Neurogenetic heterochrony in chick, lizard and rat mapped with wholemount AChE and the prosomeric model.
In the developing brain, the phenomenon of neurogenesis is manifested heterotopically, that is, much the same neurogenetic steps occur at different places with a different timetable. This is due apparently to early molecular regionalization of the neural tube wall in the anteroposterior and dorsoventral dimensions, in a checkerboard pattern of more or less deformed quadrangular histogenetic areas. Their respective fate is apparently specified by a locally specific combination of active/repressed genes known as ‘molecular profile’. This leads to position-dependent differential control of proliferation, neurogenesis, dif...
Source: Brain, Behavior and Evolution - March 23, 2022 Category: Neurology Source Type: research
Relative brain volume of carnivorans has evolved in correlation with environmental and dietary variables differentially among clades
Carnivorans possess relatively large brains compared to most other mammalian clades. Factors like environmental complexity (Cognitive Buffer Hypothesis) and diet quality (Expensive-Tissue Hypothesis) have been proposed as mechanisms for encephalization in other large-brained clades. We examine whether the Cognitive Buffer and Expensive-Tissue Hypotheses account for brain size variation within Carnivora. Under these hypotheses, we predict a positive correlation between brain size and environmental complexity or protein consumption. Relative endocranial volume (PGLS residual from species mean body mass) and nine environmenta...
Source: Brain, Behavior and Evolution - March 2, 2022 Category: Neurology Source Type: research
Luis Puelles, the learned neuroembryologist and comparative neurobiologist
NA (Source: Brain, Behavior and Evolution)
Source: Brain, Behavior and Evolution - February 28, 2022 Category: Neurology Source Type: research
Role of melatonin in temperature-induced activation of the neuroendocrine reproductive axis in garter snakes.
An animal ’s ability to respond optimally to changing environmental conditions is paramount to successfully reproducing and thus maximizing fitness. Studies on photoperiod-induced changes in neural thyroid hormone metabolism have conclusively linked environmental cues to the neuroendocrine reproductive axis of birds and mammals. Whether this conserved mechanism also transduces changes in environmental temperature, however, has not been fully addressed. We investigated whether the hormone melatonin mediates the effects of low temperature winter dormancy on thyroid hormone metabolism within the hypothal amus of red-sided g...
Source: Brain, Behavior and Evolution - February 25, 2022 Category: Neurology Source Type: research
Color discrimination provides insight into the relationship between personality cognition and brain morphology in the of western mosquitofish ’s (Gambusia affinis)
Recent studies on the differences in cognitive ability between individuals focused on two aspects: one is whether the individual differences in cognitive ability are related to brain size, the other is whether they pertain to certain personality traits. To explore these two hypotheses, we tested the personality traits, cognitive abilities and brain volumes of western mosquitofish (Gambusia affinis). First, a color preference test was conducted to select two unbiased colors for G. affinis for subsequent cognitive tests. The results showed that G. affinis had a great preference for red and green to yellow and blue, therefore...
Source: Brain, Behavior and Evolution - February 21, 2022 Category: Neurology Source Type: research
The tempo of mammalian embryogenesis: variation in the pace of brain and body development
Why do some species develop rapidly, while others develop slowly? Mammals are highly variable in the pace of growth and development over every stage of ontogeny, and this basic variable – the pace of ontogeny – is strongly associated with a wide range of phenotypes in adults, including allometric patterns of brain and body size as well as the pace of neurodevelopment. This analysis describes variation in the pace of embryonic development in eutherian mammals, drawing on a colle cted dataset of embryogenesis in fifteen species representing rodents, carnivores, ungulates, and primates. Mammals vary in the pace of every s...
Source: Brain, Behavior and Evolution - February 21, 2022 Category: Neurology Source Type: research
Peripheral auditory system divergence does not explain species differences in call preference
In this study, we extend prior work characterizing the lack of correlated evolution between auditory tuning and spectral properties of male calls in Engystomops (= Physalaemus) frogs. We analyze auditory sensitivity of three cryptic species that differ consistently in female mate preferences for calls of different frequencies. The audiograms of these species differ, but the frequency at which the frog is maximally sensitive is not the most relevant difference in tuning of the auditory periphery. Rather, we identify species differences in overall sensitivity within specific frequency ranges, and we model the effects of thes...
Source: Brain, Behavior and Evolution - February 11, 2022 Category: Neurology Source Type: research
Phenotypic alterations in cortical organization and connectivity across different time scales
In the following review, we describe the types of phenotypic changes to the neocortex that occur over the longer time scale of evolution, and over the shorter time scale of an individual lifetime. To understand how phenotypic variability emerges in the neocortex, it is important to consider the cortex as part of an integrated system of the brain, the body, the environment in which the brain and body develops and evolves, and the affordances available within a particular environmental context; changes in any part of this brain/body/environment network impacts the neocortex. We provide data from comparative studies on a wide...
