Glucocorticoid receptor expression in blood, but not across brain regions, reveals long-term effects of early life adversity in zebra finches

Early-life environment can affect organisms for life on many levels. The glucocorticoid receptor (GR) gene has a pivotal role mediating organismal physiological and behavioral responses to environmental change, and is sensitive to early-life environmental conditions and epigenetic programming. Longitudinal studies require non-lethal sampling of peripheral tissues (e.g. blood), but this approach is dependent on the extent to which GR expression in peripheral tissues covaries with GR expression in central tissues. To test for the long-term effects of early life adversity on GR expression across brain and peripheral tissues, we manipulated developmental conditions of captive zebra finches (n=45), rearing them in either benign or harsh conditions through manipulation of parental foraging costs. We measured relative GR mRNA expression in blood and five brain regions in adulthood: hippocampus, hypothalamus, amygdala, ventral striatum, and the nidopallium caudolaterale (analogous to the mammalian prefrontal cortex), using qPCR. We further tested whether GR expression was modulated by natal brood size (which affected growth), age at sampling, and sex. GR expression correlations between tissues varied widely in magnitude and direction, ranging from -0.27 to +0.80, indicating that our understanding of developmental effects on GR expression and associated phenotypes needs to be region specific rather than organism wide. A more consistent pattern was that GR expression increased with age in blood, ventral striatum and hippocampus; GR expression was independent of age in other tissues. Developmental treatment did not affect GR expression in any of the tissues measured directly, but in blood and ventral striatum of adult females we found a positive correlation between nestling mass and GR expression. Thus, GR expression in blood reflected early life conditions as reflected in growth in adult females, showing patterns in one brain tissue, but not ubiquitous across brain regions. These results point at sex-dependent physiological constraints during development, shaping early life effects on GR expression in females only. Further study is required to investigate whether these tissue-dependent effects more generally reflect tissue-dependent long-term effects of early life adversity. This, together with investigating the physiological consequences of GR expression levels on individual performance and coping abilities, will be fundamental towards understanding the mechanisms mediating long-term impacts of early life, and the extent to which these can be quantified through non-lethal sampling.</p

Experimentally manipulated food availability affects offspring quality but not quantity in zebra finch meso‑populations

Food availability modulates survival, reproduction and thereby population size. In addition to direct effects, food availability has indirect effects through density of conspecifics and predators. We tested the prediction that food availability in isolation affects reproductive success by experimentally manipulating food availability continuously for 3 years in zebra finches (Taeniopygia guttata) housed in outdoor aviaries. To this end, we applied a technique that mimics natural variation in food availability: increasing the effort required per food reward without affecting diet. Lower food availability resulted in a slight delay of start of laying and fewer clutches per season, but did not affect clutch size or number of offspring reared per annum. However, increasing foraging costs substantially reduced offspring growth. Thus, food availability in isolation did not impact the quantity of offspring reared, at the expense of offspring quality. Growth declined strongly with brood size, and we interpret the lack of response with respect to offspring number as an adaptation to environments with low predictability, at the time of egg laying, of food availability during the period of peak food demand, typically weeks later. Manipulated natal brood size of the parents did not affect reproductive success. Individuals that were more successful reproducers were more likely to survive to the next breeding season, as frequently found in natural populations. We conclude that the causal mechanisms underlying associations between food availability and reproductive success in natural conditions may be more complex than usually assumed. Experiments in semi-natural meso-populations can contribute to further unravelling these mechanisms

Effects of early-life conditions on innate immune function in adult zebra finches

Early life conditions can affect individuals for life, with harsh developmental conditions resulting in lower fitness, but the underlying mechanisms are not well understood. We hypothesized that immune function may be part of the underlying mechanism, when harsh developmental conditions result in less effective immune function. We tested this hypothesis by comparing innate immune function between zebra finches (Taeniopygia guttata) in adulthood (n=230; age 108–749 days) that were reared in either small or large broods. We used this experimental background to follow up our earlier finding that finches reared in large broods have a shorter lifespan. To render a broad overview of innate immune function, we used an array of six measures: bacterial killing capacity, hemagglutination, hemolysis, haptoglobin, nitric oxide and ovotransferrin. We found no convincing evidence for effects of natal brood size on any of the six measures of innate immune function. This raised the question whether the origin of variation in immune function was genetic, and we therefore estimated heritabilities using animal models. However, we found heritability estimates to be low (range 0.04–0.11) for all measured immune variables, suggesting variation in innate immune function can largely be attributed to environmental effects independent of early-life conditions as modified by natal brood size

Effects of manipulated food availability and seasonality on innate immune function in a passerine

