Exceptionally Steep Brain-Body Evolutionary Allometry Underlies the Unique Encephalization of Osteoglossiformes
Brain-body static allometry, which is the relationship between brain size and body size within species, is thought to reflect developmental and genetic constraints. Existing evidence suggests that the evolution of large brain size without accompanying changes in body size (that is, encephalization) may occur when this constraint is relaxed. Teleost fish species are generally characterized by having close-fitting brain-body static allometries, leading to strong allometric constraints and small relative brain sizes. However, one order of teleost, Osteoglossiformes, underwent extreme encephalization, and its mechanistic bases...
Source: Brain, Behavior and Evolution - October 11, 2021 Category: Neurology Source Type: research
Analysis of the Expression Pattern of Cajal-Retzius Cell Markers in the < b > < i > Xenopus laevis < /i > < /b > Forebrain
Cajal-Retzius cells are essential for cortical development in mammals, and their involvement in the evolution of this structure has been widely postulated, but very little is known about their progenitor domains in non-mammalian vertebrates. Using in situhybridization and immunofluorescence techniques we analyzed the expression of some of the main Cajal-Retzius cell markers such as Dbx1, Ebf3, ER81, Lhx1, Lhx5, p73, Reelin, Wnt3a, Zic1, and Zic2 in the forebrain of the anuranXenopus laevis, because amphibians are the only class of anamniote tetrapods and show a tetrapartite evaginated pallium, but no layered or nuclear org...
Source: Brain, Behavior and Evolution - October 6, 2021 Category: Neurology Source Type: research
Time in Neurogenesis: Conservation of the Developmental Formation of the Cerebellar Circuitry
The cerebellum is a conserved structure of vertebrate brains that develops at the most anterior region of the alar rhombencephalon. All vertebrates display a cerebellum, making it one of the most highly conserved structures of the brain. Although it greatly varies at the morphological level, several lines of research point to strong conservation of its internal neural circuitry. To test the conservation of the cerebellar circuit, we compared the developmental history of the neurons comprising this circuit in three amniote species: mouse, chick, and gecko. We specifically researched the developmental time of generation of t...
Source: Brain, Behavior and Evolution - September 30, 2021 Category: Neurology Source Type: research
Forebrain Architecture and Development in Cyclostomes, with Reference to the Early Morphology and Evolution of the Vertebrate Head
The vertebrate head and brain are characterized by highly complex morphological patterns. The forebrain, the most anterior division of the brain, is subdivided into the diencephalon, hypothalamus, and telencephalon from the neuromeric subdivision into prosomeres. Importantly, the telencephalon contains the cerebral cortex, which plays a key role in higher order cognitive functions in humans. To elucidate the evolution of the forebrain regionalization, comparative analyses of the brain development between extant jawed and jawless vertebrates are crucial. Cyclostomes – lampreys and hagfishes – are the only extant jawless...
Source: Brain, Behavior and Evolution - September 17, 2021 Category: Neurology Source Type: research
A Relationship between the Characteristics of the Oval Nucleus of the Mesopallium and Parrot Vocal Response to Playback
Correlations between differences in animal behavior and brain structures have been used to infer function of those structures. Brain region size has especially been suggested to be important for an animal ’s behavioral capability, controlled by specific brain regions. The oval nucleus of the mesopallium (MO) is part of the anterior forebrain vocal learning pathway in the parrot brain. Here, we compare brain volume and total number of neurons in MO of three parrot species (the peach-fronted conure,Eupsittula aurea, the peach-faced lovebird,Agapornis roseicollis, and the budgerigar,Melopsittacus undulatus), relating the to...
Source: Brain, Behavior and Evolution - July 20, 2021 Category: Neurology Source Type: research
Tyramine 1 Receptor Distribution in the Brain of Corbiculate Bees Points to a Conserved Function
Sucrose represents an important carbohydrate source for most bee species. In the Western honeybee (Apis mellifera) it was shown that individual sucrose responsiveness correlates with the task performed in the colony, supporting the response threshold theory which states that individuals with the lowest threshold for a task-associated stimuli will perform the associated task. Tyramine was shown to modulate sucrose responsiveness, most likely via the tyramine 1 receptor. This receptor is located in brain areas important for the processing of gustatory stimuli. We asked whether the spatial expression pattern of the tyramine 1...
