Avian telencephalon and cerebellum volumes can be accurately estimated from digital brain endocasts.

For studies of the evolution of vertebrate brain anatomy and potentially associated behaviours, reconstructions of digital brain endocasts from computed tomography scans have revolutionized our capacity to collect neuroanatomical data. However, measurements from digital endocasts must be validated as reflecting actual brain anatomy, which is difficult because the collection of soft tissue information through histology is laborious and time-consuming. In birds, the reliability of digital endocast measurements as volume proxies for the two largest brain regions-the telencephalon and cerebellum-remains to be validated despite their use as proxies, e.

The quantitative anatomy of the hippocampal formation in homing pigeons and other pigeon breeds: implications for spatial cognition.

Artificial selection for specific behavioural and physical traits in domesticated animals has resulted in a wide variety of breeds. One of the most widely recognized examples of behavioural selection is the homing pigeon (Columba livia), which has undergone intense selection for fast and efficient navigation, likely resulting in significant anatomical changes to the hippocampal formation. Previous neuroanatomical comparisons between homing and other pigeon breeds yielded mixed results, but only focused on volumes.

The 44th Annual Meeting of the J.B. Johnston Club for Evolutionary Neuroscience and the 36th Annual Karger Workshop in Evolutionary Neuroscience.

N/A.

Quality not quantity: Deficient juvenile play experiences lead to altered medial prefrontal cortex neurons and sociocognitive skill deficits.

Reduced play experience over the juvenile period leads to adults with impoverished social skills and to anatomical and physiological aberrations of the neurons found in the medial prefrontal cortex (mPFC). Even rearing rats from high-playing strains with low-playing strains show these developmental consequences. In the present study, we evaluated whether low-playing rats benefit from being reared with higher playing peers.

A Comparison of Telencephalon Composition among Chickens, Junglefowl, and Wild Galliforms.

Introduction: Domestication is the process of modifying animals for human benefit through selective breeding in captivity. One of the traits that often diverges is the size of the brain and its constituent regions; almost all domesticated species have relatively smaller brains and brain regions than their wild ancestors. Although the effects of domestication on the brain have been investigated across a range of both mammal and bird species, almost nothing is known about the neuroanatomical effects of domestication on the world's most common bird: the chicken (Gallus gallus).

Online repositories of photographs and videos provide insights into the evolution of skilled hindlimb movements in birds.

The ability to manipulate objects with limbs has evolved repeatedly among land tetrapods. Several selective forces have been proposed to explain the emergence of forelimb manipulation, however, work has been largely restricted to mammals, which prevents the testing of evolutionary hypotheses in a comprehensive evolutionary framework. In birds, forelimbs have gained the exclusive function of flight, with grasping transferred predominantly to the beak.

Neutrophils in Health and Disease: From Receptor Sensing to Inflammasome Activation.

Neutrophils-polymorphonuclear cells (PMNs) are the cells of the initial immune response and make up the majority of leukocytes in the peripheral blood. After activation, these cells modify their functional status to meet the needs at the site of action or according to the agent causing injury. They receive signals from their surroundings and "plan" the course of the response in both temporal and spatial contexts.

Comparative Analysis of the Temporal Impacts of Corticosterone and Simulated Production Stressors on the Metabolome of Broiler Chickens.

The impact of physiological stress on the metabolome of breast muscle, liver, kidney, and hippocampus was investigated in Ross 308 broiler chicks. Simulated on-farm stressors were compared to a corticosterone model of physiological stress. The three different stressors investigated were: (i) corticosterone at a dose of 15 mg/kg of feed; (ii) heat treatment of 36 °C and 40% RH for 8 h per day; and (iii) isolation for 1 h per day.

The relative sizes of nuclei in the oculomotor complex vary by order and behaviour in birds.

Eye movements are a critical component of visually guided behaviours, allowing organisms to scan the environment and bring stimuli of interest to regions of acuity in the retina. Although the control and modulation of eye movements by cranial nerve nuclei are highly conserved across vertebrates, species variation in visually guided behaviour and eye morphology could lead to variation in the size of oculomotor nuclei. Here, we test for differences in the size and neuron numbers of the oculomotor nuclei among birds that vary in behaviour and eye morphology.

Atypical play experiences in the juvenile period has an impact on the development of the medial prefrontal cortex in both male and female rats.

In rats reared without play, or with limited access to play during the juvenile period, the dendrites of pyramidal neurons of the medial prefrontal cortex (mPFC) exhibit more branching than rats reared with more typical levels of play. This suggests that play is critical for pruning the dendritic arbor of these neurons. However, the rearing paradigms typically used to limit play involve physical separation from a peer or sharing a cage with an adult, causing stress that may disrupt pruning.

The promoting effect of neutrophil-derived BAFF molecule on the proliferation and life span of CAL-27 oral squamous carcinoma cells.

Tumor-associated neutrophils (TANs) are the major cellular component of the tumor microenvironment and have been shown to release of different bioactive molecules such as B-cell activating factor (BAFF). The data on the interactions between OSCC cells and neutrophils are limited and do not explain the actual role of the BAFF in the development of the OSCC. In the present study we examined the direct effect of neutrophils-derived BAFF on the OSCC cell line CAL-27 proliferation and apoptosis.

Seasonal differences in the morphology and spine density of hippocampal neurons in wild ground squirrels.

