Brain, Behavior and Evolution

INTRODUCTION: The octopus peduncle complex is an agglomeration of neural structures with remarkably diverse functional roles. The complex rests on the optic tract, between the optic lobe and the central brain, and comprises the peduncle lobe proper, the olfactory lobe, and the optic gland. The peduncle lobe regulates visuomotor behaviors, the optic glands control sexual maturation and maternal death, and the olfactory lobe is thought to receive input from the olfactory organ. Recent transcriptomic and metabolomic studies have identified candidate peptide and steroid ligands in the Octopus bimaculoides optic gland...

Introduction Pythons are a well-studied model of postprandial physiological plasticity. Consuming a meal evokes a suite of physiological changes in pythons including one of the largest documented increases in post-feeding metabolic rates relative to resting values. However, little is known about how this plasticity manifests in the brain. Previous work has shown that cell proliferation in the python brain increases six days following meal consumption. This study aimed to confirm these findings and build on them in the long term by tracking the survival and maturation of these newly created cells across a two-month period...

No abstract text is available yet for this article.

INTRODUCTION: Transitions in temporal niche have occurred many times over the course of mammalian evolution. These are associated with changes in sensory stimuli available to animals, particularly with visual cues, because levels of light are so much higher during the day than night. This relationship between temporal niche and available sensory stimuli elicits the expectation that evolutionary transitions between diurnal and nocturnal lifestyles will be accompanied by modifications of sensory systems that optimize the ability of animals to receive, process, and react to important stimuli in the environment...

INTRODUCTION: The gray short-tailed opossum, Monodelhis domestica (M. domestica) is a widely used marsupial model species that presents unique advantages for neurodevelopmental studies. Notably their extremely altricial birth allows manipulation of postnatal pups at timepoints equivalent to embryonic stages of placental mammals. A robust literature exists on the development of short-tailed opossums, but many researchers working in the more conventional model species of mice and rats may find it daunting to identify the appropriate age at which to conduct experiments...

BACKGROUND: By examining species-specific innate behaviours, neuroethologists have characterised unique neural strategies and specializations from throughout the animal kingdom. Simultaneously, the field of evolutionary developmental biology (informally, "evo-devo") seeks to make inferences about animals' evolutionary histories through careful comparison of developmental processes between species, because evolution is the evolution of development. Yet despite the shared focus on cross-species comparisons, there is surprisingly little cross-talk between these two fields...

INTRODUCTION: The changes in knee axial rotation plays an important role in traumatic and non-traumatic knee disorders. It is known that support afferentation can affect the axial rotator muscles. The condition of innervation of the ST and BFp has changed in non terrestrial and terrestrial vertebrates in evolution, thus we hypothesized this situation might be replayed by hindlimb unloading (HU). METHODS: In the present study the EMG activity of two hamstring muscles, m...

Introduction Neural exaptations represent descent via transitions to novel neural functions. A primary transition in human cognitive and neural evolution was from a predominantly socially-oriented primate brain to a brain that also instantiates and subserves science, and technology, and engineering, all of which depend on mathematics. Upon what neural substrates, and upon what evolved cognitive mechanisms, did human capacities for STEM, and especially its mathematical underpinnings, emerge? Previous theory focuses on roles for tools, language, and arithmetic in the cognitive origins of STEM, but none of these factors appears sufficient to support the transition...

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)...

Felids have evolved a specialized suite of morphological adaptations for obligate carnivory. Although the musculoskeletal anatomy of the Felidae has been studied extensively, the comparative neuroanatomy of felids is relatively unexplored. Little is known about how variation in cerebral anatomy of felids relates to species-specific differences in sociality, hunting strategy, or activity patterns. We quantitatively analyzed neuropil variation in the prefrontal, primary motor, and primary visual cortices of six species of Felidae (Panthera leo, Panthera uncia, Panthera tigris, Panthera Leopardus, Acinonyx jubatus, Felis sylvestris domesticus) to investigate relationships with brain size, neuronal cell parameters, and select behavioral and ecological factors...