The innate immune system is essential for survival, yet many immune traits are highly variable between and within individuals. In recent years, attention has shifted to the role of environmental factors in modulating this variation. A key environmental factor is food availability, which plays a major role in shaping life histories, and may affect resource allocation to immune function through its effect on nutritional state. We developed a technique to permanently increase foraging costs in seed-eating birds, and leveraged this technique to study the effects of food availability on the innate immune system over a 3-year period in 230 zebra finches housed in outdoor aviaries. The immune components we studied were haptoglobin, ovotransferrin, nitric oxide, natural antibodies through agglutination, complement-mediated lysis, and killing capacity of Escherichia coli and Candida albicans, covering a broad spectrum of the innate immune system. We explored the effects of food availability in conjunction with other potentially important variables: season, age, sex and manipulated natal brood size. Increased foraging costs affected multiple components of the immune system, albeit in a variable way. Nitric oxide and agglutination levels were lower under harsh foraging conditions, while Escherichia coli killing capacity was increased. Agglutination levels also varied seasonally, but only at low foraging costs. C. albicans killing capacity was lower in winter, and even more so for animals in harsh foraging conditions that were raised in large broods. Effects of food availability on ovotransferrin were also seasonal, and only apparent in males. Haptoglobin levels were independent of foraging costs and season. Males had higher levels of immune function than females for three of the measured immune traits. Innate immune function was independent of age and manipulated natal brood size. Our finding that food availability affects innate immune function suggests that fitness effects of food availability may at least partially be mediated by effects on the immune system. However, food availability effects on innate immunity varied in direction between traits, illustrating the complexity of the immune system and precluding conclusions on the level of disease resistance

Does mixing inhaler devices lead to unchecked inhaler technique errors in patients with COPD? : Findings from the cross-sectional observational MISMATCH study

Funding Information: The members of the MISMATCH study group would like to acknowledge Titia Klemmeijer (founder of the IMIS foundation; 'Inhalatie Medicatie Instruction School') for her assistance in formulating the list of additional errors, and Chantal Arling, Thomas le Rutte & Landy Torre for their time and efforts to perform the reassessments of the video recordings. Finally, they would like to thank the participants who generously gave their time to participate in the PIFotal study and provided informed consent to use their video/data for future research. This work was supported by Chiesi Pharmaceuticals. The PIFotal study was cofunded by Boehringer Ingelheim.Peer reviewe

Does mixing inhaler devices lead to unchecked inhaler technique errors in patients with COPD?:Findings from the cross-sectional observational MISMATCH study

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) may be prescribed multiple inhalers that require different techniques for optimal performance. Mixing devices has been associated with poorer COPD outcomes suggesting that it leads to inappropriate inhaler technique. However, empirical evidence is lacking.AIMS: Compare the nature and frequency of dry powder inhaler (DPI) technique errors in patients with COPD using (1) a single DPI or (2) mixed-devices (a DPI and pressurised metered dose inhaler (pMDI)).METHODS: Data from the PIFotal study-a cross-sectional study on Peak Inspiratory Flow in patients with COPD using a DPI as maintenance therapy, capturing data from 1434 patients on demographic characteristics, COPD health status and inhaler technique-were used to select 291 patients using mixed-devices. Frequency matching based on country of residence and DPI device type was used to select 291 patients using a DPI-only for comparison. Predetermined checklists were used for the evaluation of DPI video recordings and complemented with additional errors that were observed in ≥10%. Error proportions were calculated for the (1) individual and total number of errors, (2) number of critical errors and (3) number of pMDI-related errors.RESULTS: The study sample contained 582 patients (mean (SD) age 69.6 (9.4) years, 47.1% female). DPI technique errors were common, but not significantly different between the groups. The majority of patients made at least one critical error (DPI-only: 90.7% vs mixed-devices: 92.8%). Proportions of total, 'pMDI-related' and critical errors did not significantly differ between the groups.CONCLUSION: The nature and frequency of inhaler technique errors did not substantially differ between patients prescribed with a single DPI and mixed-devices. Currently, 'pMDI-related errors' in DPI use are not accounted for in existing checklists.TRIAL REGISTRATION NUMBER: ENCEPP/EUPAS48776.</p

Does mixing inhaler devices lead to unchecked inhaler technique errors in patients with COPD?:Findings from the cross-sectional observational MISMATCH study