Source: Brain, Behavior and Evolution - July 15, 2021 Category: Neurology Source Type: research
Contents Vol. 95, 2020
Brain Behav Evol 2020;95:I –IV (Source: Brain, Behavior and Evolution)
Source: Brain, Behavior and Evolution - July 9, 2021 Category: Neurology Source Type: research
Acknowledgement to Reviewers
Brain Behav Evol 2020;95:341 (Source: Brain, Behavior and Evolution)
Source: Brain, Behavior and Evolution - July 9, 2021 Category: Neurology Source Type: research
A Farewell to the Encephalization Quotient: A New Brain Size Measure for Comparative Primate Cognition
Both absolute and relative brain sizes vary greatly among and within the major vertebrate lineages. Scientists have long debated how larger brains in primates and hominins translate into greater cognitive performance, and in particular how to control for the relationship between the noncognitive functions of the brain and body size. One solution to this problem is to establish the slope of cognitive equivalence, i.e., the line connecting organisms with an identical bauplan but different body sizes. The original approach to estimate this slope through intraspecific regressions was abandoned after it became clear that it gen...
Source: Brain, Behavior and Evolution - July 9, 2021 Category: Neurology Source Type: research
The Lamprey Forebrain – Evolutionary Implications
The forebrain plays a critical role in a broad range of neural processes encompassing sensory integration and initiation/selection of behaviour. The forebrain functions through an interaction between different cortical areas, the thalamus, the basal ganglia with the dopamine system, and the habenulae. The ambition here is to compare the mammalian forebrain with that of the lamprey representing the oldest now living group of vertebrates, by a review of earlier studies. We show that the lamprey dorsal pallium has a motor, a somatosensory, and a visual area with retinotopic representation. The lamprey pallium was previously t...
Source: Brain, Behavior and Evolution - June 30, 2021 Category: Neurology Source Type: research
The Paracingulate Sulcus Is a Unique Feature of the Medial Frontal Cortex Shared by Great Apes and Humans
Primate brains display a wide range of variation in size and cerebral gyrification, leading to the appearance of novel sulci in particular groups of species. We investigated sulcal organization in the medial frontal cortex of great apes, with a particular focus on the paracingulate sulcus (PCGS). Until recently, the presence of the PCGS was thought to be a structural feature unique to the human brain. However, upon closer examination, the PCGS has been observed as a variable feature that also may appear in chimpanzee brains. To understand the evolutionary origins of the sulcal anatomy in the medial frontal cortex of apes, ...
Source: Brain, Behavior and Evolution - June 30, 2021 Category: Neurology Source Type: research
Author Index/Subject Index
Brain Behav Evol 2020;95:286 (Source: Brain, Behavior and Evolution)
Source: Brain, Behavior and Evolution - June 28, 2021 Category: Neurology Source Type: research
Preliminaries
Brain Behav Evol 2020;95:213 –215 (Source: Brain, Behavior and Evolution)
Source: Brain, Behavior and Evolution - June 28, 2021 Category: Neurology Source Type: research
The Independent Evolution of Dorsal Pallia in Multiple Vertebrate Lineages
Comparative neurobiologists have long wondered when and how the dorsal pallium (e.g., mammalian neocortex) evolved. For the last 50 years, the most widely accepted answer has been that this structure was already present in the earliest vertebrates and, therefore, homologous between the major vertebrate lineages. One challenge for this hypothesis is that the olfactory bulbs project throughout most of the pallium in the most basal vertebrate lineages (notably lampreys, hagfishes, and lungfishes) but do not project to the putative dorsal pallia in teleosts, cartilaginous fishes, and amniotes (i.e., reptiles, birds, and mammal...
Source: Brain, Behavior and Evolution - June 25, 2021 Category: Neurology Source Type: research
Ontogeny of Inner Ear Saccular Development in the Plainfin Midshipman ( < b > < i > Porichthys notatus < /i > < /b > )
The auditory system of the plainfin midshipman fish (Porichthys notatus) is an important sensory system used to detect and encode biologically relevant acoustic stimuli important for survival and reproduction including social acoustic signals used for intraspecific communication. Previous work showed that hair cell (HC) density in the midshipman saccule increased seasonally with reproductive state and was concurrent with enhanced auditory saccular sensitivity in both females and type I males. Although reproductive state-dependent changes in HC density have been well characterized in the adult midshipman saccule, less is kn...
Source: Brain, Behavior and Evolution - June 23, 2021 Category: Neurology Source Type: research
