Spatial cognitive ability is associated with longevity in food-caching chickadees.

Cognitive abilities are hypothesized to affect survival and life span in nonhuman animals. However, most tests of this hypothesis have relied on interspecific comparisons of indirect measures of cognitive ability, such as brain size. We present direct evidence that individual variation in cognitive abilities is associated with differences in life span in a wild food caching bird.

Relative breeding timing and reproductive success of a resident montane bird species.

Wild populations appear to synchronize their reproductive phenology based on numerous environmental and ecological factors; yet, there is still individual variation in the timing of reproduction within populations and such variation may be associated with fitness consequences. For example, many studies have documented a seasonal decline in reproductive fitness, but breeding timing may have varying consequences across different environments. Using 11 years of data, we investigated the relationship between relative breeding timing and reproductive success in resident mountain chickadees () across two elevational bands in the Sierra Nevada mountains, USA.

Integrated stress response activator halofuginone protects mice from diabetes-like phenotypes.

The integrated stress response (ISR) is a vital signaling pathway initiated by four kinases, PERK, GCN2, HRI and PKR, that ensure cellular resilience and protect cells from challenges. Here, we investigated whether increasing ISR signaling could rescue diabetes-like phenotypes in a mouse model of diet-induced obesity (DIO). We show that the orally available and clinically approved GCN2 activator halofuginone (HF) can activate the ISR in mouse tissues.

What's in a mate? Social pairing decisions and spatial cognitive ability in food-caching mountain chickadees.

While researchers have investigated mating decisions for decades, gaps remain in our understanding of how behaviour influences social mate choice. We compared spatial cognitive performance and food caching propensity within social pairs of mountain chickadees inhabiting differentially harsh winter climates to understand how these measures contribute to social mate choice. Chickadees rely on specialized spatial cognitive abilities to recover food stores and survive harsh winters, and females can discriminate among males with varying spatial cognition.

Activation of the integrated stress response by inhibitors of its kinases.

Phosphorylation of the translation initiation factor eIF2α to initiate the integrated stress response (ISR) is a vital signalling event. Protein kinases activating the ISR, including PERK and GCN2, have attracted considerable attention for drug development. Here we find that the widely used ATP-competitive inhibitors of PERK, GSK2656157, GSK2606414 and AMG44, inhibit PERK in the nanomolar range, but surprisingly activate the ISR via GCN2 at micromolar concentrations.

Food-caching chickadees with specialized spatial cognition do not use scrounging as a stable strategy when learning a spatial task.

Social animals may use alternative strategies when foraging, with producer-scrounger being one stable dichotomy of strategies. While 'producers' search and discover new food sources, 'scroungers' obtain food discovered by producers. Previous work suggests that differences in cognitive abilities may influence tendencies toward being either a producer or a scrounger, but scrounging behaviour in the context of specialized cognitive abilities is less understood.

Complex relationships between climate and reproduction in a resident montane bird.

Animals use climate-related environmental cues to fine-tune breeding timing and investment to match peak food availability. In birds, spring temperature is a commonly documented cue used to initiate breeding, but with global climate change, organisms are experiencing both directional changes in ambient temperatures and extreme year-to-year precipitation fluctuations. Montane environments exhibit complex climate patterns where temperatures and precipitation change along elevational gradients, and where exacerbated annual variation in precipitation has resulted in extreme swings between heavy snow and drought.

An Overview of Methods for Detecting eIF2α Phosphorylation and the Integrated Stress Response.

Phosphorylation of the translation initiation factor eIF2α is an adaptive signaling event that is essential for cell and organismal survival from yeast to humans. It is central to the integrated stress response (ISR) that maintains cellular homeostasis in the face of threats ranging from viral infection, amino acid, oxygen, and heme deprivation to the accumulation of misfolded proteins in the endoplasmic reticulum. Phosphorylation of eIF2α has broad physiological, pathological, and therapeutic relevance.

Molecular Investigation of the Unfolded Protein Response in Select Human Tauopathies.

Background: Tauopathies are a group of neurodegenerative diseases associated with the accumulation of misfolded tau protein. The mechanisms underpinning tau-dependent proteinopathy remain to be elucidated. A protein quality control pathway within the endoplasmic reticulum, the unfolded protein response (UPR), has been suggested as a possible pathway modulating cellular responses in a range of neurodegenerative diseases, including those associated with misfolded cytosolic tau.

Social dominance has limited effects on spatial cognition in a wild food-caching bird.