The phylotypic or intermediate stages are thought to be the most evolutionary conserved stages throughout embryonic development. The contrast with divergent early and later stages derived in the concept of the evo-devo hourglass model. Nonetheless, this developmental constraint has been studied as a whole embryo process, not at organ level. In this review, we explore brain development to assess the existence of an equivalent brain developmental hourglass. In the specific case of vertebrates, we propose to split the brain developmental stages into: 1) Early: Neurulation, when the neural tube arises after gastrulation...

INTRODUCTION: The study of non-laboratory species has been part of a broader effort to establish the basic organization of the mammalian neocortex, as these species may provide unique insights relevant to cortical organization, function, and evolution. METHODS: In the present study, the organization of three somatosensory cortical areas of the medium-sized (5-11 kg body mass) Amazonian rodent, the paca (Cuniculus paca), was determined using a combination of electrophysiological microelectrode mapping and histochemical techniques (Cytochrome oxidase and NADPH diaphorase) in tangential sections...

TThe present study demonstrates that in the same brain area the astroglia can express GFAP (the main cytoskeletal protein of astroglia) in some species but not in the others of the same vertebrate class. It contrasts the former opinions that the distribution of GFAP found in a species is characteristic of the entire class. The present study investigated birds in different phylogenetic positions: duck (Cairina moschata domestica), chicken (Gallus gallus domesticus), and quails (Coturnix japonica and Excalfactoria chinensis) of Galloanserae; pigeon (Columba livia domestica) of a group of Neoaves, in comparison to representatives of other Neoaves lineages, which emerged more recently in evolution: finches (Taeniopygia guttata and Erythrura gouldiae), magpie (Pica pica), and parrots (Melopsittacus undulatus and Nymphicus hollandicus)...

BACKGROUND: Several evolutionary explanations have been proposed for why chronic pain is a major clinical problem. One is that some mechanisms important for driving chronic pain, while maladaptive for modern humans, were adaptive because they enhanced survival. Evidence is reviewed for persistent nociceptor hyperactivity (PNH), known to promote chronic pain in rodents and humans, being an evolutionarily adaptive response to significant bodily injury, and primitive molecular mechanisms related to cellular injury and stress being exapted (co-opted or repurposed) to drive PNH and consequent pain...

Shared selection pressures often explain convergent trait loss, yet anurans (frogs and toads) have lost their middle ears at least 38 times with no obvious shared selection pressures unifying 'earless' taxa. Anuran tympanic middle ear loss is especially perplexing because acoustic communication is dominant within Anura and tympanic middle ears enhance airborne hearing in most tetrapods. Here we examine whether particular geographic ranges, microhabitats, activity patterns, or aspects of acoustic communication are associated with anuran tympanic middle ear loss...

No abstract text is available yet for this article.

Uncovering relationships between neuroanatomy, behavior, and evolution is important for understanding the factors that control brain function. Voluntary exercise is one key behavior that both affects, and may be affected by, neuroanatomical variation. Moreover, recent studies suggest an important role for physical activity in brain evolution. We used a unique and ongoing artificial selection model in which mice are bred for high voluntary wheel-running behavior, yielding four replicate lines of High Runner (HR) mice that run ~3-fold more revolutions per day than four replicate non-selected Control (C) lines...

The song circuit in passerine birds is an outstanding model system for understanding the relationship between brain morphology and behavior, in part due to varying degrees of sex differences in structure and function across species. House wrens (Troglodytes aedon) offer a unique opportunity to advance our understanding of this relationship. Intermediate sex differences in song rate and complexity exist in this species compared to other passerines, and, among individual females, song complexity varies dramatically...

The comparative approach is a powerful way to explore the relationship between brain structure and cognitive function. Thus far the field has been dominated by the assumption that a bigger brain somehow means better cognition. Correlations between differences in brain size or neuron number between species and differences in specific cognitive abilities exist, but these correlations are very noisy. Extreme differences exist between clades in the relationship between either brain size or neuron number and specific cognitive abilities...

As the highest center of sensory processing, initiation and modulation of behaviour, the pallium has seen prominent changes during the course of vertebrate evolution, culminating in the emergence of the mammalian isocortex. The processes underlying this remarkable evolution have been a matter of debate for several centuries. Recent studies using modern techniques in a host of vertebrate species are beginning to reveal mechanistic principles underlying pallial evolution from the developmental, connectome, transcriptome, and cell type levels...