Environmental enrichment attenuates nicotine behavioral sensitization in male and female rats

Environmental enrichment decreases nicotine reactivity in male rats, but these effects have not been examined in females. This research was conducted to examine the effects of enrichment on nicotine behavioral sensitization (i.e., nicotine reactivity) in male and female rats. One hundred forty-four Sprague-Dawley rats (72 male, 72 female) were raised in isolation, social enrichment (groups of three rats [SE]), or combined physical enrichment and social enrichment (groups of three rats with novel toys [PESE]) housing conditions. As adults, they received daily subcutaneous injections of saline or nicotine (0.1, 0.5, or 1.0 mg/kg) for 12 days; locomotor activity was measured on drug days 1, 5, 9, and 12. Before drug administration, PESE and SE decreased activity in males; only PESE decreased activity in females, F(2, 120) = 6.51, p < .01. In the drug phase, nicotine behavioral sensitization occurred, F(8.46, 341.04) = 20.71, p < .001, and was greater in females than males, F(8.340, 319.715) = 2.072, p < .05. Enrichment decreased nicotine behavioral sensitization in both sexes, F(16.91, 341.04) = 2.48, p < .01. In conclusion, nicotine behavioral sensitization occurred in male and female rats and was attenuated by environmental enrichment. This research has implications for treatment and prevention strategies in humans. Programs that incorporate aspects of social and environmental stimulation may have enhanced effectiveness in preventing and reducing cigarette smoking and may have implications for relapse prevention.

Interpersonal problem areas and alexithymia in adolescent girls with loss of control eating

This study investigated the links among interpersonal problem areas, depression, and alexithymia in adolescent girls at high risk for excessive weight gain and binge eating disorder. Participants were 56 girls (Mage = 14.30, SD = 1.56; 53% non-Hispanic White) with a body mass index (BMI, kg/m(2)) between the 75th and 97th percentiles (MBMI z = 1.57, SD = 0.32). By design, all participants reported loss of control eating patterns in the past month. Adolescents were individually interviewed prior to participating in a group interpersonal psychotherapy obesity and eating disorder prevention program, termed IPT for the prevention of excessive weight gain (IPT-WG). Participants' interpersonal problem areas were coded by trained raters. Participants also completed questionnaires assessing depression and alexithymia. Primary interpersonal problem areas were categorized as interpersonal deficits [as defined in the eating disorders (ED) literature] (n = 29), role disputes (n = 22), or role transitions (n = 5). Girls with interpersonal deficits-ED had greater depressive symptoms and alexithymia than girls with role disputes (p's ≤ 0.01). However, girls with role transitions did not differ from girls with interpersonal deficits-ED or role disputes. Interpersonal problem area had an indirect association with depression via alexithymia; interpersonal deficits-ED were related to greater alexithymia, which in turn, was related to greater depressive symptoms (p = 0.01). Among girls at risk for excess weight gain and eating disorders, those with interpersonal deficits-ED appear to have greater distress as compared to girls with role disputes or role transitions. Future research is required to elucidate the impact of interpersonal problem areas on psychotherapy outcomes.

Systematic review of prenatal cocaine exposure and adolescent development

BACKGROUND AND OBJECTIVE

Previous research found that prenatal cocaine exposure (PCE) may increase children's vulnerability to behavior and cognition problems. Maturational changes in brain and social development make adolescence an ideal time to reexamine associations. The objective was to conduct a systematic review of published studies examining associations between PCE and adolescent development (behavior, cognition/school outcomes, physiologic responses, and brain morphology/functioning).

METHODS

Articles were obtained from PubMed, PsycInfo, Web of Science, and CINAHL databases through July 2012 with search terms: prenatal drug, substance, or cocaine exposure; adolescence/adolescent; and in utero substance/drug exposure. Criteria for inclusion were nonexposed comparison group, human adolescents aged 11 to 19, peer-reviewed, English-language, and adolescent outcomes.

RESULTS

Twenty-seven studies representing 9 cohorts met the criteria. Four outcome categories were identified: behavior, cognition/school performance, brain structure/function, and physiologic responses. Eleven examined behavior; 7 found small but significant differences favoring nonexposed adolescents, with small effect sizes. Eight examined cognition/school performance; 6 reported significantly lower scores on language and memory tasks among adolescents with PCE, with varying effect sizes varied. Eight examined brain structure/function and reported morphologic differences with few functional differences. Three examined physiologic responses with discordant findings. Most studies controlled for other prenatal exposures, caregiving environment, and violence exposure; few examined mechanisms.

