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Ross MD, Hargey AS, Smyth LK, Mann GK, O'Riain MJ. New Records of White Phenotype Honey Badgers (Mellivora capensis) from South Africa. AFRICAN JOURNAL OF WILDLIFE RESEARCH 2022. [DOI: 10.3957/056.052.0012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
| | | | | | | | - M. Justin O'Riain
- iCWild, Department of Biological Sciences, University of Cape Town, Cape Town, South Africa
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2
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Huynh M, Piazza S. Musculoskeletal and Neurologic Diseases. FERRETS, RABBITS, AND RODENTS 2021. [PMCID: PMC7258713 DOI: 10.1016/b978-0-323-48435-0.00010-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ferrets may exhibit neurologic signs as a result of various conditions that may be of nervous or muscular origin. Neurologic examination follows the same principles as in small animal medicine. One of the main defect that may be screened during clinical examination is deafness. Congenital deafness in ferrets is associated with coat color patterns such as white markings and premature graying.In this species, paresis is a common presentation and may reflect a generalized weakness. Spinal disorder, intervertebral disk disease, and neoplasia are among the differential diagnosis. Diagnostic exams usually include advance diagnostic imaging such as CT-scan associated with myelography. Seizure is usually associated with hypoglycemia and insulinoma, but other causes such as hypocalcemia or intracranial disorders have been described. Ferrets are sensitive to various neurotropic infectious disease such as rabies, distemper, aleutian disease, or systemic coronavirus. Finally, muscular disorder such as disseminated idiopathic myofasciitis and myasthenia gravis have been recently described, and potential treatments have been intended.
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Landis MB, Candisani L, Munhoes LP, Gebin JCZ, Rezende F, Flores de Jesus MM, Medici EP, Ferraz KMPMDB. First record of albino lowland tapirs (Tapirus terrestris Linnaeus 1758) in an important Brazilian Atlantic Forest hotspot. MAMMALIA 2020. [DOI: 10.1515/mammalia-2019-0084] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Albinism is the absence of pigmentation or coloration and is rarely found in nature. In this study we examined photos and videos obtained by cameras traps in the Legado das Águas Reserve. In the images, we identified two albino lowland tapirs. The results highlight the necessity of understanding the genetic diversity of lowland tapir populations and the important role of the professional photography associated with scientific research.
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Affiliation(s)
- Mariana Bueno Landis
- Manacá Institute , Rodovia SP139, km 80, Caixa Postal 138, CEP 18230-000 , São Miguel Arcanjo , São Paulo , Brazil
- Wildlife Ecology , Management and Conservation Lab (LEMaC) , Forest Science Department , ESALQ , University of São Paulo , Av. Pádua Dias, 11 – Caixa Postal 09, 13418-900 , Piracicaba , São Paulo , Brazil
| | - Luciano Candisani
- International League of Conservation Photographers , Ilhabela , São Paulo , Brazil
| | - Leticia Prado Munhoes
- Manacá Institute , Rodovia SP139, km 80, Caixa Postal 138, CEP 18230-000 , São Miguel Arcanjo , São Paulo , Brazil
- Wildlife Ecology , Management and Conservation Lab (LEMaC) , Forest Science Department , ESALQ , University of São Paulo , Av. Pádua Dias, 11 – Caixa Postal 09, 13418-900 , Piracicaba , São Paulo , Brazil
| | - João Carlos Zecchini Gebin
- Manacá Institute , Rodovia SP139, km 80, Caixa Postal 138, CEP 18230-000 , São Miguel Arcanjo , São Paulo , Brazil
- Wildlife Ecology , Management and Conservation Lab (LEMaC) , Forest Science Department , ESALQ , University of São Paulo , Av. Pádua Dias, 11 – Caixa Postal 09, 13418-900 , Piracicaba , São Paulo , Brazil
| | | | | | - Emília Patrícia Medici
- Institute for Ecological Research , Caixa Postal 47, Nazaré Paulista, CEP:12960-000 , São Paulo , Brazil
| | - Katia Maria Paschoaletto Micchi de Barros Ferraz
- Manacá Institute , Rodovia SP139, km 80, Caixa Postal 138, CEP 18230-000 , São Miguel Arcanjo , São Paulo , Brazil
- Wildlife Ecology , Management and Conservation Lab (LEMaC) , Forest Science Department , ESALQ , University of São Paulo , Av. Pádua Dias, 11 – Caixa Postal 09, 13418-900 , Piracicaba , São Paulo , Brazil
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4
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Tavares MS, Aguiar LDS, Salvador CH, Galliez M. Beyond the color: the implications of pigmentation polymorphism in the activity behavior of a Neotropical squirrel. MAMMALIA 2020. [DOI: 10.1515/mammalia-2019-0025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractPigmentation polymorphism occurs in many mammals but is considered rare in natural populations. Here, we report the first record of pigmentation polymorphism in a Neotropical squirrel, Guerlinguetus ingrami, at a private reserve in southern Brazil. The number of records for leucistic squirrels was approximately half that for brown squirrels. We also tested the differences in activity patterns between the leucistic and the brown squirrels. Both phenotypes were diurnal, but there was temporal segregation between the two. Further studies are needed to elucidate the occurrence of leucism in G. ingrami, and the possible ecological and behavioral outcomes.
