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Laforest K, Peele E, Yopak K. Ontogenetic Shifts in Brain Size and Brain Organization of the Atlantic Sharpnose Shark, Rhizoprionodon terraenovae. BRAIN, BEHAVIOR AND EVOLUTION 2020; 95:162-180. [DOI: 10.1159/000511304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/31/2020] [Indexed: 11/19/2022]
Abstract
Throughout an animal’s life, species may occupy different environments and exhibit distinct life stages, known as ontogenetic shifts. The life histories of most sharks (class: Chondrichthyes) are characterized by these ontogenetic shifts, which can be defined by changes in habitat and diet as well as behavioral changes at the onset of sexual maturity. In addition, fishes experience indeterminate growth, whereby the brain and body grow throughout the organism’s life. Despite a presupposed lifelong neurogenesis in sharks, very little work has been done on ontogenetic changes in the brain, which may be informative about functional shifts in sensory and behavioral specializations. This study quantified changes in brain-body scaling and the scaling of six major brain regions (olfactory bulbs, telencephalon, diencephalon, optic tectum, cerebellum, and medulla oblongata) throughout ontogeny in the Atlantic sharpnose shark, <i>Rhizoprionodon terraenovae</i>. As documented in other fishes, brain size increased significantly with body mass throughout ontogeny in this species, with the steepest period of growth in early life. The telencephalon, diencephalon, optic tectum, and medulla oblongata scaled with negative allometry against the rest of the brain throughout ontogeny. However, notably, the olfactory bulbs and cerebellum scaled hyperallometrically to the rest of the brain, whereby these structures enlarged disproportionately as this species matured. Changes in the relative size of the olfactory bulbs throughout ontogeny may reflect an increased reliance on olfaction at later life history stages in <i>R. terraenovae</i>, while changes in the relative size of the cerebellum throughout ontogeny may be indicative of the ability to capture faster prey or an increase in migratory nature as this species moves to offshore habitats, associated with the onset of sexual maturity.
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Shukla V, Rani S, Malik S, Kumar V, Sadananda M. Neuromorphometric changes associated with photostimulated migratory phenotype in the Palaearctic-Indian male redheaded bunting. Exp Brain Res 2020; 238:2245-2256. [PMID: 32719907 DOI: 10.1007/s00221-020-05888-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 07/20/2020] [Indexed: 12/18/2022]
Abstract
Neural substrates, including brain areas, differential gene expression and neuroendocrine basis, of migration are known. However, very little is known about structural changes in the brain that underlie the development and cessation of migration in long-distance avian migrants. Towards this, we investigated neuromorphological changes in the higher-order associative areas in male redheaded bunting (Emberiza bruniceps), which is a Palaearctic-Indian night migrant with wintering grounds in India. Photosensitive birds (8L:16D; SD) were exposed to stimulatory long days (16L:8D; LD), with controls retained on non-stimulatory short days. LD birds depicted shifts to, and sustained night-time activity as recorded by actograms. LD birds demonstrated increased body mass, fat deposition and testicular volume in keeping with the migratory phenotype. When LD birds had exhibited 10.0 ± 2.4 cycles of Zugunruhe (intense nighttime activity in captives, akin to night migratory flight in the wild), bird brains were fixed by transcardial perfusion, and changes in the neuronal morphometry of pallial, sub-pallial and hypothalamic brain regions studied using rapid Golgi technique with modifications, as used and validated in our laboratory. There were significant differences in both area and perimeter of soma in the visual hyperpallium apicale implicated in migratory orientation and the neuroendocrine control region for timing of migration, the mediobasal hypothalamus. We attribute these neuromorphometric changes in the soma area and perimeter to the photostimulated changes associated with the development of migration and reproductive phenotypes in redheaded buntings. It is suggested that changes in the neuronal plasticity in brain control regions parallel photoperiod-induced physiological responses.
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Affiliation(s)
- Vidya Shukla
- Brain Research Laboratory, Biotechnology Unit, Department of Biosciences, Mangalore University, Mangalagangothri, 574199, Karnataka, India
| | - Sangeeta Rani
- Department of Zoology, University of Lucknow, Lucknow, 226007, India
| | - Shalie Malik
- Department of Zoology, University of Lucknow, Lucknow, 226007, India
| | - Vinod Kumar
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Monika Sadananda
- Brain Research Laboratory, Biotechnology Unit, Department of Biosciences, Mangalore University, Mangalagangothri, 574199, Karnataka, India.