CONCLUSIONS

Consistent with findings among younger children, PCE increases the risk for small but significantly less favorable adolescent functioning. Although the clinical importance of differences is often unknown, the caregiving environment and violence exposure pose additional threats. Future research should investigate mechanisms linking PCE with adolescent functioning.

Behavioral effects of nicotine withdrawal differ by genetic strain in male and female adolescent rats

INTRODUCTION

Gender and ethnicity are powerful predictors of initiation and maintenance of cigarette smoking in adults but less is known about their role in smoking in adolescents. Consistent with human studies, rat models also reveal sex and strain differences in response to nicotine administration.

METHODS

This research examined nicotine withdrawal behaviors in 96 adolescent, male and female, Sprague Dawley (SD) and Long Evans (LE) rats. Rats received seven days continuous subcutaneous infusion of saline or 3.16 mg/kg nicotine via Alzet osmotic minipumps. Behavioral observations were made before, during, and after saline or nicotine administration. Occurrences of six specific behaviors were quantified: abnormal posture or movement, abnormal grooming, whole-body shakes, ptosis, empty-mouth chewing/teeth chattering, and diarrhea.

RESULTS

SD male and female rats that received nicotine displayed significantly more withdrawal behaviors 1 and 2 days after cessation of nicotine administration compared with rats that had received saline. LE male rats that received nicotine displayed significantly more withdrawal behaviors 1 day but not 2 days after cessation of nicotine administration compared with males that received saline. LE females showed no significant withdrawal behaviors after cessation of nicotine administration.

CONCLUSION

Results indicate that nicotine withdrawal in adolescent rats depends on sex and strain.

Behavioral effects of nicotine withdrawal in adult male and female rats

Nicotine withdrawal may differ between men and women but clinical reports are inconsistent. Two experiments were conducted to examine behavioral effects of nicotine withdrawal in male and female adult rats in dimly-lit and brightly-lit environments. Ninety-six Sprague-Dawley male and female rats received 7 days continuous subcutaneous infusion via ALZET osmotic minipumps filled with saline or 3.16 mg/kg/day nicotine hydrogen tartrate expressed as base. Behavioral observations were made before, during, and after drug administration. During observations, occurrences of empty-mouth-chewing, whole-body-shakes, abnormal grooming, abnormal posture/movement, diarrhea, ptosis, eyeblinks, and any other abnormal behaviors were counted. Cessation of nicotine administration upon pump removal caused a significant increase in withdrawal behaviors in males and females in both environments. In the dimly-lit environment, females showed more withdrawal behavior than males; there was no sex difference in the brightly-lit environment. Males that had received nicotine displayed more withdrawal behavior in the brightly-lit environment than in the dimly-lit environment, while females that had received nicotine displayed similar amounts of withdrawal behavior in both environments. Behavioral symptoms of withdrawal may be more affected by the environment in male rats than in female rats. These experiments are the first to compare nicotine withdrawal in adult male and female rats.

Interleukin-6-associated inflammatory processes in Alzheimer's disease: new therapeutic options

The cytokine interleukin-6 is consistently detected in the brains of Alzheimer's disease patients but not in the brains of nondemented elderly persons. Until recently it was unclear whether an interleukin-6-associated inflammatory mechanism is an early or late event in the pathological cascade of Alzheimer's disease. We investigated whether interleukin-6 could be detected in plaques of Alzheimer's disease patients prior to the onset of neuritic degeneration. We found interleukin-6 mostly in plaques where neuritic pathology has not yet developed. This indicates that the appearance of interleukin-6 may precede neuritic changes and is not just a consequence of neuritic degeneration. Therefore, one may hypothesize that activation of inflammatory mechanisms may cause neuritic degeneration in plaques. A suppression of interleukin-6 synthesis could, therefore, be of therapeutic value. Upon screening a number of substances, we found that a small number of nonsteroidal antiinflammatory drugs, including tenidap, were able to inhibit interleukin-6 synthesis in cultured human astrocytoma cells. These substances may be therapeutically useful in Alzheimer's disease and should be evaluated in clinical studies.

Mandibular hypoplasia secondary to perinatal trauma: report of case

A case of unilateral mandibular hypoplasia is presented. Considerations regarding a differential diagnosis of hemifacial microsomia or traumatically induced ankylosis of the temporomandibular joint are discussed. Although the described malformations might suggest a diagnosis of hemifacial microsomia, the history and clinical findings tend to support the conclusion that the asymmetry was caused by damage to the temporomandibular joint at an early age.