Ten out of the 11 studies assessed the impact of injectable naltrexone in a 3- to 6-month follow-up period, with one study having a year follow-up. This systematic review indicates that overall, injectable naltrexone therapy produced positive AUD treatment outcomes, including reduced mean time to first drinking day and/or heavy drinking day, decreased number of drinking and/or heavy drinking days, and increased abstinence, frequently at a statistically significant level in the larger studies. However, in all studies, less than half of the participants were completely abstinent after receiving injectable naltrexone. Injectable naltrexone treatment along with psychosocial therapy holds promise for addressing AUD.

Factors Associated with E-Cigarette Quit Intention Among Adolescents in the United States.

Background: Given increasing use of e-cigarettes among adolescents in the United States and its potential for nicotine addiction, encouraging adolescents to quit using these products has become a public health priority. This study examined factors at various socio-ecological levels associated with e-cigarette quit intention (pre-contemplation, contemplation, or preparation) using the Stages of Change of the Trans-theoretical Model among the U.S. adolescents. Methods: We used cross-sectional data from the past 30-day adolescent exclusive e-cigarette users participating in Wave 4 of the Population Assessment of Tobacco and Health study (n = 349). Weighted adjusted multinomial logistic regression models were used to analyze the data. Results: Compared to pre-contemplators and contemplators, preparators were more likely to believe that nicotine in e-cigarettes was "very/extremely harmful" (vs. "not at all harmful") to health (p < 0.001) and people cause a "lot of harm" (vs. "no harm") to themselves when they use e-cigarettes (p < 0.001). In comparison to pre-contemplators, contemplators and preparators were more likely to report that their parents/guardians talked with them about not using e-cigarettes than those whose parents/guardians did not talk with them (p < 0.001). Additionally, contemplators and preparators were also more likely to report that they "often/very often" (vs. never) noticed health warnings on e-cigarette packages (p < 0.001). Conclusion: Our findings suggest that harm perception, influence of family, and e-cigarette health warnings are some of the important factors associated with the stages of change for intention to quit among adolescent e-cigarette users. This study will help public health practitioners and researchers design multi-level e-cigarette cessation interventions for adolescents.

Factors Associated With E-Cigarette Quitting Behavior Among Adolescents in the United States: A Prospective Observational Study.

PURPOSE: This prospective observational study examined the association of socioecological factors with quitting behavior among US adolescents who exclusively use electronic cigarettes (e-cigarettes). METHODS: We used data from past 30-day adolescent exclusive e-cigarette users (n = 243) participating in Wave 3 of the Population Assessment of Tobacco and Health study, who were then followed-up with approximately 12 months later for Wave 4. Weighted unadjusted and adjusted multivariate logistic regression models and structural equation modeling were performed to analyze the data. RESULTS: Adolescents were significantly less likely to quit e-cigarettes if they perceived that nicotine in e-cigarettes was "slightly/somewhat harmful" to health (adjusted odds ratio [aOR] = 0.38; 95% confidence interval [CI]: 0.16-0.90, p = .02). Similarly, adolescents who reported that someone else in their home owned an e-cigarette (aOR = 0.43 [95% CI: 0.19-0.94], p = .03) or important people in their life used e-cigarettes (aOR = 0.45 [95% CI: 0.21-0.95], p = .03) were significantly less likely to quit e-cigarettes. The structural equation modeling showed a direct significant relationship of individual-level (b = 0.206, p = .02) and interpersonal-level factors (b = 0.170, p = .04) with e-cigarette quitting behavior. DISCUSSION: Our findings suggest that individual-level (harm perception) and interpersonal-level (e-cigarette use at home and by important people) factors may play a significant role in e-cigarette quitting behavior among US adolescents.

"Waterpipe Is Like a Wife": Qualitative Assessment of Perspectives on Waterpipe Smoking Dependence.

Background: Waterpipe (WP) smoking has become a global public health problem in recent decades and growing evidence indicates that it can cause nicotine dependence. Most evidence on WP dependence to date has been derived from survey- or laboratory-based studies. This study employed qualitative methods to explore WP users' perceptions of dependence in Aleppo, Syria. Methods: A total of 15 focus groups were conducted with 64 adult WP smokers (51 males and 13 females) using a semi-structured interview. All focus group discussions were audiotaped, transcribed, and coded using directed content analysis. Findings: Several WP dependence features were consistent with those commonly reported by cigarette smokers. These included positively reinforced features, such as smoking's association with social gatherings and cultural connectedness, and negatively reinforced features including relief of withdrawal symptoms, stress, and boredom. Although interest in quitting was low, many users perceived quitting WP to be difficult and an indicator of loss of control over smoking, a common marker of dependence. Several observed dependence features were specific to WP, including transitioning from social smoking to smoking alone, and adapting one's behavior to the considerable effort normally required to engage in WP smoking despite inconvenience or cost, and often at the expense of other reinforcers such as social interaction. Conclusion: The general and specific features of WP dependence need to be considered in developing instruments to measure WP dependence, in clinical assessment of WP dependence, and in developing cessation programs.