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Knoll F, Kawabe S. Avian palaeoneurology: Reflections on the eve of its 200th anniversary. J Anat 2020; 236:965-979. [PMID: 31999834 DOI: 10.1111/joa.13160] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 12/28/2019] [Accepted: 01/07/2020] [Indexed: 12/13/2022] Open
Abstract
In birds, the brain (especially the telencephalon) is remarkably developed, both in relative volume and complexity. Unlike in most early-branching sauropsids, the adults of birds and other archosaurs have a well-ossified neurocranium. In contrast to the situation in most of their reptilian relatives but similar to what can be seen in mammals, the brains of birds fit closely to the endocranial cavity so that their major external features are reflected in the endocasts. This makes birds a highly suitable group for palaeoneurological investigations. The first observation about the brain in a long-extinct bird was made in the first quarter of the 19th century. However, it was not until the 2000s and the application of modern imaging technologies that avian palaeoneurology really took off. Understanding how the mode of life is reflected in the external morphology of the brains of birds is but one of several future directions in which avian palaeoneurological research may extend. Although the number of fossil specimens suitable for palaeoneurological explorations is considerably smaller in birds than in mammals and will very likely remain so, the coming years will certainly witness a momentous strengthening of this rapidly growing field of research at the overlap between ornithology, palaeontology, evolutionary biology and neurosciences.
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Affiliation(s)
- Fabien Knoll
- ARAID-Fundación Conjunto Paleontológico de Teruel-Dinópolis, Teruel, Spain.,Departamento de Paleobiología, Museo Nacional de Ciencias Naturales-CSIC, Madrid, Spain
| | - Soichiro Kawabe
- Institute of Dinosaur Research, Fukui Prefectural University, Fukui, Japan.,Fukui Prefectural Dinosaur Museum, Fukui, Japan
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Coppola VJ, Bingman VP. Aging is associated with larger brain mass and volume in homing pigeons (Columba livia). Neurosci Lett 2019; 698:39-43. [DOI: 10.1016/j.neulet.2019.01.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 12/28/2018] [Accepted: 01/03/2019] [Indexed: 01/21/2023]
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Lugo Ramos JS, Delmore KE, Liedvogel M. Candidate genes for migration do not distinguish migratory and non-migratory birds. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 203:383-397. [PMID: 28585043 PMCID: PMC5522501 DOI: 10.1007/s00359-017-1184-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 05/12/2017] [Accepted: 05/15/2017] [Indexed: 10/27/2022]
Abstract
Migratory traits in birds have been shown to have a strong heritable component and several candidate genes have been suggested to control these migratory traits. To investigate if the genetic makeup of one or a set of these candidate genes can be used to identify a general pattern between migratory and non-migratory birds, we extracted genomic sequence data for 25 hypothesised candidate genes for migration from 70 available genomes across all orders of Aves and characterised sequence divergence between migratory and non-migratory phenotypes. When examining each gene separately across all species, we did not identify any genetic variants in candidate genes that distinguished migrants from non-migrants; any resulting pattern was driven by the phylogenetic signal. This was true for each gene analysed independently, but also for concatenated sequence alignments of all candidate genes combined. We also attempted to distinguish between migrant and non-migrants using structural features at four candidate genes that have previously been reported to show associated with migratory behaviour but did not pick up a signal for migratory phenotype here either. Finally, a screen for dN/dS ratio across all focal candidate genes to probe for putative features of selection did not uncover a pattern, though this might not be expected given the broad phylogenetic scale used here. Our study demonstrates the potential of public genomic data to test for general patterns of migratory gene candidates in a cross-species comparative context, and raise questions on the applicability of candidate gene approaches in a macro-evolutionary context to understand the genetic architecture of migratory behaviour.
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Affiliation(s)
- Juan S Lugo Ramos
- Max Planck Institute for Evolutionary Biology, AG Behavioural Genomics, August-Thienemann-Str. 2, 24306, Plön, Germany
| | - Kira E Delmore
- Max Planck Institute for Evolutionary Biology, AG Behavioural Genomics, August-Thienemann-Str. 2, 24306, Plön, Germany
| | - Miriam Liedvogel
- Max Planck Institute for Evolutionary Biology, AG Behavioural Genomics, August-Thienemann-Str. 2, 24306, Plön, Germany.
