The Lasting Effects of Perceived Predation Risk on the Avian Brain and Behaviour

Predators affect prey populations not only through direct killing, but also through perceived predation risk – the ‘fear’ of predators. Responding to predation risk is critical for prey survival, however perceived predation risk can have lasting effects ranging from individual changes in neurobiology up to population level effects. I manipulated perceived predation risk using auditory playbacks of predators or non-predators in wild caught black-capped chickadees (Poecile atricapillus) in acoustic isolation and wild caught brown-headed cowbirds (Molothrus ater) in large outdoor aviaries. I found changes in dendritic morphology and inhibited neurogenesis in response to increased perceived predation risk lasting at least one week. I also found changes in both escape behaviour and in the response to a conspecific alarm call. My research shows that perceived predation risk has long-lasting effects on both the brain and behaviour, with applications for both ecologists and biomedical researchers

P31. Assessing the long term effects of perceived predation risk on the avian brain

Predators affect prey populations not only through direct killing, but also through the perception of predation risk. Responding to predator threats is critical for prey survival, however perceived predation risk can have lasting effects ranging from individual changes in neurobiology up to the population level. My research focuses on the lasting effects of predator ‘fear’ on the avian brain. I will be using auditory playbacks to manipulate predation risk in black-capped chickadees (Poecile atricapillus) in acoustic isolation and brown-headed cowbirds (Molothrus ater) in large outdoor aviaries. Lasting behavioural changes have been found in black-capped chickadees one week after exposure to increased perceived predation risk, and I will be looking for long lasting changes in brain morphology and activation in regions thought to be involved in the avian fear network. My research aims to connect laboratory methods used to quantify the effects of fear in the brain with behavioural and physiological changes found from perceived predation risk in the field

Comparing the traditional and Multiple Mini Interviews in the selection of post-graduate medical trainees

Background: The traditional, panel style interview and the multiple mini interview (MMI) are two options to use in the selection of medical trainees with each interview format having inherent advantages and disadvantages. Our aim was to compare the traditional and MMI on the same cohort of postgraduate applicants to the Department of Otolaryngology – Head & Neck Surgery at the University of Toronto.Method: Twenty-seven applicants from the 2010 Canadian Residency Matching Service selected for interview at the University of Toronto, Department of Otolaryngology – Head & Neck Surgery were included in the study. Each applicant participated in both a traditional interview and MMI.Results:  Traditional interviews marked out of a total maximum score of 570.  On the traditional interview, scores ranged from 397-543.5 (69.6 - 95.3%), the mean was 460.2. The MMI maximum score was out of 180. MMI scores ranged from 93 – 146 (51.7 - 81.1%) with a mean of 114.8. Traditional interview total scores were plotted against MMI total scores. Scores correlated reasonably well, Pearson Correlation = 0.315 and is statistically significant at p = 0.001. Inter-interview reliability for the two interview methods was 0.038, with poor overall agreement 0.07%.Conclusions: MMI and traditional interview scores are correlated but do not reliably lead to the same rank order.  We have demonstrated that these two interview formats measure different characteristics.  One format may also be less reliable leading to greater variation in final rank.  Further validation research is certainly required.Key Words: Multiple mini interview; medical education; traditional interview; postgraduate admission

Comparing the traditional and Multiple Mini Interviews in the selection of post-graduate medical trainees

Background: The traditional, panel style interview and the multiple mini interview (MMI) are two options to use in the selection of medical trainees with each interview format having inherent advantages and disadvantages. Our aim was to compare the traditional and MMI on the same cohort of postgraduate applicants to the Department of Otolaryngology – Head & Neck Surgery at the University of Toronto.Method: Twenty-seven applicants from the 2010 Canadian Residency Matching Service selected for interview at the University of Toronto, Department of Otolaryngology – Head & Neck Surgery were included in the study. Each applicant participated in both a traditional interview and MMI.Results:  Traditional interviews marked out of a total maximum score of 570.  On the traditional interview, scores ranged from 397-543.5 (69.6 - 95.3%), the mean was 460.2. The MMI maximum score was out of 180. MMI scores ranged from 93 – 146 (51.7 - 81.1%) with a mean of 114.8. Traditional interview total scores were plotted against MMI total scores. Scores correlated reasonably well, Pearson Correlation = 0.315 and is statistically significant at p = 0.001. Inter-interview reliability for the two interview methods was 0.038, with poor overall agreement 0.07%.Conclusions: MMI and traditional interview scores are correlated but do not reliably lead to the same rank order.  We have demonstrated that these two interview formats measure different characteristics.  One format may also be less reliable leading to greater variation in final rank.  Further validation research is certainly required.Key Words: Multiple mini interview; medical education; traditional interview; postgraduate admission

Predator-induced fear causes PTSD-like changes in the brains and behaviour of wild animals

© 2019, The Author(s). Predator-induced fear is both, one of the most common stressors employed in animal model studies of post-traumatic stress disorder (PTSD), and a major focus of research in ecology. There has been a growing discourse between these disciplines but no direct empirical linkage. We endeavoured to provide this empirical linkage by conducting experiments drawing upon the strengths of both disciplines. Exposure to a natural cue of predator danger (predator vocalizations), had enduring effects of at least 7 days duration involving both, a heightened sensitivity to predator danger (indicative of an enduring memory of fear), and elevated neuronal activation in both the amygdala and hippocampus – in wild birds (black-capped chickadees, Poecile atricapillus), exposed to natural environmental and social experiences in the 7 days following predator exposure. Our results demonstrate enduring effects on the brain and behaviour, meeting the criteria to be considered an animal model of PTSD – in a wild animal, which are of a nature and degree which can be anticipated could affect fecundity and survival in free-living wildlife. We suggest our findings support both the proposition that PTSD is not unnatural, and that long-lasting effects of predator-induced fear, with likely effects on fecundity and survival, are the norm in nature

The inferior turbinate flap in skull base reconstruction

BACKGROUND: As the indications for expanded endonasal approaches continue to evolve, alternative reconstructive techniques are needed to address increasingly complex surgical skull base defects. In the absence of the nasoseptal flap, we describe our experience with the posterior pedicle inferior turbinate flap (PPITF) in skull base reconstruction. DESIGN: Case series. SETTING: Academic tertiary care centre. METHODS: Patients who underwent reconstruction of the skull base with the PPITF were identified. Medical records were reviewed for demographic, presentation, treatment, follow-up, surgical and outcomes data. MAIN OUTCOME MEASURES: Flap survival, adequacy of seal, and complications. RESULTS: Two patients with residual/recurrent pituitary adenomas met the inclusion criteria. The nasoseptal flap was unavailable in each case due to a prior septectomy. Salvage of the original nasoseptal flap was not possible, as it did not provide adequate coverage of the resultant defect due to contraction from healing. All PPITFs healed uneventfully and covered the entire defect. No complications were observed in the early post-operative period. Endoscopic techniques and limitations of the PPITF are also discussed. CONCLUSIONS: Our clinical experience supports the PPITF to be a viable alternative for reconstruction of the skull base in the absence of the nasoseptal flap