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Affiliation(s)
- Mariana Silva Tavares
- Departamento de Biologia e Biotecnologia, Instituto Federal do Rio de Janeiro, Rio de Janeiro, RJ 20270-021, Brazil
| | - Leonardo dos Santos Aguiar
- Departamento de Biologia e Biotecnologia, Instituto Federal do Rio de Janeiro, Rio de Janeiro, RJ 20270-021, Brazil
| | | | - Maron Galliez
- Departamento de Biologia e Biotecnologia, Instituto Federal do Rio de Janeiro, Rio de Janeiro, RJ 20270-021, Brazil
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A stranger in the family? On the social behavior of a leucistic collared peccary (Pecari tajacu) with pigmented conspecifics. Trop Ecol 2019. [DOI: 10.1007/s42965-019-00036-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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6
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Wood T, Moralejo D, Corry K, Snyder JM, Traudt C, Curtis C, Nance E, Parikh P, Juul SE. A Ferret Model of Encephalopathy of Prematurity. Dev Neurosci 2019; 40:475-489. [PMID: 31079096 PMCID: PMC6658350 DOI: 10.1159/000498968] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/18/2019] [Indexed: 12/14/2022] Open
Abstract
There is an ongoing need for relevant animal models in which to test therapeutic interventions for infants with neurological sequelae of prematurity. The ferret is an attractive model species as it has a gyrified brain with a white-to-gray matter ratio similar to that in the human brain. A model of encephalopathy of prematurity was developed in postnatal day 10 (P10) ferret kits, considered to be developmentally equivalent to infants of 24-26 weeks' gestation. Cross-fostered P10 ferret kits received 5 mg/kg of lipopolysaccharide (LPS) before undergoing consecutive hypoxia-hyperoxia-hypoxia (60 min at 9%, 120 min at 60%, and 30 min at 9%). Control animals received saline vehicle followed by normoxia. The development of basic reflexes (negative geotaxis, cliff aversion, and righting) as well as gait coordination on an automated catwalk were assessed between P28 and P70, followed by ex vivo magnetic resonance imaging (MRI) and immunohistochemical analysis. Compared to controls, injured animals had slower overall reflex development between P28 and P40, as well as smaller hind-paw areas consistent with "toe walking" at P42. Injured animals also displayed significantly greater lateral movement during CatWalk assessment as a result of reduced gait coordination. Ex vivo MRI showed widespread white-matter hyperintensity on T2-weighted imaging as well as altered connectivity patterns. This coincided with white-matter dysmaturation characterized by increased intensity of myelin basic protein staining, white-matter thinning, and loss of oligodendrocyte transcription factor 2 (OLIG2)-positive cells. These results suggest both pathological and motor deficits consistent with premature white-matter injury. This newborn ferret model can therefore provide an additional platform to assess potential therapies before translation to human clinical trials.