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) may be prescribed multiple inhalers that require different techniques for optimal performance. Mixing devices has been associated with poorer COPD outcomes suggesting that it leads to inappropriate inhaler technique. However, empirical evidence is lacking.AIMS: Compare the nature and frequency of dry powder inhaler (DPI) technique errors in patients with COPD using (1) a single DPI or (2) mixed-devices (a DPI and pressurised metered dose inhaler (pMDI)).METHODS: Data from the PIFotal study-a cross-sectional study on Peak Inspiratory Flow in patients with COPD using a DPI as maintenance therapy, capturing data from 1434 patients on demographic characteristics, COPD health status and inhaler technique-were used to select 291 patients using mixed-devices. Frequency matching based on country of residence and DPI device type was used to select 291 patients using a DPI-only for comparison. Predetermined checklists were used for the evaluation of DPI video recordings and complemented with additional errors that were observed in ≥10%. Error proportions were calculated for the (1) individual and total number of errors, (2) number of critical errors and (3) number of pMDI-related errors.RESULTS: The study sample contained 582 patients (mean (SD) age 69.6 (9.4) years, 47.1% female). DPI technique errors were common, but not significantly different between the groups. The majority of patients made at least one critical error (DPI-only: 90.7% vs mixed-devices: 92.8%). Proportions of total, 'pMDI-related' and critical errors did not significantly differ between the groups.CONCLUSION: The nature and frequency of inhaler technique errors did not substantially differ between patients prescribed with a single DPI and mixed-devices. Currently, 'pMDI-related errors' in DPI use are not accounted for in existing checklists.TRIAL REGISTRATION NUMBER: ENCEPP/EUPAS48776.</p

Does mixing inhaler devices lead to unchecked inhaler technique errors in patients with COPD?:Findings from the cross-sectional observational MISMATCH study

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) may be prescribed multiple inhalers that require different techniques for optimal performance. Mixing devices has been associated with poorer COPD outcomes suggesting that it leads to inappropriate inhaler technique. However, empirical evidence is lacking.AIMS: Compare the nature and frequency of dry powder inhaler (DPI) technique errors in patients with COPD using (1) a single DPI or (2) mixed-devices (a DPI and pressurised metered dose inhaler (pMDI)).METHODS: Data from the PIFotal study-a cross-sectional study on Peak Inspiratory Flow in patients with COPD using a DPI as maintenance therapy, capturing data from 1434 patients on demographic characteristics, COPD health status and inhaler technique-were used to select 291 patients using mixed-devices. Frequency matching based on country of residence and DPI device type was used to select 291 patients using a DPI-only for comparison. Predetermined checklists were used for the evaluation of DPI video recordings and complemented with additional errors that were observed in ≥10%. Error proportions were calculated for the (1) individual and total number of errors, (2) number of critical errors and (3) number of pMDI-related errors.RESULTS: The study sample contained 582 patients (mean (SD) age 69.6 (9.4) years, 47.1% female). DPI technique errors were common, but not significantly different between the groups. The majority of patients made at least one critical error (DPI-only: 90.7% vs mixed-devices: 92.8%). Proportions of total, 'pMDI-related' and critical errors did not significantly differ between the groups.CONCLUSION: The nature and frequency of inhaler technique errors did not substantially differ between patients prescribed with a single DPI and mixed-devices. Currently, 'pMDI-related errors' in DPI use are not accounted for in existing checklists.TRIAL REGISTRATION NUMBER: ENCEPP/EUPAS48776.</p

Supplemental data. Gerritsma_AnBeh

Research data Gerritsma et al., Animal Behaviou

Data from: Effects of manipulated food availability and seasonality on innate immune function in a passerine

1. The innate immune system is essential for survival, yet many immune traits are highly variable between and within individuals. In recent years, attention has shifted to the role of environmental factors in modulating this variation. A key environmental factor is food availability, which plays a major role in shaping life-histories, and may affect resource allocation to immune function through its effect on nutritional state. 2. We developed a technique to permanently increase foraging costs in seed-eating birds, and leveraged this technique to study the effects of food availability on the innate immune system over a three-year period in 230 zebra finches housed in outdoor aviaries. The immune components we studied were haptoglobin, ovotransferrin, nitric oxide, natural antibodies through agglutination, complement-mediated lysis, and killing capacity of Escherichia coli and Candida albicans, covering a broad spectrum of the innate immune system. We explored effects of food availability in conjunction with other potentially important variables: season, age, sex, and manipulated natal brood size. 3. Increased foraging costs affected multiple components of the immune system, albeit in a variable way. Nitric oxide and agglutination levels were lower under harsh foraging conditions, while Escherichia coli killing capacity was increased. Agglutination levels also varied seasonally, but only at low foraging costs. C. albicans' killing capacity was lower in winter, and even more so for animals in harsh foraging conditions that were raised in large broods. Effects of food availability on ovotransferrin were also seasonal, and only apparent in males. Haptoglobin levels were independent of foraging costs and season. 4. Males had higher levels of immune function than females for 3 of the measured immune traits. Innate immune function was independent of age and manipulated natal brood size. 5. Our finding that food availability affects innate immune function suggests that fitness effects of food availability may at least partially be mediated by effects on the immune system. However, food availability effects on innate immunity varied in direction between traits, illustrating the complexity of the immune system and precluding conclusions on the level of disease resistance