Exercise Associated with Cognitive Function in Older Men with Prostate Cancer Undergoing Androgen Deprivation Therapy

BACKGROUND

To examine associations between exercise and cognitive function in older men undergoing hormone therapy for prostate cancer.

METHOD

Men ≥ 65 years old with prostate cancer, currently undergoing androgen deprivation therapy for ≥ 6 months (n = 50), completed the Godin-Shephard Leisure-Time Physical Activity Questionnaire, and standard neuropsychological tests. Pearson's correlations and linear regressions were used to examine associations between exercise and cognitive performance.

RESULTS

Exercise was significantly positively correlated with performance on tests of memory, attention, and executive function. Linear regressions showed that when controlling for age and education, exercise remained a significant predictor of attention and executive function performance (p < 0.05), and showed moderate, but statistically non-significant effects on memory performance (p < 0.10).

CONCLUSION

Greater exercise is associated with better functioning in multiple cognitive domains in men with prostate cancer undergoing hormone therapy, providing proof-of-concept evidence that exercise may be a feasible intervention to limit cognitive dysfunction in prostate cancer patients.

Use of Mentholated Cigarettes and Likelihood of Smoking Cessation in the United States: A Meta-Analysis

INTRODUCTION

Previous qualitative reviews have summarized evidence of an association between menthol cigarette use and likelihood of smoking cessation. The objective of this meta-analysis was to provide a quantitative summary of effect sizes, their variability, and factors related to the variability in effect size for the association between menthol use and likelihood of smoking cessation.

METHODS

We systematically searched Medline, PsycINFO, and Embase for prospective and cross-sectional studies of the association between menthol use and smoking cessation. We analyzed data with random effects meta-analyses and meta-regression.

RESULTS

Our review identified 22 reports from 19 studies of the association between menthol use and cessation. All identified study samples included only US smokers, with one exception that included both Canadian and US smokers. Our overall model did not demonstrate a significant association between menthol use and cessation; however, menthol users were significantly less likely to quit among blacks/African American smokers (odds ratio = 0.88).

CONCLUSIONS

Among blacks/African Americans predominantly in the US menthol users have approximately 12% lower odds of smoking cessation compared to non-menthol users. This difference is likely the result of the tobacco industry's ongoing marketing influence on the black/African American Community, suggesting that a menthol ban may have a unique public health benefit for black/African American smokers by encouraging quitting behavior.

IMPLICATIONS

This study adds a quantitative summary of the association between menthol cigarette use and smoking cessation in the United States. Findings of an association with lower likelihood of cessation among black/African American smokers, likely resulting from the tobacco industry's marketing influence, support the ban of menthol flavoring as part of a comprehensive tobacco control effort to increase cessation among black/African American smokers.

Doxorubicin and cyclophosphamide induce cognitive dysfunction and activate the ERK and AKT signaling pathways

Chemotherapy is associated with long-term cognitive deficits in breast cancer survivors. Studies suggest that these impairments result in the loss of cognitive reserve and/or induce a premature aging of the brain. This study has been aimed to determine the potential underlying mechanisms that induce cognitive impairments by chemotherapeutic agents commonly used in breast cancer. Intact and ovariectomized (OVX) female rats were treated intravenously with either saline or a combination of cyclophosphamide (40 mg/kg) and doxorubicin (4 mg/kg). All subjects were tested for anxiety, locomotor activity, working, visual and spatial memory consecutively. Although anxiety and visual memory were not affected, chemotherapy significantly decreased locomotor activity and impaired working and spatial memory in female rats, independent of their hormonal status. The cognitive deficits observed are hippocampal dependent. Therefore, as a first step to identity the potential signaling pathways involved in this cognitive dysfunction, the protein levels of extracellular signal-regulated kinase 1/2 (Erk1/2), Akt (neuroprotectant) BDNF and (structural protein) PSD95 in hippocampal lysates were measured. Erk1/2 and Akt pathways are known to modulate synaptic plasticity, neuronal survival, aging and cancer. We found an increased activation of Erk1/2 and Akt as well as an increase in the protein levels of PSD95 in OVX female rodents. However, OVX females had a higher overall BDNF level, independent of chemotherapy. These studies provide additional evidence that commonly used chemotherapeutic agents affect cognitive function and impact synaptic plasticity/aging molecules which may be part of the underlying biology explaining cognitive change and can be potential therapeutic targets.

Prenatal cocaine exposure increases anxiety, impairs cognitive function and increases dendritic spine density in adult rats: influence of sex

Cocaine exposure during pregnancy can impact brain development and have long-term behavioral consequences. The present study examined the lasting consequences of prenatal cocaine (PN-COC) exposure on the performance of cognitive tasks and dendritic spine density in adult male and female rats. From gestational day 8 to 20, dams were treated daily with 30 mg/kg (ip) of cocaine HCl or saline. At 62 days of age, offspring were tested consecutively for anxiety, locomotion, visual memory and spatial memory. PN-COC exposure significantly increased anxiety in both sexes. Object recognition (OR) and placement (OP) tasks were used to assess cognitive function. Behavioral tests consisted of an exploration trial (T1) and a recognition trial (T2) that were separated by an inter-trial delay of varying lengths. Male PN-COC subjects displayed significantly less time investigating new objects or object locations during T2 in both OR and OP tasks. By contrast, female PN-COC subjects exhibited impairments only in OR and only at the longest inter-trial delay interval. In addition, gestational cocaine increased dendritic spine density in the prefrontal cortex and nucleus accumbens in both genders, but only females had increased spine density in the CA1 region of the hippocampus. These data reveal that in-utero exposure to cocaine results in enduring alterations in anxiety, cognitive function and spine density in adulthood. Moreover, cognitive deficits were more profound in males than in females.