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Affiliation(s)
- Thomas Wood
- Division of Neonatology, Department of Pediatrics, University of Washington, Seattle, Washington, USA,
| | - Daniel Moralejo
- Division of Neonatology, Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Kylie Corry
- Division of Neonatology, Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Jessica M Snyder
- Department of Comparative Medicine, University of Washington, Seattle, Washington, USA
| | - Christopher Traudt
- Division of Neonatology, Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Chad Curtis
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
| | - Elizabeth Nance
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
| | - Pratik Parikh
- Division of Neonatology, Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Sandra E Juul
- Division of Neonatology, Department of Pediatrics, University of Washington, Seattle, Washington, USA
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7
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Lohse M, Bajo VM, King AJ. Development, organization and plasticity of auditory circuits: Lessons from a cherished colleague. Eur J Neurosci 2018; 49:990-1004. [PMID: 29804304 PMCID: PMC6519211 DOI: 10.1111/ejn.13979] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/11/2018] [Accepted: 05/23/2018] [Indexed: 12/20/2022]
Abstract
Ray Guillery was a neuroscientist known primarily for his ground-breaking studies on the development of the visual pathways and subsequently on the nature of thalamocortical processing loops. The legacy of his work, however, extends well beyond the visual system. Thanks to Ray Guillery's pioneering anatomical studies, the ferret has become a widely used animal model for investigating the development and plasticity of sensory processing. This includes our own work on the auditory system, where experiments in ferrets have revealed the role of sensory experience during development in shaping the neural circuits responsible for sound localization, as well as the capacity of the mature brain to adapt to changes in inputs resulting from hearing loss. Our research has also built on Ray Guillery's ideas about the possible functions of the massive descending projections that link sensory areas of the cerebral cortex to the thalamus and other subcortical targets, by demonstrating a role for corticothalamic feedback in the perception of complex sounds and for corticollicular projection neurons in learning to accommodate altered auditory spatial cues. Finally, his insights into the organization and functions of transthalamic corticocortical connections have inspired a raft of research, including by our own laboratory, which has attempted to identify how information flows through the thalamus.
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Affiliation(s)
- Michael Lohse
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Victoria M Bajo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Andrew J King
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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8
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Galante Rocha de Vasconcelos FT, Hauzman E, Dutra Henriques L, Kilpp Goulart PR, de Faria Galvão O, Sano RY, da Silva Souza G, Lynch Alfaro J, de Lima Silveira LC, Fix Ventura D, Oliveira Bonci DM. A novel nonsense mutation in the tyrosinase gene is related to the albinism in a capuchin monkey (Sapajus apella). BMC Genet 2017; 18:39. [PMID: 28476152 PMCID: PMC5420114 DOI: 10.1186/s12863-017-0504-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 04/12/2017] [Indexed: 11/27/2022] Open
Abstract
Background Oculocutaneous Albinism (OCA) is an autosomal recessive inherited condition that affects the pigmentation of eyes, hair and skin. The OCA phenotype may be caused by mutations in the tyrosinase gene (TYR), which expresses the tyrosinase enzyme and has an important role in the synthesis of melanin pigment. The aim of this study was to identify the genetic mutation responsible for the albinism in a captive capuchin monkey, and to describe the TYR gene of normal phenotype individuals. In addition, we identified the subject’s species. Results A homozygous nonsense mutation was identified in exon 1 of the TYR gene, with the substitution of a cytosine for a thymine nucleotide (C64T) at codon 22, leading to a premature stop codon (R22X) in the albino robust capuchin monkey. The albino and five non-albino robust capuchin monkeys were identified as Sapajus apella, based on phylogenetic analyses, pelage pattern and geographic provenance. One individual was identified as S. macrocephalus. Conclusion We conclude that the point mutation C64T in the TYR gene is responsible for the OCA1 albino phenotype in the capuchin monkey, classified as Sapajus apella. Electronic supplementary material The online version of this article (doi:10.1186/s12863-017-0504-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Felipe Tadeu Galante Rocha de Vasconcelos
- Departamento de Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, Av. Professor Mello Moraes 1721 Bloco A Sala D9 - Butantã, São Paulo, SP, Brazil, 05508-030
| | - Einat Hauzman
- Departamento de Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, Av. Professor Mello Moraes 1721 Bloco A Sala D9 - Butantã, São Paulo, SP, Brazil, 05508-030.,Instituto Israelita de Ensino e Pesquisa Albert Einstein, Hospital Israelita Albert Einstein, São Paulo, São Paulo, Brazil
| | - Leonardo Dutra Henriques
- Departamento de Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, Av. Professor Mello Moraes 1721 Bloco A Sala D9 - Butantã, São Paulo, SP, Brazil, 05508-030
| | - Paulo Roney Kilpp Goulart