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Vincze O, Vágási CI, Pap PL, Osváth G, Møller AP. Brain regions associated with visual cues are important for bird migration. Biol Lett 2016; 11:rsbl.2015.0678. [PMID: 26538538 DOI: 10.1098/rsbl.2015.0678] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Long-distance migratory birds have relatively smaller brains than short-distance migrants or residents. Here, we test whether reduction in brain size with migration distance can be generalized across the different brain regions suggested to play key roles in orientation during migration. Based on 152 bird species, belonging to 61 avian families from six continents, we show that the sizes of both the telencephalon and the whole brain decrease, and the relative size of the optic lobe increases, while cerebellum size does not change with increasing migration distance. Body mass, whole brain size, optic lobe size and wing aspect ratio together account for a remarkable 46% of interspecific variation in average migration distance across bird species. These results indicate that visual acuity might be a primary neural adaptation to the ecological challenge of migration.
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Affiliation(s)
- Orsolya Vincze
- MTA-DE 'Lendület' Behavioural Ecology Research Group, Department of Evolutionary Zoology and Human Biology, University of Debrecen, Egytem tér 1, 4032, Debrecen, Hungary Evolutionary Ecology Group, Hungarian Department of Biology and Ecology, Babeş-Bolyai University, Clinicilor Street 5-7, 400006, Cluj-Napoca, Romania
| | - Csongor I Vágási
- MTA-DE 'Lendület' Behavioural Ecology Research Group, Department of Evolutionary Zoology and Human Biology, University of Debrecen, Egytem tér 1, 4032, Debrecen, Hungary Evolutionary Ecology Group, Hungarian Department of Biology and Ecology, Babeş-Bolyai University, Clinicilor Street 5-7, 400006, Cluj-Napoca, Romania
| | - Péter L Pap
- MTA-DE 'Lendület' Behavioural Ecology Research Group, Department of Evolutionary Zoology and Human Biology, University of Debrecen, Egytem tér 1, 4032, Debrecen, Hungary Evolutionary Ecology Group, Hungarian Department of Biology and Ecology, Babeş-Bolyai University, Clinicilor Street 5-7, 400006, Cluj-Napoca, Romania
| | - Gergely Osváth
- MTA-DE 'Lendület' Behavioural Ecology Research Group, Department of Evolutionary Zoology and Human Biology, University of Debrecen, Egytem tér 1, 4032, Debrecen, Hungary Evolutionary Ecology Group, Hungarian Department of Biology and Ecology, Babeş-Bolyai University, Clinicilor Street 5-7, 400006, Cluj-Napoca, Romania Museum of Zoology, Babeş-Bolyai University, Clinicilor Street 5-7, 400006, Cluj-Napoca, Romania
| | - Anders Pape Møller
- Laboratoire d'Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-Sud, Bâtiment 362, 91405 Orsay Cedex, France
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Vincze O. Light enough to travel or wise enough to stay? Brain size evolution and migratory behavior in birds. Evolution 2016; 70:2123-33. [DOI: 10.1111/evo.13012] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Revised: 07/11/2016] [Accepted: 07/14/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Orsolya Vincze
- MTA-DE “Lendület” Behavioural Ecology Research Group, Department of Evolutionary Zoology and Human Biology; University of Debrecen; Debrecen H-4032 Hungary
- Evolutionary Ecology Group, Hungarian Department of Biology and Ecology; Babeş-Bolyai University; Cluj-Napoca 400006 Romania
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Sayol F, Lefebvre L, Sol D. Relative Brain Size and Its Relation with the Associative Pallium in Birds. BRAIN, BEHAVIOR AND EVOLUTION 2016; 87:69-77. [DOI: 10.1159/000444670] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 02/11/2016] [Indexed: 11/19/2022]
Abstract
Despite growing interest in the evolution of enlarged brains, the biological significance of brain size variation remains controversial. Much of the controversy is over the extent to which brain structures have evolved independently of each other (mosaic evolution) or in a coordinated way (concerted evolution). If larger brains have evolved by the increase of different brain regions in different species, it follows that comparisons of the whole brain might be biologically meaningless. Such an argument has been used to criticize comparative attempts to explain the existing variation in whole-brain size among species. Here, we show that pallium areas associated with domain-general cognition represent a large fraction of the entire brain, are disproportionally larger in large-brained birds and accurately predict variation in the whole brain when allometric effects are appropriately accounted for. While this does not question the importance of mosaic evolution, it suggests that examining specialized, small areas of the brain is not very helpful for understanding why some birds have evolved such large brains. Instead, the size of the whole brain reflects consistent variation in associative pallium areas and hence is functionally meaningful for comparative analyses.
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Brain contrasts between migratory and nonmigratory North American lark sparrows (Chondestes grammacus). Neuroreport 2015; 26:1011-6. [DOI: 10.1097/wnr.0000000000000460] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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