Linking Colony Size with Foraging Behavior and Brain Investment in Odorous Ants (Formicidae: Dolichoderinae)
In this study, we control for environmental differences and worker size polymorphism to test if colony size correlates with measures of foraging behavior and brain size in dolichoderine ants. We present data from 3 species ranked by colony size. Our results suggest colony size correlates with measures of exploratory behavior and brain investment, with small-colony ants showing higher exploratory drive and faster exploration rate than the larger colony species, and greater relative investment in the primary olfactory brain region, the antennal lobe, than the larger colony species.Brain Behav Evol 2020;95:15 –24 (Source: B...
Source: Brain, Behavior and Evolution - December 20, 2019 Category: Neurology Source Type: research
Jaw Elevator Muscle Coordination during Rhythmic Mastication in Primates: Are Triplets Units of Motor Control?
The activity of mammal jaw elevator muscles during chewing has often been described using the concept of the triplet motor pattern, in which triplet I (balancing side superficial masseter and medial pterygoid; working side posterior temporalis) is consistently activated before triplet II (working side superficial masseter and medial pterygoid; balancing side posterior temporalis), and each triplet of muscles is recruited and modulated as a unit. Here, new measures of unison, synchrony, and coordination are used to determine whether in 5 primate species (Propithecus verreauxi,Eulemur fulvus,Papio anubis,Macaca fuscata,andPa...
Source: Brain, Behavior and Evolution - December 10, 2019 Category: Neurology Source Type: research
Neuroethology Meets < b > < i > Brain, Behavior and Evolution < /i > < /b > : Promoting the Study of the Neural Basis of Behavior
Brain Behav Evol 2019;94:5 –6 (Source: Brain, Behavior and Evolution)
Source: Brain, Behavior and Evolution - December 6, 2019 Category: Neurology Source Type: research
Field Homology: Still a Meaningless Concept
Brain Behav Evol 2019;93:1 –3 (Source: Brain, Behavior and Evolution)
Source: Brain, Behavior and Evolution - June 14, 2019 Category: Neurology Source Type: research
Immunocytochemical Evidence for Electrical Synapses in the Dorsal Descending and Dorsal Anterior Octaval Nuclei in the Goldfish, < b > < i > Carassius auratus < /i > < /b >
The dorsal portion of the descending octaval nucleus (dDO), the main first-order auditory nucleus in jawed fish, includes four lateral and three medial neuronal populations that project to the auditory midbrain. One medial population and one lateral population contain neurons that receive a remarkably large axon terminal from the utricular branch of the octaval nerve. Immunocytochemistry for connexin 35 (Cx35) was used to determine whether this connection includes electrical synapses. Although Cx35 was not localized to these large contacts, it was observed in the three other lateral dDO populations. Another first-order nuc...
Source: Brain, Behavior and Evolution - June 12, 2019 Category: Neurology Source Type: research
Contents Vol. 92, 2018
Brain Behav Evol 2018;92:I –II (Source: Brain, Behavior and Evolution)
Source: Brain, Behavior and Evolution - May 5, 2019 Category: Neurology Source Type: research
Brain Connectivity in < b > < i > Ateles geoffroyi < /i > < /b > : Resting-State Functional Magnetic Resonance Imaging of Working Memory and Executive Control
The objective of this research was to describe the organization and connectivity of the working memory (WM) and executive control (EC) networks inAteles geoffroyi in resting-state conditions. Recent studies have shown that resting-state activity may underlie rudimentary brain functioning, showing that several brain regions can be tonically active at rest, maximizing the efficiency of information transfer while preserving a low physical connection cost. Whole-brain resting-state images were acquired from three healthy adultAteles monkeys (2 females, 1 male; mean age 10.5 ± SD 2.5 years). Data were analyzed with independent...
Source: Brain, Behavior and Evolution - May 5, 2019 Category: Neurology Source Type: research
Social Complexity and Brain Evolution: Comparative Analysis of Modularity and Integration in Ant Brain Organization
The behavioral demands of living in social groups have been linked to the evolution of brain size and structure, but how social organization shapes investment and connectivity within and among functionally specialized brain regions remains unclear. To understand the influence of sociality on brain evolution in ants, a premier clade of eusocial insects, we statistically analyzed patterns of brain region size covariation as a proxy for brain region connectivity. We investigated brain structure covariance in young and old workers of two formicine ants, the Australasian weaver antOecophylla smaragdina, a pinnacle of social com...