Seasonally reproducing small mammals often undergo changes in brain anatomy throughout the year. Much of the research on this seasonal neuroplasticity has focused on changes in hippocampus volume and neurogenesis, with relatively little attention paid to neuronal morphology. Here, we test for sex, season and sex-season interaction effects on hippocampal neuron morphology and dendritic spine density in a seasonally reproducing rodent: Richardson's ground squirrel (Urocitellus richardsonii).

Not like night and day: the nocturnal letter-winged kite does not differ from diurnal congeners in orbit or endocast morphology.

Nocturnal birds display diverse adaptations of the visual system to low-light conditions. The skulls of birds reflect many of these and are used increasingly to infer nocturnality in extinct species. However, it is unclear how reliable such assessments are, particularly in cases of recent evolutionary transitions to nocturnality.

Coevolution of relative brain size and life expectancy in parrots.

Previous studies have demonstrated a correlation between longevity and brain size in a variety of taxa. Little research has been devoted to understanding this link in parrots; yet parrots are well-known for both their exceptionally long lives and cognitive complexity. We employed a large-scale comparative analysis that investigated the influence of brain size and life-history variables on longevity in parrots.

The cerebellar anatomy of red junglefowl and white leghorn chickens: insights into the effects of domestication on the cerebellum.

Domestication is the process by which wild organisms become adapted for human use. Many phenotypic changes are associated with animal domestication, including decreases in brain and brain region sizes. In contrast with this general pattern, the chicken has a larger cerebellum compared with the wild red junglefowl, but what neuroanatomical changes are responsible for this difference have yet to be investigated.

A quantitative analysis of cerebellar anatomy in birds.

The cerebellum is largely conserved in its circuitry, but varies greatly in size and shape across species. The extent to which differences in cerebellar morphology is driven by changes in neuron numbers, neuron sizes or both, remains largely unknown. To determine how species variation in cerebellum size and shape is reflective of neuron sizes and numbers requires the development of a suitable comparative data set and one that can effectively separate different neuronal populations.

The evolution of mammalian brain size.

Relative brain size has long been considered a reflection of cognitive capacities and has played a fundamental role in developing core theories in the life sciences. Yet, the notion that relative brain size validly represents selection on brain size relies on the untested assumptions that brain-body allometry is restrained to a stable scaling relationship across species and that any deviation from this slope is due to selection on brain size. Using the largest fossil and extant dataset yet assembled, we find that shifts in allometric slope underpin major transitions in mammalian evolution and are often primarily characterized by marked changes in body size.

Endocast structures are reliable proxies for the sizes of corresponding regions of the brain in extant birds.

Endocasts are increasingly relied upon to examine avian brain evolution because they can be used across extant and extinct species. The endocasts of birds appear to be relatively faithful representatives of the external morphology of their brains, but it is unclear how well the size of a surface feature visible on endocasts reflects the volume of the underlying brain region. The optic lobe and the Wulst are two endocast structures that are clearly visible on the external surface of avian endocasts.

Selection for Divergent Reproductive Investment Affects Neuron Size and Foliation in the Cerebellum.

The cerebellum has a highly conserved internal circuitry, but varies greatly in size and morphology within and across species. Despite this variation, the underlying volumetric changes among the layers of the cerebellar cortex or their association with Purkinje cell numbers and sizes is poorly understood. Here, we examine intraspecific scaling relationships and variation in the quantitative neuroanatomy of the cerebellum in Japanese quail (Coturnix japonica) selected for high or low reproductive investment.

Allometric Scaling Rules of the Cerebellum in Galliform Birds.

Although the internal circuitry of the cerebellum is highly conserved across vertebrate species, the size and shape of the cerebellum varies considerably. Recent comparative studies have examined the allometric rules between cerebellar mass and number of neurons, but data are lacking on the numbers and sizes of Purkinje and granule cells or scaling of cerebellar foliation. Here, we investigate the allometric rules that govern variation in the volumes of the layers of the cerebellum, the numbers and sizes of Purkinje cells and granule cells and the degree of the cerebellar foliation across 7 species of galliform birds.

Author Correction: The endocast of the Night Parrot (Pezoporus occidentalis) reveals insights into its sensory ecology and the evolution of nocturnality in birds.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The endocast of the Night Parrot (Pezoporus occidentalis) reveals insights into its sensory ecology and the evolution of nocturnality in birds.

The Night Parrot (Pezoporus occidentalis) is a rare, nocturnal parrot species that has largely escaped scientific investigation due to its behaviour and habitat preferences. Recent field studies have revealed some insights into Night Parrot behaviour, but nothing is known of its sensory abilities. Here, we used μCT scans of an intact Night Parrot specimen to determine if its visual system shares similarities with other nocturnal species.

Zebrin Expression in the Cerebellum of Two Crocodilian Species.

While in birds and mammals the cerebellum is a highly convoluted structure that consists of numerous transverse lobules, in most amphibians and reptiles it consists of only a single unfolded sheet. Orthogonal to the lobules, the cerebellum is comprised of sagittal zones that are revealed in the pattern of afferent inputs, the projection patterns of Purkinje cells, and Purkinje cell response properties, among other features. The expression of several molecular markers, such as aldolase C, is also parasagittally organized.

Sensory systems in birds: What we have learned from studying sensory specialists.

"Diversity" is an apt descriptor of the research career of Jack Pettigrew as it ranged from the study of trees, to clinical conditions, to sensory neuroscience. Within sensory neuroscience, he was fascinated by the evolution of sensory systems across species. Here, we review some of his work on avian sensory specialists and research that he inspired in others.