- Núcleo de Teoria e Pesquisa do Comportamento, Universidade Federal do Pará, Rua Augusto Corrêa, 01 - Guamá, Belém, PA, Brazil, 66075-110
| | - Olavo de Faria Galvão
- Núcleo de Teoria e Pesquisa do Comportamento, Universidade Federal do Pará, Rua Augusto Corrêa, 01 - Guamá, Belém, PA, Brazil, 66075-110
| | - Ronaldo Yuiti Sano
- Departamento de Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, Av. Professor Mello Moraes 1721 Bloco A Sala D9 - Butantã, São Paulo, SP, Brazil, 05508-030.,Departamento de Oftalmologia, Santa Casa de Misericórdia de São Paulo, São Paulo, São Paulo, Brazil
| | - Givago da Silva Souza
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Corrêa, 01 - Guamá, Belém, PA, Brazil, 66075-110.,Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brazil
| | - Jessica Lynch Alfaro
- Institute for Society and Genetics, University of California Los Angeles, Box 957221, 3360 LSB, Los Angeles, CA, USA, 90095-7221.,Department of Anthropology, University of California Los Angeles, Los Angeles, CA, USA
| | - Luis Carlos de Lima Silveira
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Corrêa, 01 - Guamá, Belém, PA, Brazil, 66075-110.,Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brazil
| | - Dora Fix Ventura
- Departamento de Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, Av. Professor Mello Moraes 1721 Bloco A Sala D9 - Butantã, São Paulo, SP, Brazil, 05508-030.,Instituto Israelita de Ensino e Pesquisa Albert Einstein, Hospital Israelita Albert Einstein, São Paulo, São Paulo, Brazil
| | - Daniela Maria Oliveira Bonci
- Departamento de Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, Av. Professor Mello Moraes 1721 Bloco A Sala D9 - Butantã, São Paulo, SP, Brazil, 05508-030. .,Instituto Israelita de Ensino e Pesquisa Albert Einstein, Hospital Israelita Albert Einstein, São Paulo, São Paulo, Brazil.
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9
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Hammond‐Kenny A, Bajo VM, King AJ, Nodal FR. Behavioural benefits of multisensory processing in ferrets. Eur J Neurosci 2017; 45:278-289. [PMID: 27740711 PMCID: PMC5298019 DOI: 10.1111/ejn.13440] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 09/22/2016] [Accepted: 10/10/2016] [Indexed: 12/29/2022]
Abstract
Enhanced detection and discrimination, along with faster reaction times, are the most typical behavioural manifestations of the brain's capacity to integrate multisensory signals arising from the same object. In this study, we examined whether multisensory behavioural gains are observable across different components of the localization response that are potentially under the command of distinct brain regions. We measured the ability of ferrets to localize unisensory (auditory or visual) and spatiotemporally coincident auditory-visual stimuli of different durations that were presented from one of seven locations spanning the frontal hemifield. During the localization task, we recorded the head movements made following stimulus presentation, as a metric for assessing the initial orienting response of the ferrets, as well as the subsequent choice of which target location to approach to receive a reward. Head-orienting responses to auditory-visual stimuli were more accurate and faster than those made to visual but not auditory targets, suggesting that these movements were guided principally by sound alone. In contrast, approach-to-target localization responses were more accurate and faster to spatially congruent auditory-visual stimuli throughout the frontal hemifield than to either visual or auditory stimuli alone. Race model inequality analysis of head-orienting reaction times and approach-to-target response times indicates that different processes, probability summation and neural integration, respectively, are likely to be responsible for the effects of multisensory stimulation on these two measures of localization behaviour.
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Affiliation(s)
- Amy Hammond‐Kenny
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordOX1 3PTUK
| | - Victoria M. Bajo
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordOX1 3PTUK
| | - Andrew J. King
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordOX1 3PTUK
| | - Fernando R. Nodal
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordOX1 3PTUK
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Banihani SM. Loss of binocular vision as direct cause for misrouting of temporal retinal fibers in albinism. Med Hypotheses 2015; 85:458-62. [PMID: 26163060 DOI: 10.1016/j.mehy.2015.06.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 06/23/2015] [Accepted: 06/28/2015] [Indexed: 10/23/2022]
Abstract
In humans, the nasal retina projects to the contralateral hemisphere, whereas the temporal retina projects ipsilaterally. The nasotemporal line that divides the retina into crossed and uncrossed parts coincides with the vertical meridian through the fovea. This normal projection of the retina is severely altered in albinism, in which the nasotemporal line shifted into the temporal retina with temporal retinal fibers cross the midline at the optic chiasm. This study proposes the loss of binocular vision as direct cause for misrouting of temporal retinal fibers and shifting of the nasotemporal line temporally in albinism. It is supported by many observations that clearly indicate that loss of binocular vision causes uncrossed retinal fibers to cross the midline. This hypothesis may alert scientists and clinicians to find ways to prevent or minimize the loss of binocular vision that may occur in some diseases such as albinism and early squint. Hopefully, this will minimize the misrouting of temporal fibers and improve vision in such diseases.