Effectiveness of Interventions to Improve Oral Cancer Knowledge: a Systematic Review.

Oral cancer is prone to late-stage diagnosis, and subsequent low five-year survival rates. A small number of interventions or campaigns designed to enhance knowledge of risk factors and symptoms associated with oral cancer have been attempted in the UK, US, and some other countries. The purpose of this systematic review is to assess the effectiveness of interventions designed to improve oral cancer knowledge. We searched five databases to identify randomized controlled trials (RCTs) and non-randomized/quasi-experimental (NR/QE) studies targeting the general population or high-risk groups (tobacco users or alcohol consumers), aged ≥15 years, and reporting the outcomes of individual and/or community level interventions. Two co-authors independently identified relevant studies, extracted data, and assessed the risk of bias. Adhering to PRISMA guidelines, 27 (eight RCTs and 19 NR/QE studies) of the 551 studies identified from the five databases met the inclusion criteria. All RCTs and nine NR/QE studies used either printed materials, health education sessions, multimedia aids, or some combinations of these tools. The other ten NR/QE studies were community-based and used mass media campaigns to increase oral cancer awareness. Overall, the majority of studies significantly improved oral cancer knowledge; however, heterogeneity in study design and variation in measurement tools made it difficult to compare outcomes. Findings suggest that individual and/or community level interventions are generally effective in increasing knowledge of oral cancer risk factors, signs and symptoms, and/or its early diagnosis and prevention strategies among the general population or high-risk groups. However, the long-term benefits of these interventions are understudied.

Smoking Cessation among Pregnant and Postpartum Women from Low-Income Groups in the United States.

INTRODUCTION: Pregnancy creates a unique window of opportunity for smoking cessation. However, pregnant women from underserved groups can face personal, social, and environmental challenges that impede quitting. This study draws upon the socioecological framework to explore perspectives on smoking cessation among pregnant and postpartum women from low-income groups in the mid-South of the United States. METHODS: Semistructured interviews were conducted with 60 women who were pregnant or postpartum. Data were analyzed in Dedoose qualitative software using the directed content analysis approach. RESULTS: Findings reveal that at the individual level, motivations for smoking cessation included the fact of being pregnant, risks associated with the infant's health, and desire to breastfeed. However, some pregnant women perceived that slowing down on smoking during pregnancy was adequate to prevent harm to their fetuses. Individual-level factors that made smoking cessation difficult included nicotine addiction and habit, boredom, stressful life circumstances, fear of weight gain, and perceived lack of willpower. At the interpersonal level, living in a smoke-free environment where loved ones do not smoke and emotional and practical support from social network members including partners and family members were thought to facilitate smoking cessation. At the organizational level, access to nicotine replacement therapies and counseling aided in their abilities to quit smoking. At the policy level, pregnant women viewed increase in cigarette prices, warning labels on the cigarette pack, and the potential for a ban on cigarette sales as having some effect in helping them quit smoking. DISCUSSION: This study offers theoretical insights into factors that function as barriers or facilitators of smoking cessation among pregnant and postpartum women from low-income groups in the United States. Designing multilevel smoking cessation interventions while considering the interplay of individual, interpersonal, organizational, and policy level factors may lead to better cessation outcomes.

Perception and intention of using less harmful and less addictive hypothetical modified risk tobacco products among never tobacco users in the united states.

AIMS: There is limited research focusing on how never tobacco users respond to claims associated with modified risk tobacco products (MRTPs). The purpose of the present study is twofold: (1) to identify how never tobacco users perceive hypothetical modified risk tobacco product (MRTP) claims; and (2) to assess whether these perceptions impact their intentions of using MRTPs described as "less harmful" and "less addictive." METHOD: The present study draws upon a nationally representative dataset of US adults aged ≥ 18 years (n = 850) from a cross-sectional survey (HINTS-FDA, Cycle 2, 2017). Weighted unadjusted and adjusted logistic regression analyses were performed to analyze the data. RESULTS: Participants who perceived tobacco products labeled as having "no additives" to be less harmful were close to three times more likely to report intentions of using "less harmful" (Adjusted OR = 2.93 [95% CI: 1.12-7.65]) and "less addictive" (Adjusted OR = 2.72 [95% CI: 1.03-7.21]) tobacco products than those who perceived them to be more/equally harmful. Participants who believed that tobacco products could be manufactured without some chemicals were over five and six times more likely to report intentions of using "less harmful" (Adjusted OR = 5.53 [95% CI: 1.59-19.25]) and "less addictive" (Adjusted OR = 6.60 [95% CI: 2.65-16.46]) tobacco products than those who were unlikely to believe it. CONCLUSIONS: Our findings have implications for FDA's regulation of MRTPs and provides insights regarding how the marketing of authorized MRTPs could impact population health in the future.