Anabolic steroids have long-lasting effects on male social behaviors

Anabolic androgenic steroids (AAS) use by adolescents is steadily increasing. Adolescence involves remodeling of steroid-sensitive neural circuits that mediate social behaviors, and previous studies using animal models document effects of AAS on male social behaviors. The present experiments tested whether AAS have persistent and more pronounced behavioral consequences when drug exposure occurs during adolescence as compared to exposure in adulthood. Male Syrian hamsters were injected daily for 14 days with either vehicle or an AAS cocktail containing testosterone cypionate (2 mg/kg), nandrolone decanoate (2 mg/kg), and boldenone undecylenate (1 mg/kg), either during adolescence (27-41 days of age) or adulthood (63-77 days of age). As adults, subjects were tested two or four weeks after the last injection for either sexual behavior with a receptive female or male-male agonistic behavior in a resident-intruder test. Compared with vehicle-treated males, AAS-treated males, regardless of age of treatment, displayed fewer long intromissions and a significant increase in latency to the first long intromission, indicative of reduced potential to reach sexual satiety. Increased aggression was observed in males exposed to AAS compared with males treated with vehicle, independently of age of AAS treatment. However, unlike hamsters exposed to AAS in adulthood, hamsters exposed to AAS during adolescence did not display any submissive or risk-assessment behaviors up to 4 weeks after discontinuation of AAS treatment. Thus, AAS have long-lasting effects on male sexual and agonistic behaviors, with AAS exposure during adolescence resulting in a more pronounced reduction in submissive behavior compared to AAS exposure in adulthood.

Testosterone programs adult social behavior before and during, but not after, adolescence

Whereas the adolescent brain is a major target for gonadal hormones, our understanding of hormonal influences on adolescent neural and behavioral development remains limited. These experiments investigated how variations in the timing of testosterone (T) exposure, relative to adolescence, alters the strength of steroid-sensitive neural circuits underlying social behavior in male Syrian hamsters. Experiment 1 simulated early, on-time, and late pubertal development by gonadectomizing males on postnatal d 10 and treating with SILASTIC brand T implants for 19 d before, during, or after adolescence. T treatment before or during, but not after, adolescence facilitated mating behavior in adulthood. In addition, preadolescent T treatments most effectively increased mating behavior overall, indicating that the timing of exposure to pubertal hormones contributes to individual differences in adult behavior. Experiment 2 examined the effects of preadolescent T treatment on behavior and brain regional volumes within the mating neural circuit of juvenile males (i.e. still preadolescent). Although preadolescent T treatment did not induce reproductive behavior in juvenile males, it did increase volumes of the bed nucleus of the stria terminalis, sexually dimorphic nucleus, posterodorsal medial amygdala, and posteroventral medial amygdala to adult-typical size. In contrast, juvenile anterodorsal medial amygdala and ventromedial hypothalamus volumes were not changed by preadolescent T treatment yet differed significantly in volume from adult controls, suggesting that further maturation of these brain regions during adolescence is required for the expression of male reproductive behavior. Thus, adolescent maturation of social behavior may involve both steroid-independent and -dependent processes, and adolescence marks the end of a postnatal period of sensitivity to steroid-dependent organization of the brain.

Anabolic androgenic steroids differentially affect social behaviors in adolescent and adult male Syrian hamsters

Anabolic androgenic steroids (AAS) are synthetic derivatives of testosterone used by over half a million adolescents in the United States for their tissue-building potency and performance-enhancing effects. AAS also affect behavior, including reports of heightened aggression and changes in sexual libido. The expression of sexual and aggressive behaviors is a function of complex interactions among hormones, social context, and the brain, which is extensively remodeled during adolescence. Thus, AAS may have different consequences on behavior during adolescence and adulthood. Using a rodent model, these studies directly compared the effects of AAS on the expression of male sexual and aggressive behaviors in adolescents and adults. Male Syrian hamsters were injected daily for 14 days with either vehicle or an AAS cocktail containing testosterone cypionate (2 mg/kg), nandrolone decanoate (2 mg/kg), and boldenone undecylenate (1 mg/kg), either during adolescence (27-41 days of age) or in adulthood (63-77 days of age). The day after the last injection, males were tested for either sexual behavior with a receptive female or agonistic behavior with a male intruder. Adolescent males treated with AAS showed significant increases in sexual and aggressive behaviors relative to vehicle-treated adolescents. In contrast, AAS-treated adults showed significantly lower levels of sexual behavior compared with vehicle-treated adults and did not show heightened aggression. Thus, adolescents, but not adults, displayed significantly higher behavioral responses to AAS, suggesting that the still-developing adolescent brain is more vulnerable than the adult brain to the adverse consequences of AAS on the nervous system and behavior.