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Affiliation(s)
- Saleh M Banihani
- Anatomy Dept., Medical School, Jordan University of Science and Technology, Irbid 22110, Jordan.
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11
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Hoffmann MB, Dumoulin SO. Congenital visual pathway abnormalities: a window onto cortical stability and plasticity. Trends Neurosci 2014; 38:55-65. [PMID: 25448619 DOI: 10.1016/j.tins.2014.09.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 09/18/2014] [Accepted: 09/26/2014] [Indexed: 12/13/2022]
Abstract
Sensory systems project information in a highly organized manner to the brain, where it is preserved in maps of the sensory structures. These sensory projections are altered in congenital abnormalities, such as anophthalmia, albinism, achiasma, and hemihydranencephaly. Consequently, these abnormalities, profoundly affect the organization of the visual system. Surprisingly, visual perception remains largely intact, except for anophthalmia. Recent brain imaging advances shed light on the mechanisms that underlie this phenomenon. In contrast to animal models, in humans the plasticity of thalamocortical connections appears limited, thus demonstrating the importance of cortical adaptations. We suggest that congenital visual pathway abnormalities provide a valuable model to investigate the principles of plasticity that make visual representations available for perception and behavior in humans.
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Affiliation(s)
- Michael B Hoffmann
- Department of Ophthalmology, Visual Processing Laboratory, Otto-von-Guericke University, Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany.
| | - Serge O Dumoulin
- Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
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12
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Kaule FR, Wolynski B, Gottlob I, Stadler J, Speck O, Kanowski M, Meltendorf S, Behrens-Baumann W, Hoffmann MB. Impact of chiasma opticum malformations on the organization of the human ventral visual cortex. Hum Brain Mapp 2014; 35:5093-105. [PMID: 24771411 DOI: 10.1002/hbm.22534] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 02/21/2014] [Accepted: 04/04/2014] [Indexed: 11/08/2022] Open
Abstract
Congenital malformations of the optic chiasm, such as enhanced and reduced crossing of the optic nerve fibers, are evident in albinism and achiasma, respectively. In early visual cortex the resulting additional visual input from the ipsilateral visual hemifield is superimposed onto the normal retinotopic representation of the contralateral visual field, which is likely due to conservative geniculo-striate projections. Counterintuitively, this organization in early visual cortex does not have profound consequences on visual function. Here we ask, whether higher stages of visual processing provide a correction to the abnormal representation allowing for largely normal perception. To this end we assessed the organization patterns of early and ventral visual cortex in five albinotic, one achiasmic, and five control participants. In albinism and achiasma the mirror-symmetrical superposition of the ipsilateral and contalateral visual fields was evident not only in early visual cortex, but also in the higher areas of the ventral processing stream. Specifically, in the visual areas VO1/2 and PHC1/2 no differences in the extent, the degree of superposition, and the magnitude of the responses were evident in comparison to the early visual areas. Consequently, the highly atypical organization of the primary visual cortex was propagated downstream to highly specialized processing stages in an undiminished and unchanged manner. This indicates largely unaltered cortico-cortical connections in both types of misrouting, i.e., enhanced and reduced crossing of the optic nerves. It is concluded that main aspects of visual function are preserved despite sizable representation abnormalities in the ventral visual processing stream.