Prevalence of Cardiovascular Disease Risk Factors by Key Demographic Variables Among Mid-South Church Leaders from 2012 to 2017.

Cardiovascular disease (CVD) risk factors were examined among church leaders (n = 2309) who attended Mid-South United Methodist Church annual meetings between 2012 and 2017 using repeated cross-sectional data. There was a significant increase in body mass index (BMI) (b = 0.24, p = 0.001) and significant decreases in blood pressure (systolic: b = - 1.08, p < 0.001; diastolic: b = - 0.41, p = 0.002), total cholesterol (b = - 1.76, p = 0.001), and blood sugar (b = - 1.78, p = 0.001) over time. Compared to Whites, a significant increase was seen in BMI (b = 1.14, p = 0.008) among participants who self-identified as "Other," and a significant increase was seen in blood pressure (systolic: b = 1.36, p = 0.010; diastolic: b = 1.01, p = 0.004) among African Americans over time. Results indicate BMI and blood pressure are important CVD risk factors to monitor and address among church leaders, especially among race/ethnic minority church leaders.

Online Narratives of Methamphetamine Use and Risky Sexual Behavior: Can Shame-Free Guilt Aid in Recovery?

Methamphetamine (meth) use is a recurring public health challenge in the U.S. In 2016, approximately 1.6 million Americans reported using meth. Meth use is associated with a number of adverse outcomes, including those associated with users' sexual health. In particular, meth use is linked to an increased risk for sexually transmitted infections and unplanned pregnancies. While studies have examined associations between substance use of various types-including meth use, and shame and guilt-few studies have examined relationships among substance use, sexual risk behaviors, and shame and guilt. No qualitative studies, to our knowledge, have studied all three of these phenomena in a sample of meth users. The present qualitative study explored the sexual risk behaviors and associated feelings of shame and guilt in relation to meth use. It draws from anonymous letters and stories (N = 202) posted to an online discussion forum by meth users and their family members. A grounded theory analysis of these narratives identified four primary themes pertaining to meth use and sexual behaviors: (1) feeling heightened sexual arousal and stimulation on meth, (2) experiencing sexual dissatisfaction on meth, (3) responding to sexual arousal and dissatisfaction, and (4) feeling ashamed and/or guilty. Ultimately, the present findings indicate that feelings of shame and guilt may arise more from the consequences of sexual risk behaviors stemming from meth use rather than meth use itself. The emotional toll of meth-induced sexual risk behaviors, particularly shame and guilt over the loss of meaningful relationships and self-respect due to multiple sexual partners, may provide an important opportunity for interventionists.

Navigation in a Space With Moving Objects: Rats Can Avoid Specific Locations Defined With Respect to a Moving Robot.

Animals can organize their behavior with respect to other moving animals or objects; when hunting or escaping a predator, when migrating in groups or during various social interactions. In rats, we aimed to characterize spatial behaviors relative to moving objects and to explore the cognitive mechanisms controlling these behaviors. Three groups of animals were trained to avoid a mild foot-shock delivered in one of three positions: either in front, on the left side, or on the right side of a moving robot. We showed the rats can recognize and avoid these specific areas. The avoidance behavior specific for the left or right side of the robot demonstrated animals not only react to "simple" stimuli such as increasing noise level or growing retinal image of an approaching object, but they process their spatial position relative to the object. Using an all-white robot without prominent visual patterns that would distinguish its different sides, we showed that the behavior does not depend on responses to prominent visual patterns, but that the rats can guide their navigation according to geometrical spatial relationship relative to the moving object. Rats' competence for navigation in space defined by a moving object resembles navigation abilities in stationary space. Recording of hippocampal single unit activity during rat's interaction with the robot proved feasibility of the task to uncover neuronal mechanism of this type of navigation.

Compositional and contextual factors associated with drug overdose deaths in the United States.

