Sex and BDNF Val66Met polymorphism matter for exercise-induced increase in neurogenesis and cognition in middle-aged mice.

Females show greater benefits of exercise on cognition in both humans and rodents, which may be related to brain-derived neurotrophic factor (BDNF). A single nucleotide polymorphism (SNP), the Val66Met polymorphism, within the human BDNF gene, causes impaired activity-dependent secretion of neuronal BDNF and impairments to some forms of memory. We evaluated whether sex and BDNF genotype (Val66Met polymorphism (Met/Met) versus wild-type (Val/Val)) influenced the ability of voluntary running to enhance cognition and hippocampal neurogenesis in mice. Middle-aged C57BL/6J (13 months) mice were randomly assigned to either a control or an aerobic training (AT) group (running disk access). Mice were trained on the visual discrimination and reversal paradigm in a touchscreen-based technology to evaluate cognitive flexibility. BDNF Met/Met mice had fewer correct responses compared to BDNF Val/Val mice on both cognitive tasks. Female BDNF Val/Val mice showed greater cognitive flexibility compared to male mice regardless of AT. Despite running less than BDNF Val/Val mice, AT improved performance in both cognitive tasks in BDNF Met/Met mice. AT increased neurogenesis in the ventral hippocampus of BDNF Val/Val mice of both sexes and increased the proportion of mature type 3 doublecortin-expressing cells in the dorsal hippocampus of female mice only. Our results indicate AT improved cognitive performance in BDNF Met/Met mice and increased hippocampal neurogenesis in BDNF Val/Val mice in middle age. Furthermore, middle-aged female mice may benefit more from AT than males in terms of neuroplasticity, an effect that was influenced by the BDNF Val66Met polymorphism.

Kognito's Avatar-Based Suicide Prevention Training for College Students: Results of a Randomized Controlled Trial and a Naturalistic Evaluation.

OBJECTIVE: To evaluate the efficacy and effectiveness of Kognito At Risk for College Students, an online, interactive suicide prevention gatekeeper training. METHODS: In Study 1, a randomized controlled trial was conducted to test the efficacy of Kognito. Retention of participants at follow-up was strong. In Study 2, administrative records were used to follow the help-seeking behavior of Kognito trainees for one academic year, contrasted with untrained students. RESULTS: In Study 1, between-group changes in gatekeeper attitudes were large at time-two, but attenuated modestly by 2-month follow-up. Kognito trainees referred more peers at 2-month follow-up (Cohen's d = .56, p < .05) - training 4 students in Kognito produces 1 more peer referred. In Study 2, the help-seeking rate of Kognito trainees (14.4%) was two-times the rate (6.8%) of untrained students (p < .001). Training 14 students in Kognito leads to 1 more self-referral to the Counseling Center. CONCLUSIONS: This first randomized controlled trial of the college student version of Kognito validates the findings of less rigorous studies. Few brief suicide prevention trainings have shown changes in trainee behaviors such as referrals of at-risk peers and trainees actual help-seeking behavior. These results are promising that Kognito may outperform other similar suicide prevention trainings.

Development and Initial Validation of the Multicultural Personality Inventory (MPI).

Two studies summarize the development and initial validation of the Multicultural Personality Inventory (MPI). In Study 1, the 115-item prototype MPI was administered to 415 university students where exploratory factor analysis resulted in a 70-item, 7-factor model. In Study 2, the 70-item MPI and theoretically related companion instruments were administered to a multisite sample of 576 university students. Confirmatory factory analysis found the 7-factor structure to be a relatively good fit to the data (Comparative Fit Index =.954; root mean square error of approximation =.057), and MPI factors predicted variance in criterion variables above and beyond the variance accounted for by broad personality traits (i.e., Big Five). Study limitations and directions for further validation research are specified.