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Affiliation(s)
- Falko R Kaule
- Department of Ophthalmology, Visual Processing Laboratory, Otto-von-Guericke University, Magdeburg, Germany; Department of Experimental Psychology, Otto-von-Guericke University, Universitätsplatz 2, Magdeburg, Germany
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Abreu MSL, Machado R, Barbieri F, Freitas NS, Oliveira LR. Anomalous colour in Neotropical mammals: a review with new records for Didelphis sp. (Didelphidae, Didelphimorphia) and Arctocephalus australis (Otariidae, Carnivora). BRAZ J BIOL 2013; 73:185-94. [PMID: 23644801 DOI: 10.1590/s1519-69842013000100020] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 04/02/2012] [Indexed: 11/22/2022] Open
Abstract
Anomalous colourations occur in many tropical vertebrates. However, they are considered rare in wild populations, with very few records for the majority of animal taxa. We report two new cases of anomalous colouration in mammals. Additionally, we compiled all published cases about anomalous pigmentation registered in Neotropical mammals, throughout a comprehensive review of peer reviewed articles between 1950 and 2010. Every record was classified as albinism, leucism, piebaldism or eventually as undetermined pigmentation. As results, we report the new record of a leucistic specimen of opossum (Didelphis sp.) in southern Brazil, as well as a specimen of South American fur seal (Arctocephalus australis) with piebaldism in Uruguay. We also found 31 scientific articles resulting in 23 records of albinism, 12 of leucism, 71 of piebaldism and 92 records classified as undetermined pigmentation. Anomalous colouration is apparently rare in small terrestrial mammals, but it is much more common in cetaceans and michrochiropterans. Out of these 198 records, 149 occurred in cetaceans and 30 in bats. The results related to cetaceans suggest that males and females with anomolous pigmentation are reproductively successful and as a consequence their frequencies are becoming higher in natural populations. In bats, this result can be related to the fact these animals orient themselves primarily through echolocation, and their refuges provide protection against light and predation. It is possible that anomalous colouration occurs more frequently in other Neotropical mammal orders, which were not formally reported. Therefore, we encourage researchers to publish these events in order to better understand this phenomenon that has a significant influence on animal survival.
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Affiliation(s)
- M S L Abreu
- Laboratório de Ecologia de Mamíferos, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brazil
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Williams JG, Graham JE, Laste NJ, Malakoff RL. Tetralogy of Fallot in a Young Ferret (Mustela putorius furo). J Exot Pet Med 2011. [DOI: 10.1053/j.jepm.2011.04.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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Dominant vertical orientation processing without clustered maps: early visual brain dynamics imaged with voltage-sensitive dye in the pigeon visual Wulst. J Neurosci 2010; 30:6713-25. [PMID: 20463233 DOI: 10.1523/jneurosci.4078-09.2010] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The pigeon is a widely established behavioral model of visual cognition, but the processes along its most basic visual pathways remain mostly unexplored. Here, we report the neuronal population dynamics of the visual Wulst, an assumed homolog of the mammalian striate cortex, captured for the first time with voltage-sensitive dye imaging. Responses to drifting gratings were characterized by focal emergence of activity that spread extensively across the entire Wulst, followed by rapid adaptation that was most effective in the surround. Using additional electrophysiological recordings, we found cells that prefer a variety of orientations. However, analysis of the imaged spatiotemporal activation patterns revealed no clustered orientation map-like arrangements as typically found in the primary visual cortices of many mammalian species. Instead, the vertical orientation was overrepresented, both in terms of the imaged population signal, as well as the number of neurons preferring the vertical orientation. Such enhanced selectivity for the vertical orientation may result from horizontal motion vectors that trigger adaptation to the extensive flow field input during natural behavior. Our findings suggest that, although the avian visual Wulst is homologous to the primary visual cortex in terms of its gross anatomical connectivity and topology, its detailed operation and internal organization is still shaped according to specific input characteristics.
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Banihani SM. Crossing of neuronal pathways: is it a response to the occurrence of separated parts for the body (limbs, eyes, etc.) during evolution? Med Hypotheses 2009; 74:741-5. [PMID: 19926228 DOI: 10.1016/j.mehy.2009.10.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Accepted: 10/18/2009] [Indexed: 10/20/2022]
Abstract
Most sensory and motor pathways in the central nervous system cross the midline. Comparing between different neuronal pathways in different species suggest that, fibers crossing is most probably a response to the development of separated parts for the body during the process of evolution. This hypothesis proposes direct link between the occurrence of fibers crossing and the occurrence of separated parts of the body such as lateral eyes and limbs. It is supported by many observations that clearly indicate that different neuronal pathways in different species cross the midline when they carry separated information and run ipsilaterally when they carry shared information. Carrying separated information seems to create a need for functional coordination between the two halves of the nervous system which seems to be mediated by the fibers crossing. This hypothesis may alert scientists to study certain aspects of sensory and/or motor pathways in different species. It also enable the students to remember whether a pathway is uncrossed or crossed based on whether this pathway carry shared or separated information.
