Effects of chronic variable stress and antidepressant drugs on behavioral inactivity during an uncontrollable stress: interaction between both treatments.

Rats submitted to a chronic variable stress regime exhibited more inactivity during inescapable shock as compared with unstressed rats. Besides, chronic treatments with desipramine, imipramine, clomipramine, or phenelzine reduce the amount of inactivity exhibited during this aversive experience. Furthermore, the combination of both chronic treatments--stress and antidepressants--resulted in a potentiation of the antidepressant effect alone. This higher antidepressant efficacy may result from the interaction of the neural mechanisms triggered by chronic stress exposure and antidepressant drugs.     

Differential ethanol olfactory experiences affect ethanol ingestion in preweanlings but not in older rats

Preweanling (21 days old) and adult (60-80 days old) rats were exposed to ethanol odor either paired with the early stages of apomorphine-induced toxicosis, paired with the recovery from toxicosis, or unpaired with the induction of distress. Twenty four hours later, ethanol preferences were measured in a spatial olfactory test (ethanol vs lemon odor) or a drinking test (5.6% v/v ethanol vs 0.25% w/v citric acid solutions). During the olfactory test both young and adult rats expressed substantial ethanol odor aversions when previously exposed to this odor paired with toxicosis. However, changes in ethanol intake became apparent only in preweanling subjects. Preweanlings which received the ethanol odor paired with illness drank significantly less of the ethanol solution relative to controls, while subjects experiencing the odor paired with recovery from distress significantly increased their consumption of the ethanol solution. These prior aversive and appetitive olfactory experiences had no effect upon ethanol intake in adult rats. These results implicate both an ontogenetic and a sensorial factor in the regulation of ethanol intake.     

Weanlings' transfer of conditioned ethanol aversion from olfaction to ingestion depends on the unconditioned stimulus

Weanling (21-day-old) rats were exposed to an alcohol odor paired with either an interoceptive (apomorphine-induced illness) or exteroceptive (footshock-induced distress) reinforcer. Twenty-four hours later, ethanol preferences were measured in a locational olfactory test (ethanol vs lemon odor) or an ingestion test (5.6% v/v ethanol vs 0.25% v/v citric acid solution). Weanling rats expressed substantial olfactory aversions, independent of the reinforcer employed in conditioning. During the drinking test, however, only rats that had experienced the ethanol odor paired with internal malaise showed a significant reduction in the intake of the ethanol solution when compared to unpaired controls. Furthermore, rats that had experienced the ethanol odor paired with external distress drank significantly more of the ethanol solution than their controls. These results provide further evidence that olfactory experiences with ethanol can lead to changes in ethanol ingestion, and indicate that the nature of the unconditioned stimulus is critical in establishing the ingestive effect.     

“You're overreacting!”: The ambiguity of Asian American microaggressions delegitimizes collective action

Asian Americans are lauded as the model minority who are intelligent and industrious. Simultaneously, they are deemed as perpetual foreigners. The current research examines how racial microaggressions expressed by a White American source toward an Asian American target affect perceptions of the perpetrator and target. White Americans and Asian Americans read about an interaction between two college students, where the racial microaggression made was either an ambiguous expression of the model minority myth (MMM; all studies), an ambiguous perpetual foreigner stereotype (all studies), an unambiguous MMM (all studies), or no racial bias (Studies 2 and 3). Findings indicate that both Whites and Asian Americans respond differently—when exposed to the aforementioned conditions—regarding perceived racism of the White perpetrator and appropriateness of response by the Asian American target; however, they respond similarly regarding perceived legitimacy of collective action by the target. Nevertheless, Whites and Asian Americans deemed the ambiguous microaggression against the target as a model minority not racist relative to unambiguous MMM. Our findings show that ambiguous forms of bias toward Asian Americans go “under the radar” of both Whites and Asian Americans as being racist and contribute to the maintenance of the racial status quo.     

Ethanol-mediated taste aversions and state-dependency in preweanling (16-day-old) rats

Requirements for conditioning of an ethanol-mediated taste aversion in 16-day-old rat pups were examined. Experiment 1 demonstrated that preweanling rats are capable of acquiring, in two trials, an aversion to a 15% sucrose solution when followed by intragastric intubation of a 1.2 g/kg dose of 17% v/v ethanol, but not when followed by a 0.4 g/kg dose. Comparison was with control animals given sucrose followed by an equivalent volume isocaloric Half and Half. When the 0.4 g/kg dose of ethanol preceded sucrose presentation by 30 min (Experiment 2), the aversion was learned, suggesting that the effective delay between the sucrose and the critical consequences of the ethanol had been too long with the former procedure. Expression of the sucrose aversion required, however, the reinstatement of the context of intoxication--state-dependent retention. Finally, the results of Experiment 3B indicated that, in addition to the association between the sucrose and the aversive consequences of alcohol intoxication, the orosensory cues resulting from alcohol's direct elimination, via such processes as respiration and salivation, became associated with the appetitive properties of the sucrose. This was evidenced by a conditioned increase in preference for ethanol odor. Possible age-related differences in the ability to associate stimuli with alcohol's unconditioned consequences, and in state dependency are discussed.     

