Museum DNA reveals the demographic history of the endangered Seychelles warbler

The importance of evolutionary conservation – how understanding evolutionary forces can help guide conservation decisions – is widely recognized. However, the historical demography of many endangered species is unknown, despite the fact that this can have important implications for contemporary ecological processes and for extinction risk. Here, we reconstruct the population history of the Seychelles warbler (Acrocephalus sechellensis) – an ecological model species. By the 1960s, this species was on the brink of extinction, but its previous history is unknown. We used DNA samples from contemporary and museum specimens spanning 140 years to reconstruct bottleneck history. We found a 25% reduction in genetic diversity between museum and contemporary populations, and strong genetic structure. Simulations indicate that the Seychelles warbler was bottlenecked from a large population, with an ancestral Ne of several thousands falling to <50 within the last century. Such a rapid decline, due to anthropogenic factors, has important implications for extinction risk in the Seychelles warbler, and our results will inform conservation practices. Reconstructing the population history of this species also allows us to better understand patterns of genetic diversity, inbreeding and promiscuity in the contemporary populations. Our approaches can be applied across species to test ecological hypotheses and inform conservation

Differential effects of tango versus Dance for PD in Parkinson disease

Over half of the general population does not achieve recommended daily levels of physical activity, and activity levels in people with Parkinson disease (PD) are lower than in healthy older adults. Dance can serve as an adjunct to traditional treatments to improve gait, balance, and quality of life in people with PD. This study directly compares a tango dance intervention and a dance intervention based on the Dance for PD model, which integrates multiple dance styles. Eleven people with PD participated in a community-based mixed styles dance intervention called Dance for Parkinson’s (D4PD). Participants in the D4PD group were matched to participants in an ongoing community-based exercise study who participated in tango dance. The groups received 12 weeks of intervention, attending 1-h group classes twice a week. Participants were evaluated off anti-PD medication before and after intervention. Measures of balance, repeated sit-to-stand performance and endurance (mini-balance evaluation systems test, four square step test, five times sit to stand, 6-min walk time) improved from pre to post similarly in both groups. Motor sign severity (movement disorders society unified Parkinson disease rating scale motor subsection) and functional mobility (timed up and go) improved in the tango group and worsened in the D4PD group. Gait velocity was not affected by either intervention. Direct comparisons of different interventions are ­critical for developing optimal exercise interventions designed to specifically target motor impairments in PD. Tango dance interventions may preferentially improve mobility and motor signs in people with PD, compared to D4PD

Are the average gait speeds during the 10 meter and 6 minute walk tests redundant in Parkinson disease?

Published in final edited form as: Gait Posture. 2017 February ; 52: 178–182. doi:10.1016/j.gaitpost.2016.11.033.We investigated the relationships between average gait speed collected with the 10Meter Walk Test (Comfortable and Fast) and 6Minute Walk Test (6MWT) in 346 people with Parkinson disease (PD) and how the relationships change with increasing disease severity. Pearson correlation and linear regression analyses determined relationships between 10Meter Walk Test and 6MWT gait speed values for the entire sample and for sub-samples stratified by Hoehn & Yahr (H&Y) stage I (n=53), II (n=141), III (n=135) and IV (n=17). We hypothesized that redundant tests would be highly and significantly correlated (i.e. r>0.70, p<0.05) and would have a linear regression model slope of 1 and intercept of 0. For the entire sample, 6MWT gait speed was significantly (p<0.001) related to the Comfortable 10 Meter Walk Test (r=0.75) and Fast 10Meter Walk Test (r=0.79) gait speed, with 56% and 62% of the variance in 6MWT gait speed explained, respectively. The regression model of 6MWT gait speed predicted by Comfortable 10 Meter Walk gait speed produced slope and intercept values near 1 and 0, respectively, especially for participants in H&Y stages II-IV. In contrast, slope and intercept values were further from 1 and 0, respectively, for the Fast 10Meter Walk Test. Comfortable 10 Meter Walk Test and 6MWT gait speeds appeared to be redundant in people with moderate to severe PD, suggesting the Comfortable 10 Meter Walk Test can be used to estimate 6MWT distance in this population.This study was funded by the Davis Phinney Foundation, the Parkinson's Disease Foundation, and the National Institutes of Health (R01 NS077959, K12 HD055931, UL1 TR000448). The funding sources had no input related to study design, data collection, or decision to submit for publication. (Davis Phinney Foundation; Parkinson's Disease Foundation; R01 NS077959 - National Institutes of Health; K12 HD055931 - National Institutes of Health; UL1 TR000448 - National Institutes of Health

Oxytocin Attenuates Yohimbine-Induced Reinstatement of Alcohol-Seeking in Female Rats via the Central Amygdala

Alcohol use disorder is a significant public health concern, further exacerbated by an increased risk of relapse due to stress. In addition, factors such as biological sex may contribute to the progression of addiction, as females are especially susceptible to stress-induced relapse. While there have been many studies surrounding potential pharmacological interventions for male stress-induced ethanol reinstatement, research regarding females is scarce. Recently, the neuropeptide oxytocin has gained interest as a possible pharmacological intervention for relapse. The present study examines how oxytocin affects yohimbine-induced reinstatement of ethanol-seeking in female rats using a self-administration paradigm. Adult female rats were trained to press a lever to access ethanol in daily self-administration sessions. Rats then underwent extinction training before a yohimbine-induced reinstatement test. Rats administered with yohimbine demonstrated significantly higher lever response indicating a reinstatement of ethanol-seeking behavior. Oxytocin administration, both systemically and directly into the central amygdala, attenuated the effect of yohimbine-induced reinstatement of ethanol-seeking behavior. The findings from this study establish that oxytocin is effective at attenuating alcohol-relapse behavior mediated by the pharmacological stressor yohimbine and that this effect is modulated by the central amygdala in females. This provides valuable insight regarding oxytocin’s potential therapeutic effect in female stress-induced alcohol relapse