Social dominance has long been used as a model to investigate social stress. However, many studies using such comparisons have been performed in captive environments. These environments may produce unnaturally high antagonistic interactions, exaggerating the stress of social subordination and any associated adverse consequences.

The genetic basis of spatial cognitive variation in a food-caching bird.

Spatial cognition is used by most organisms to navigate their environment. Some species rely particularly heavily on specialized spatial cognition to survive, suggesting that a heritable component of cognition may be under natural selection. This idea remains largely untested outside of humans, perhaps because cognition in general is known to be strongly affected by learning and experience.

Food discovery is associated with different reliance on social learning and lower cognitive flexibility across environments in a food-caching bird.

Social learning is a primary mechanism for information acquisition in social species. Despite many benefits, social learning may be disadvantageous when independent learning is more efficient. For example, searching independently may be more advantageous when food sources are ephemeral and unpredictable.

Specialized spatial cognition is associated with reduced cognitive senescence in a food-caching bird.

Senescence, the gradual reduction and loss of function as organisms age, is a widespread process that is especially pronounced in cognitive abilities. Senescence appears to have a genetic basis and can be affected by evolutionary processes. If cognitive senescence is shaped by natural selection, it may be linked with selection on cognitive abilities needed for survival and reproduction, such that species where fitness is directly related to cognitive abilities should evolve delayed cognitive senescence likely resulting in higher lifetime fitness.

Testing the greater male variability phenomenon: male mountain chickadees exhibit larger variation in reversal learning performance compared with females.

The greater male variability phenomenon predicts that males exhibit larger ranges of variation in cognitive performance compared with females; however, support for this pattern has come exclusively from studies of humans and lacks mechanistic explanation. Furthermore, the vast majority of the literature assessing sex differences in cognition is based on studies of humans and a few other mammals. In order to elucidate the underpinnings of cognitive variation and the potential for fitness consequences, we must investigate sex differences in cognition in non-mammalian systems as well.

A primate-specific short GluN2A-NMDA receptor isoform is expressed in the human brain.

Glutamate receptors of the N-methyl-D-aspartate (NMDA) family are coincident detectors of pre- and postsynaptic activity, allowing Ca influx into neurons. These properties are central to neurological disease mechanisms and are proposed to be the basis of associative learning and memory. In addition to the well-characterised canonical GluN2A NMDAR isoform, large-scale open reading frames in human tissues had suggested the expression of a primate-specific short GluN2A isoform referred to as GluN2A-S.

Smart is the new sexy: female mountain chickadees increase reproductive investment when mated to males with better spatial cognition.

Understanding the evolution of inter and intraspecific variation in cognitive abilities is one of the main goals in cognitive ecology. In scatter-caching species, spatial memory is critical for the recovery of food caches and overwinter survival, but its effects on reproduction are less clear. Better spatial cognition may improve pre-breeding condition allowing for earlier reproduction.

Natural Selection and Spatial Cognition in Wild Food-Caching Mountain Chickadees.

Understanding how differences in cognition evolve is one of the critical goals in cognitive ecology [1-5]. In food-caching species that rely on memory to recover caches, enhanced spatial cognition has been hypothesized to evolve via natural selection [2, 6-8], but there has been no direct evidence of natural selection acting on spatial memory. Food-caching mountain chickadees living at harsher, higher elevations, with greater reliance on cached food have better spatial learning abilities and larger hippocampi containing more and larger neurons compared to birds from milder, lower elevations [9, 10].

Minimalistic in vitro systems for investigating tau pathology.

Neurofibrillary tangles, formed of hyperphosphorylated, misfolded tau accumulations, are a pathological hallmark of neurodegenerative diseases such as Alzheimer's disease (AD) and frontotemporal dementia. The neuroanatomical localisation of tau pathology in AD brains of different disease stages suggests that tau tangle pathology is spreading throughout the brain along connected neuronal circuits. Pathogenic tau can act as a prion-like seed, inducing the misfolding of native tau and leading to disease propagation throughout the brain.

Correction to: 'Fluctuations in annual climatic extremes are associated with reproductive variation in resident mountain chickadees'.

[This corrects the article DOI: 10.1098/rsos.171604.

Fluctuations in annual climatic extremes are associated with reproductive variation in resident mountain chickadees.

Mounting evidence suggests that we are experiencing rapidly accelerating global climate change. Understanding how climate change may affect life is critical to identifying species and populations that are vulnerable. Most current research focuses on investigating how organisms may respond to gradual warming, but another effect of climate change is extreme annual variation in precipitation associated with alternations between drought and unusually heavy precipitation, like that exhibited in the western regions of North America.