Electrolytic lesions of the pedunculopontine nucleus disrupt concurrent learned aversion induced by NaCl

Bilateral electrolytic lesions in the pedunculopontine nucleus (PPN) impair acquisition of short-term, or concurrent, Taste Aversion Learning (TAL) in rats. This type of TAL is characterized by the daily presentation of two different flavor stimuli at the same time, one associated with simultaneous intragastric administration of an aversive product (hypertonic NaCl) and the other with physiological saline. Sham-lesioned control animals learn this taste discrimination task, but both lesioned animals and control animals learn a long-term, or delayed, TAL task in which each gustatory stimulus is presented individually every other day and the intragastric products, LiCl (0.15 M) and physiological saline, are administered after a 15-min delay. These results are analyzed in the context of the cerebellar circuits involved in learning and in relation to the two TAL modalities described above.     

Peer Rejection and Friendships in Children with Attention-Deficit/Hyperactivity Disorder: Contributions to Long-Term Outcomes

Even after evidence-based treatment, Attention-Deficit/Hyperactivity Disorder (ADHD) is associated with poor long-term outcomes. These outcomes may be partly explained by difficulties in peer functioning, which are common among children with ADHD and which do not respond optimally to standard ADHD treatments. We examined whether peer rejection and lack of dyadic friendships experienced by children with ADHD after treatment contribute to long-term emotional and behavioral problems and global impairment, and whether having a reciprocal friend buffers the negative effects of peer rejection. Children with Combined type ADHD (N?=?300) enrolled in the Multimodal Treatment Study of Children with ADHD (MTA) were followed for 8 years. Peer rejection and dyadic friendships were measured with sociometric assessments after the active treatment period (14 or 24 months after baseline; M ages 9.7 and 10.5 years, respectively). Outcomes included delinquency, depression, anxiety, substance use, and general impairment at 6 and 8 years after baseline (Mean ages 14.9 and 16.8 years, respectively). With inclusion of key covariates, including demographics, symptoms of ADHD, ODD, and CD, and level of the outcome variable at 24 months, peer rejection predicted cigarette smoking, delinquency, anxiety, and global impairment at 6 years and global impairment at 8 years after baseline. Having a reciprocal friend was not, however, uniquely predictive of any outcomes and did not reduce the negative effects of peer rejection. Evaluating and addressing peer rejection in treatment planning may be necessary to improve long-term outcomes in children with ADHD.     

Is an optimistic memory less easily influenced by negative than by positive emotions?

This work examines whether a positive personality trait, such as optimism, can reduce bias in differential words recalled after inducing a certain emotion. After showing a list of words with various emotional valences to a group of 59 subjects, a specific emotional state was induced. Subsequently, the subjects were asked to recall the list of words. The results obtained indicated that less optimistic subjects had a tendency to recall and recognize a greater number of negative words when in a negative emotional condition. Statistical significance was reached in the female group's negative word recognition when experiencing negative emotion.     

Childhood Trauma, Adult Sexual Assault, and Adult Gender Expression among Lesbian and Bisexual Women

Several studies have demonstrated that lesbian and bisexual women are more likely than heterosexual women to report childhood abuse and adult sexual assault. It is unknown, however, which sexual minority women are most likely to experience such abuse. We recruited adult sexual minority women living in the US through electronic fliers sent to listservs and website groups inviting them to complete an online survey (N?=?1,243). We examined differences in both childhood abuse and adult sexual assault by women’s current gender identity (i.e., butch, femme, androgynous, or other) and a continuous measure of gender expression (from butch/masculine to femme/feminine), adjusting for sexual orientation identity, age, education, and income. Results indicated that a more butch/masculine current self-assessment of gender expression, but not gender identity, was associated with more overall reported childhood trauma. Although one aspect of gender expression, a more butch/masculine gender role, was associated with adult sexual assault, feminine appearance and a femme gender identity also significantly predicted adult sexual assault. These findings highlight the significance of gender identity and expression in identifying women at greater risk for various abuse experiences.     

The Delinquency Outcomes of Boys with ADHD with and Without Comorbidity

This study examined the association between childhood ADHD and juvenile delinquency by examining data from the Pittsburgh ADHD Longitudinal Study (PALS), a follow-up study of individuals diagnosed with ADHD in childhood (ages 5–12) and recontacted in adolescence and young adulthood for yearly follow-up (age at first follow-up interview M = 17.26, SD = 3.17). Participants were 288 males with childhood ADHD and 209 demographically similar males without ADHD who were recruited into the follow-up study. Delinquency information gathered yearly during the second through eighth follow-up provided a comprehensive history of juvenile delinquency for all participants. Four childhood diagnostic groups [ADHD-only (N = 47), ADHD + ODD (N = 135), ADHD + CD (N = 106), and comparison (N = 209)] were used to examine group differences on delinquency outcomes. Analyses were conducted across three dimensions of delinquency (i.e., severity, age of initiation, and variety). Individuals with childhood ADHD + CD displayed significantly worse delinquency outcomes than the other three groups, across almost all indices of offending. When compared to comparison participants, boys with ADHD-only and ADHD + ODD in childhood displayed earlier ages of delinquency initiation, a greater variety of offending, and higher prevalence of severe delinquency. These findings suggest that although childhood ADHD + CD creates the greatest risk for delinquency, boys with ADHD-only and ADHD + ODD also appear at a higher risk for later offending. The patterns of offending that emerged from the PALS are discussed in the context of the relationship between ADHD, comorbidity, and delinquency.