Source: Brain, Behavior and Evolution - February 3, 2022 Category: Neurology Source Type: research
Vocal communication in hummingbirds
Hummingbirds exhibit complex vocal repertoires that they use in their social interactions. Furthermore, they are capable of vocal production learning, an ability they share with songbirds, parrots, some non-oscine birds, and some mammals including humans. Despite these characteristics, hummingbirds have not received the same attention as other birds, especially songbirds and parrots in the study of vocal communication. Recent studies are advancing our knowledge of vocal communication in hummingbirds showing that these birds exhibit complex social learning and extraordinary abilities for vocal production. Moreover, vocal pr...
Source: Brain, Behavior and Evolution - January 24, 2022 Category: Neurology Source Type: research
Multi-level effects driving cognitive and behavioral variability among prairie voles: Insights into reproductive decision-making from biological levels of organization
Behavioral phenotypes play an active role in maximizing fitness and shaping the evolutionary trajectory of species by offsetting the ecological and social environmental factors individuals experience. How these phenotypes evolve and how they are expressed is still a major question in ethology today. In recent years, an increased focus on the mechanisms that regulate the interactions between an individual and its environment has offered novel insights into the expression of alternative phenotypes. In this review, we explore the proximate mechanisms driving the expression of alternative reproductive phenotypes in the male pr...
Source: Brain, Behavior and Evolution - January 20, 2022 Category: Neurology Source Type: research
Ecology, Cognition, and the Hippocampus: A Tale of Two Frogs
The underlying hypothesis that motivates research into the relationship between ecology, cognition, and the hippocampus is that selection to solve problems in nature shapes cognition through changes in the hippocampus. This hypothesis has been explored almost exclusively in mammals and birds. However, if one is interested in the principles that shape the evolution of vertebrate cognition, work in amphibians is essential. To address this gap, we have developed a research program contrasting cognitive abilities and hippocampal neurobiology in two species of frog with distinct social and spatial ecologies. We have found that ...
Source: Brain, Behavior and Evolution - January 20, 2022 Category: Neurology Source Type: research
Ecology, Cognition and the Hippocampus: A Tale of Two Frogs
The underlying hypothesis that motivates research into the relationship between ecology, cognition, and the hippocampus is that selection to solve problems in nature shapes cognition through changes in the hippocampus. This hypothesis has been explored almost exclusively in mammals and birds. However, if one is interested in the principles that shape the evolution of vertebrate cognition, work in amphibians is essential. To address this gap, we have developed a research program contrasting cognitive abilities and hippocampal neurobiology in two species of frog with distinct social and spatial ecologies. We have found that ...
Source: Brain, Behavior and Evolution - January 20, 2022 Category: Neurology Source Type: research
The multiple contexts of brain scaling:
Phenotypic integration in brain and behavioral evolution
Understanding the adaptive functions of increasing brain size have occupied scientists for decades. Here, taking the general perspective of the Extended Evolutionary Synthesis, the question of how brains change in size will be considered in two developmental frameworks. The first framework will consider the particular developmental mechanisms that control and generate brain mass, concentrating on neurogenesis in a comparative vertebrate context. The consequences of limited adult neurogenesis in mammals, and the dominating role of duration of neurogenesis for mammalian evolution will be discussed for the particular case of ...
Source: Brain, Behavior and Evolution - January 14, 2022 Category: Neurology Source Type: research
Is there a prechordal region and an acroterminal domain in amphioxus?
This essay re-examines the singular case of the supposedly unique rostrally elongated notochord described classically in amphioxus. We start from our previous observations in hpf 21 larvae [Albuixech-Crespo et al., 2017] indicating that the brain vesicle has rostrally a rather standard hypothalamic molecular configuration. This correlates with the notochord across a possible rostromedian acroterminal hypothalamic domain . The notochord shows some molecular differences that specifically characterize its pre-acroterminal extension beyond its normal rostral end under the mamillary region. We explored an alternative interpreta...
Source: Brain, Behavior and Evolution - January 14, 2022 Category: Neurology Source Type: research
A smaller habenula is associated with increasing intensity of sexual selection
The habenula is a small structure in the brain that acts as a relay station for neural information, helping to modulate behaviour in response to variable and unpredictable stimuli. Broadly, it is evolutionarily conserved in structure and connectivity across vertebrates, and is the most prominent bilaterally asymmetric structure in the brain. Nonetheless, comparative evolutionary studies of the habenula are virtually nonexistent. Here, we examine the volumes of the medial and lateral habenular subregions, in both hemispheres, across a group of Australian agamid lizards in the genus Ctenophorus. In males, we found bilaterall...
Source: Brain, Behavior and Evolution - January 4, 2022 Category: Neurology Source Type: research
