Correlations between Major Brain Regions in Chiroptera

Pirlot, Paul; Jolicœur, Pierre

doi:10.1159/000121589

Cited by 40 publications

(13 citation statements)

References 5 publications

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“…We also showed that phylogenetic constraints may act on the morphology of closely related species to a certain extent, making the use of independent contrasts a useful tool to reveal such effects. Previous studies on encephalization and brain regions in bats (and other mammals) found an influence of diet on brain size (Eisenberg & Wilson 1978;Pirlot & Jolicoeur 1982;Jolicoeur et al 1984;Harvey & Krebs 1990;Barton et al 1995;Hutcheon et al 2002). It has been speculated that it is not the nature of the food of animal taxa which directly influences brain size, but rather the variation in information storage and retrieval systems associated with diet (Eisenberg & Wilson 1978;Harvey & Krebs 1990).…”

Section: Discussionmentioning

confidence: 99%

Adaptation of brain regions to habitat complexity: a comparative analysis in bats (Chiroptera)

2005

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Vertebrate brains are organized in modules which process information from sensory inputs selectively. Therefore they are probably under different evolutionary pressures. We investigated the impact of environmental influences on specific brain centres in bats. We showed in a phylogenetically independent contrast analysis that the wing area of a species corrected for body size correlated with estimates of habitat complexity. We subsequently compared wing area, as an indirect measure of habitat complexity, with the size of regions associated with hearing, olfaction and spatial memory, while controlling for phylogeny and body mass. The inferior colliculi, the largest sub-cortical auditory centre, showed a strong positive correlation with wing area in echolocating bats. The size of the main olfactory bulb did not increase with wing area, suggesting that the need for olfaction may not increase during the localization of food and orientation in denser habitat. As expected, a larger wing area was linked to a larger hippocampus in all bats. Our results suggest that morphological adaptations related to flight and neuronal capabilities as reflected by the sizes of brain regions coevolved under similar ecological pressures. Thus, habitat complexity presumably influenced and shaped sensory abilities in this mammalian order independently of each other.

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Section: Discussionmentioning

confidence: 99%

Adaptation of brain regions to habitat complexity: a comparative analysis in bats (Chiroptera)

2005

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“…It has been proposed that the relatively small brains of planktivorous predators were related to their opportunistic passive predation strategies [Nilsson et al, 2000], which might be less cognitively demanding in terms of sensory and/or motor requirements in comparison to more agile hunters [Kruska, 1988;Ito et al, 1999;Nilsson et al, 2000;. Diet, foraging strategies, and strategic hunting have been linked to brain size [reviewed by Striedter, 2005] in various vertebrate groups, such as teleosts [Bauchot et al, 1977;Kotrschal et al, 1998], birds [Bennet and Harvey, 1985;Lefebvre et al, 1997;Hunt et al, 2001], and mammals [Eisenberg and Wilson, 1978;Clutton-Brock and Harvey, 1980;Pirlot and Jolicoeur, 1982;Bennet and Harvey, 1985;Harvey and Krebs, 1990;Hutcheon et al, 2002]. An exception has been noted, however, in the planktivorous mobulids, species that have the most encephalized brains of all chondrichthyans [Striedter, 2005;K.…”

Section: Encephalizationmentioning

confidence: 99%

Brain Size and Brain Organization of the Whale Shark, <i>Rhincodon typus</i>, Using Magnetic Resonance Imaging

Yopak

Frank²

2009

Brain Behav Evol

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Very little is known about the brain organization of the suction filter feeder, Rhincodon typus, and how it compares to other orectolobiforms in light of its specialization as a plankton-feeder. Brain size and overall brain organization was assessed in two specimens of R. typus in relation to both phylogeny and ecology, using magnetic resonance imaging (MRI). In comparison to over 60 other chondrichthyan species, R. typus demonstrated a relatively small brain for its body size (expressed in terms of encephalization quotients and residuals), similar to the lamniforms Carcharodon carcharias, Cetorhinus maximus, and Carcharias taurus. R. typus possessed a relatively small telencephalon with some development of the dorsal pallium, which was suggestive of moderate social behavior, in addition to a relatively large diencephalon and a relatively reduced mesencephalon. The most notable characteristic of the brain of Rhincodon was a large and highly foliated cerebellum, one of the largest cerebellums within the chondrichthyan clade. Early development of the brain was qualitatively assessed using an in situ MRI scan of the brain and chondrocranium of a neonate specimen of R. typus. There was evidence that folding of the cerebellar corpus appeared in early development, although the depth and number of folds might vary ontogenetically in this species. Hierarchical cluster analysis and multidimensional scaling ordinations showed evidence of convergent evolution with the basking shark, Cetorhinus maximus, another large-bodied filter feeding elasmobranch, supporting the claim that organization of the brain is more similar in species with analogous but independently evolved lifestyles than those that share taxonomic classification.

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“…Allometric analyses of the relationship of animal behavior and lifestyle have long hoped to find close relationships between lifestyle variables, such as frugivory, method of locomotion or social organization, and constellations of changes in sizes of brain components [Pirlot and Jolicoeur, 1982;Armstrong, 1987;Stephan and Frahm, 1988;Gittleman, 1991Gittleman, , 1994Gittleman, , 1995Aboitiz, 1996;Barton, 1996]. It is fair to say that these efforts have met with only modest success.…”

Section: Subcomponent Structure In Brain Enlargement: the Limbic Systemmentioning

confidence: 99%

Patterns of Vertebrate Neurogenesis and the Paths of Vertebrate Evolution

Finlay

Hersman²,

Darlington³

1998

Brain Behav Evol

103

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Any substantial change in brain size requires a change in the number of neurons and their supporting elements in the brain, which in turn requires an alteration in either the rate, or the duration of neurogenesis. The schedule of neurogenesis is surprisingly stable in mammalian brains, and increases in the duration of neurogenesis have predictable outcomes: late-generated structures become disproportionately large. The olfactory bulb and associated limbic structures may deviate in some species from this general brain enlargement: in the rhesus monkey, reduction of limbic system size appears to be produced by an advance in the onset of terminal neurogenesis in limbic system structures. Not only neurogenesis but also many other features of neural maturation such as process extension and retraction, follow the same schedule with the same predictability. Although the underlying order of event onset remains the same for all of the mammals we have yet studied, changes in overall rate of neural maturation distinguish related subclasses, such as marsupial and placental mammals, and changes in duration of neurodevelopment distinguish species within subclasses. A substantial part of the regularity of event sequence in neurogenesis can be related directly to the two dimensions of the neuraxis in a recently proposed prosomeric segmentation of the forebrain [Rubenstein et al., Science, 266: 578, 1994]. Both the spatial and temporal organization of development have been highly conserved in mammalian brain evolution, showing strong constraint on the types of brain adaptations possible. The neural mechanisms for integrative behaviors may become localized to those locations that have enough plasticity in neuron number to support them.

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Correlations between Major Brain Regions in Chiroptera

Cited by 40 publications

References 5 publications

Adaptation of brain regions to habitat complexity: a comparative analysis in bats (Chiroptera)

Adaptation of brain regions to habitat complexity: a comparative analysis in bats (Chiroptera)

Brain Size and Brain Organization of the Whale Shark, <i>Rhincodon typus</i>, Using Magnetic Resonance Imaging

Patterns of Vertebrate Neurogenesis and the Paths of Vertebrate Evolution

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