Background: In 2017, the US Department of Health and Human Services declared the Opioid epidemic a public health emergency. In the US, emergency rooms treat more than 1,000 people each day for drug overdose, and 115 of them die. This study examines compositional and contextual factors associated with drug overdose deaths rates in the US. Methods: Local spatial autocorrelation statistics were used to estimate hot spot areas to identify census tracts with high risk of drug overdose death. Logistic regressions investigated the relationship between drug overdose death rates and various compositional and contextual variables across census tracks. Results: The adjusted logistic model shows that compositional variables: depression (OR = 2.47 [2.37-2.58]), poor mental health (OR = 1.71 [1.63-1.79]), median age 1.41 (1.36-1.47) and the percentage of people with a high school diploma (OR = 1.30 [1.24-1.35]) were positively associated with the rate of drug overdose deaths. On the other hand, contextual variables: the percentage having health insurance (OR = 0.66 [0.64-0.69]), the Theil's H index (OR = 0.69 [0.66-0.71]), population density (OR = 0.80 [0.77-0.84]), poverty (OR = 0.90 [0.86-0.95]), and median household income (OR = 0.91[0.86-0.96]) were negatively associated with drug overdose deaths. Discussion: The analysis reveals a consistently strong association between compositional mental health factors and census tract-level death rates from drug overdose.

Impairment of neural coordination in hippocampal neuronal ensembles after a psychotomimetic dose of dizocilpine.

The discoordination hypothesis of schizophrenia posits discoordination of neural activity as the central mechanism that underlies some psychotic symptoms (including 'hallmark' cognitive symptoms) of schizophrenia. To test this proposition, we studied the activity of hippocampal neurons in urethane anesthetized Long Evans rats after 0.15mg/kg dizocilpine (MK-801), an N-Methyl-d-aspartate (NMDA) glutamate receptor antagonist, which can cause psychotic symptoms in humans and cognitive control impairments in animals. We observed that MK-801 altered the temporal coordination, but not rate, of neuronal firing. Coactivation between neurons increased, driven primarily by increased coincident firing of cell pairs that did not originally fire together before MK-801 injection. Increased pairwise coactivation manifested as disorganized discharge on the level of neuronal ensembles, which in turn could lead to disorganization in information processing. Disorganization of neuronal activity after a psychotomimetic dose of MK-801 supports the discoordination hypothesis of psychosis.

Transient inactivation of the anterior cingulate cortex in rats disrupts avoidance of a dynamic object.

Although animals often learn and monitor the spatial properties of relevant moving objects such as conspecifics and predators to properly organize their own spatial behavior, the underlying brain substrate has received little attention and hence remains elusive. Because the anterior cingulate cortex (ACC) participates in conflict monitoring and effort-based decision making, and ACC neurons respond to objects in the environment, it may also play a role in the monitoring of moving cues and exerting the appropriate spatial response. We used a robot avoidance task in which a rat had to maintain at least a 25cm distance from a small programmable robot to avoid a foot shock. In successive sessions, we trained ten Long Evans male rats to avoid a fast-moving robot (4cm/s), a stationary robot, and a slow-moving robot (1cm/s). In each condition, the ACC was transiently inactivated by bilateral injections of muscimol in the penultimate session and a control saline injection was given in the last session. Compared to the corresponding saline session, ACC-inactivated rats received more shocks when tested in the fast-moving condition, but not in the stationary or slow robot conditions. Furthermore, ACC-inactivated rats less frequently responded to an approaching robot with appropriate escape responses although their response to shock stimuli remained preserved. Since we observed no effect on slow or stationary robot avoidance, we conclude that the ACC may exert cognitive efforts for monitoring dynamic updating of the position of an object, a role complementary to the dorsal hippocampus.

Growth and refinement of excitatory synapses in the human auditory cortex.

We had earlier demonstrated a neurofilament-rich plexus of axons in the presumptive human auditory cortex during fetal development which became adult-like during infancy. To elucidate the origin of these axons, we studied the expression of the vesicular glutamate transporters (VGLUT) 1 and 2 in the human auditory cortex at different stages of development. While VGLUT-1 expression predominates in intrinsic and cortico-cortical synapses, VGLUT-2 expression predominates in thalamocortical synapses. Levels of VGLUT-2 mRNA were higher in the auditory cortex before birth compared to postnatal development. In contrast, levels of VGLUT-1 mRNA were low before birth and increased during postnatal development to peak during childhood and then began to decrease in adolescence. Both VGLUT-1 and VGLUT-2 proteins were present in the human auditory cortex as early as 15GW. Further, immunohistochemistry revealed that the supra- and infragranular layers were more immunoreactive for VGLUT-1 compared to that in Layer IV at 34GW and this pattern was maintained until adulthood. As for VGLUT-1 mRNA, VGLUT-1 synapses increased in density between prenatal development and childhood in the human auditory cortex after which they appeared to undergo attrition or pruning. The adult pattern of VGLUT-2 immunoreactivity (a dense band of VGLUT-2-positive terminals in Layer IV) also began to appear in the presumptive Heschl's gyrus at 34GW. The density of VGLUT-2-positive puncta in Layer IV increased between prenatal development and adolescence, followed by a decrease in adulthood, suggesting that thalamic axons which innervate the human auditory cortex undergo pruning comparatively late in development.