Abbot et al., 2003 Kyle Nash May 12 th , 2009
-
Upload
jessamine-tillman -
Category
Documents
-
view
35 -
download
1
description
Transcript of Abbot et al., 2003 Kyle Nash May 12 th , 2009
![Page 1: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/1.jpg)
Are Subordinates Always Stressed?A comparative analysis of rank differences in cortisol
levels among primates
Abbot et al., 2003Kyle Nash
May 12th, 2009
![Page 2: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/2.jpg)
Agenda
1. Stress and HPA axis review• from Kloet, Joels & Holsboer, 2005
2. Abbott et al., 2003• Intro• Method• Results• Conclusion
3. Discussion
![Page 3: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/3.jpg)
What is Stress?
• Process: Stimulus Response• Stressor: – Stimulus that threatens animal’s physiological
homeostasis (Kloets et al., 2005)
– Physical vs. Psychological (Real vs. Predicted)• Stress Response:– Active maintenance of physiological homeostasis– Sympathetic (Fight or Flight) & Hypothalamic-
Pituitary-Adrenocortical (HPA) systems
![Page 4: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/4.jpg)
Fight or Flight Response
Stressor
Sympathetic Nervous System/
Catecholamines
‘Fight or Flight’
![Page 5: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/5.jpg)
http://www.biology.ucr.edu/people/faculty/Garland/HPA_axis.jpg
PVN
Stressor
Brain Stem (e.g. LC)
‘Limbic’ System
![Page 6: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/6.jpg)
Corticosteroid Receptors• Two types – Both respond to corticosteroids• Minerocorticoid Receptor (MR):– Appraisal, initial stress response– Important in gene transcription activity– More sensitive corticosteroids (10x)
• Glucocorticoids Receptor (GR):– Terminates stress response for recovery (i.e. decrease
CRH production)– Increased sensitivity to corticosteroids during stress– High density in PVN, aminergic & limbic pathways– Promotes stressor-related memory storage
![Page 7: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/7.jpg)
![Page 8: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/8.jpg)
![Page 9: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/9.jpg)
MR x GR
![Page 10: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/10.jpg)
Chronically Stressed Animal• Prolonged and/or repeated exposure to stressor (i.e. prolonged increase
in corticosteroids) can have maladaptive consequences – Hypertension, type-II diabetes, ulcers, etc.
• Chronic stress Neuroendocrine change– hippocampal (CA3) atrophy, reduced proliferation (MR)– GRs and MRs downregulated– Diminished Denate Granule cell turnover rate– Reduced 5-HT receptor function– Reduced LTP/Facilitated LTD
• Produce a Stress-typology• ‘Coping’ can disrupt maladaptive changes
– offspring of ‘caring’ rat mothers, higher hippocampal GR gene expression and decreased anxiety-related behaviour
• Stress experience (stressors and coping) and genetic background cause long-term changes
![Page 11: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/11.jpg)
Summary
• Stressors activate sympathetic and HPA systems
• Glucocorticoids regulate stress response through MR and GR interaction
• Prolonged stress physiological problems and neuroendocrine funtioning
• Individual differences in genetics and experience important in stress response
![Page 12: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/12.jpg)
Rank and Stress
• Stress levels may be higher in subordinates– Low access to resources, physical and social
stressors, low ‘coping’ opportunities
• Certain subordinate primates– elevated glucocorticoids and catecholimines– higher blood pressure– Stress-related pathologies
• Not consistent for all primates
![Page 13: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/13.jpg)
Abbot et al., 2005
• Conflicting results on rank and stress
• Purpose– Survey researchers (quasi-meta-analysis)
– Rank, Sex, Species Stress
– Looked at both physical/psychological factors
![Page 14: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/14.jpg)
Method
• Questionnaire: 6 Domains, 17 questionsI. What is it like to be a dominant individual in this
society?II. What is it like to be a subordinate individual in this
society?III. What are the typical routes by which ranks change?IV. What is the nature of revolutionary change in
hierarchies?V. The role of kinship.VI. Non-agonistic factors relevant to the stress-response.