Source: Brain, Behavior and Evolution - April 15, 2019 Category: Neurology Source Type: research
Brain Changes during Phyletic Dwarfing in Elephants and Hippos
Of all known insular mammals, hippos and elephants present the extremes of body size decrease, reducing to 4 and a mere 2% of their ancestral mainland size, respectively. Despite the numerous studies on these taxa, what happens to their relative brain size during phyletic dwarfing is not well known, and results are sometimes conflicting. For example, relative brain size increase has been noted in the Sicilian dwarf elephant,Palaeoloxodon falconeri, whereas relative brain size decrease has been postulated for Malagasy dwarf hippos. Here, I perform an analysis of brain, skull, and body size of 3 insular elephants (Palaeoloxo...
Source: Brain, Behavior and Evolution - April 3, 2019 Category: Neurology Source Type: research
Thalamic Reticular Nucleus in < b > < i > Caiman crocodilus < /i > < /b > : Immunohistochemical Staining
The thalamic reticular nucleus in reptiles,Caiman crocodilus, shares a number of morphological similarities with its counterpart in mammals. In view of the immunohistochemical properties of this nucleus in mammals and the more recently identified complexity of this neuronal aggregate inCaiman, this nucleus was investigated using a number of antibodies. These results were compared with findings described for other amniotes. The following antibodies gave consistent and reproducible results: polyclonal sheep anti-parvalbumin (PV), monoclonal mouse anti-PV, and polyclonal sheep anti-glutamic acid decarboxylase (GAD). In the tr...
Source: Brain, Behavior and Evolution - March 14, 2019 Category: Neurology Source Type: research
Sensory Specializations of Mormyrid Fish Are Associated with Species Differences in Electric Signal Localization Behavior
The ability to localize communication signals plays a fundamental role in social interactions. For signal localization to take place, the sensory system of the receiver must extract information about distance and direction to the sender from physical characteristics of the signal. In many sensory systems, information from multiple peripheral receptors must be integrated by central sensory pathways to determine the sender location. Here, we asked whether evolutionary divergence in the electrosensory and visual systems of mormyrid fish is associated with signal localization behavior. In mormyrids, differences in the distribu...
Source: Brain, Behavior and Evolution - March 7, 2019 Category: Neurology Source Type: research
Eye Optics in Semiaquatic Mammals for Aerial and Aquatic Vision
Based on anatomical measurements of refractive structures in the eye, the positions of focused images were computed for several groups of semiaquatic mammals: rodents, a nonpinniped semiaquatic carnivore (the sea otter), and pinniped carnivores (seals, sea lions, and the walrus). In semiaquatic rodents, eye optics enable emmetropia in the air but cause substantial hypermetropia in the water. In semiaquatic carnivores, there are several mechanisms for amphibious vision that focus images on the retina in both air and water. These mechanisms include the potential for a substantial change in the lens shape of sea otters and th...
Source: Brain, Behavior and Evolution - February 21, 2019 Category: Neurology Source Type: research
Erratum
Brain Behav Evol (Source: Brain, Behavior and Evolution)
Source: Brain, Behavior and Evolution - January 28, 2019 Category: Neurology Source Type: research
Retinal Topography in Two Species of Baleen Whale (Cetacea: Mysticeti)
In this study, we investigate eye morphology and the topographic distribution of retinal ganglion cells (RGCs) in two species of mysticete, Bryde ’s whale (Balaenoptera edeni) and the humpback whale (Megaptera novaeanglia). Both species have large eyes characterised by a thickened cornea, a heavily thickened sclera, a highly vascularised fibro-adipose bundle surrounding the optic nerve at the back of the eye, and a reflective blue-green tapetum fibrosum. Using stereology and retinal whole mounts, we estimate a total of 274,268 and 161,371 RGCs in the Bryde ’s whale and humpback whale retinas, respectively. Both species...
Source: Brain, Behavior and Evolution - January 27, 2019 Category: Neurology Source Type: research
Brain and Body Size Relations among Spotted Hyenas ( < b > < i > Crocuta crocuta < /i > < /b > )
The relationship between brain size and body size across species “from mouse to elephant” is described by a function of positive slope. Almost uniformly, the relationship between brain size and body size within a species has a positive slope, though this is less steep than across species. The spotted hyena,Crocuta crocuta, differs from most other mammals in a number of ways including the fact that, on average, adult females weigh more than adult males and occasionally display greater body lengths. Brains of 5 female and 4 male hyenas were weighed in the field near Moyale in Northern Kenya, and body weights and body len...
Source: Brain, Behavior and Evolution - November 9, 2018 Category: Neurology Source Type: research