• 0 (Not at all) – 3 (Highly applicable)
![Page 15: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/15.jpg)
Method: Sample 4 Old world (e.g. Rhesus) 3 New World (e.g. Marmoset)
• Subordinates: indicated by expert of each sample• Analyses: by species and sometimes sex • 10 groups in total, large variance in group dynamics
![Page 16: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/16.jpg)
Method
• DV: Relative Cortisol– Basal levels– Circulatory or urinary– Relative to dominant monkeys, controls for
species differences• i.e. 100% = equal cortisol levels
![Page 17: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/17.jpg)
Analyses• Two types of analysis1. Multiple Regression with independent contrasts – Flips variables from dependent (i.e. similar species) to
independent– After data collection, excluded questions based on
• missing values (5)• High r’s with other questions or Low r’s with cortisol (4)• 8 total questions
2. Data Tree - decision algorithm from response variability predicted– Different excluded values– Used 4 questions from 8 (above) in regression
![Page 18: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/18.jpg)
Tree-Based Method – Single Branch
• (1) If Question 1A is >X, then this predicts relative cortisol levels = Y1% (branch 1).
• (2) If Question 1A is <X, then this predicts relative cortisol levels = Y2% (branch 2).
• Overall Tree = Minimum Branches for Maximum Predictive Power
Q 1A
Y2Y1
![Page 19: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/19.jpg)
![Page 20: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/20.jpg)
Final Q’s Multiple Regression• 1A: How much of a role does aggression play in the attainment of
dominance?• 2A: How frequently are subordinates subject to stressors?• 2B: How available is social support for subordinates?• 2F: Overall, how much should subordinate status be thought of as
an undesirable state actively imposed by more dominant animals?• 3A: Do animals rise in the hierarchy through strenuous challenge of
the status quo?• 4A: How often do such “revolutions” occur?• 5A: How important is kinship in understanding interactions among
these animals?• 6A: Are there circumstances in which one has to invoke a
physiological adaptation to subordinate status, rather than a response to agonistic behavior, to make sense of the profile of a particular stress hormone?
• Two significant predictors, 2A and 2B
![Page 21: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/21.jpg)
Results: 2A - Social Stressors
![Page 22: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/22.jpg)
2B - Social Support
![Page 23: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/23.jpg)
Final Q’s for Tree-Based Analysis
• 2A: How frequently are subordinates subject to stressors?
• 2B: How available is social support for subordinates?
• 3A: Do animals rise in the hierarchy through strenuous challenge of the status quo?
• 5A: How important is kinship in understanding interactions among these animals?
![Page 24: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/24.jpg)
![Page 25: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/25.jpg)
Discussion• Subordinates do not always express higher levels of
cortisol• Important factors:– Stressors frequency– Social support– Relevance of kinship
• Possible neuroendocrine mechanisms– Increased stressors decreased GRs diminished
negative feedback in stress response cortisol– Outlets (social support) diminishes cortisol levels– Kinship variable could predict both stressor frequency and
social support quality
![Page 26: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/26.jpg)
Problems
• Relative measure of cortisol• consider the cortisol levels for dominant monkeys
• Questionnaire • Exclusions were largely subjective
• Authors were respondents
![Page 27: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/27.jpg)
Discussion• Other important factors? – Other outlets or displacement behaviours?– Simple stressor disruption?– i.e., allowing rats access to a running wheel decreases
the magnitude of the glucocorticoid response to shock
• Coping mechanisms: MRxGR? – Stops GR downregulation?
• Stressor controllability inhibits behavioural response
Coping? Social Support?
![Page 28: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/28.jpg)
References• Unless otherwise noted, figures and tables from
Abbot et al., 2003.• Sapolsky, R.M., Krey, L., McEwen, B., (1984).
Stress down-regulates corticosterone receptors in a site-specific manner in the brain. Endocrinology, 114, 287–292.
• Kloet, Joels, & Holsboer, (2005). Stress and the brain: From adaptation to disease. Nature Reviews: Neuroscience, 6, 463-475.
• http://www.biology.ucr.edu/people/faculty/Garland/HPA_axis.jpg
![Page 29: Abbot et al., 2003 Kyle Nash May 12 th , 2009](https://reader036.fdocuments.in/reader036/viewer/2022062304/568130a8550346895d96af1b/html5/thumbnails/29.jpg)