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Affiliation(s)
- Saleh M Banihani
- Anatomy Department, Medical School, Jordan University of Science and Technology, Irbid 22110, Jordan.
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Retinal projections to the accessory optic system in pigmented and albino ferrets (Mustela putorius furo). Exp Brain Res 2009; 199:333-43. [PMID: 19139858 DOI: 10.1007/s00221-008-1690-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Accepted: 12/10/2008] [Indexed: 10/21/2022]
Abstract
We investigated if a reduced specificity of the retinal projection to the accessory optic system might be responsible for the loss of direction selectivity in the nucleus of the optic tract and dorsal terminal nucleus (NOT-DTN) and, in consequence of this, the optokinetic deficits in albino ferrets. Under electrophysiological control we performed dual tracer injections into the NOT-DTN and the medial terminal nucleus (MTN). Retrogradely labelled ganglion cells were found in the visual streak, the dorsal, and the ventral retina both after injections into the NOTDTN and the MTN indicating that both nuclei receive input from the same retinal regions. The distribution and spacing of labelled ganglion cells did not differ between pigmented and albino ferrets. However, retinal ganglion cells projecting simultaneously to both the NOT-DTN and the MTN occurred only in albino ferrets. These results suggest that a reduced specificity of the projection pattern of direction specific ganglion cells may contribute to the loss of direction selectivity in the NOT-DTN in albino ferrets.
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Kalberlah C, Distler C, Hoffmann KP. Sensitivity to relative disparity in early visual cortex of pigmented and albino ferrets. Exp Brain Res 2008; 192:379-89. [PMID: 18726091 DOI: 10.1007/s00221-008-1545-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Accepted: 08/06/2008] [Indexed: 11/28/2022]
Abstract
To investigate binocular interactions as the neuronal substrate for disparity sensitivity in the ferret (Mustela putorius furo), we measured the effects of relative horizontal disparities on responses of neurons in areas 17 and 18 of the visual cortex. Stimulation by moving bars and sinusoidal gratings showed that about half of our sample in pigmented ferrets was sensitive to relative horizontal disparity. This also included many neurons, which were classified as only monocularly activated when testing either eye alone. However, the tuning width was about two or three times coarser (median tuning width 4 degrees of visual angle) than that in the cat. In albino ferrets, only 8% of the neurons in the early visual cortex displayed some sort of disparity-dependent binocular interactions, but none could be clearly identified as relative disparity-coding neuron.
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Affiliation(s)
- C Kalberlah
- Allgemeine Zoologie und Neurobiologie, Ruhr-Universität Bochum, Postfach 102148, 44780, Bochum, Germany
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Heiduschka P, Schraermeyer U. Comparison of visual function in pigmented and albino rats by electroretinography and visual evoked potentials. Graefes Arch Clin Exp Ophthalmol 2008; 246:1559-73. [DOI: 10.1007/s00417-008-0895-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 06/10/2008] [Accepted: 06/16/2008] [Indexed: 11/25/2022] Open
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Hoffmann MB, Seufert PS, Schmidtborn LC. Perceptual relevance of abnormal visual field representations: static visual field perimetry in human albinism. Br J Ophthalmol 2007; 91:509-13. [PMID: 17372340 PMCID: PMC1994751 DOI: 10.1136/bjo.2006.094854] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND In human albinism the plasticity of the visual system is challenged, as part of the temporal retina projects abnormally to the contralateral hemisphere. AIM To investigate whether the sensitivity of the abnormally projecting temporal retina is preserved. METHODS Light spot detection sensitivities were assessed in the central 20 degrees of the visual field in 15 patients with albinism and electrophysiologically determined extent of the retinal projection abnormality, and in 6 controls. The sensitivities were determined monocularly with static white-on-white perimetry using Octopus 101. RESULTS In the patients with albinism, the sensitivity of the abnormally projecting part of the temporal retina was not selectively reduced. Apart from the vicinity of the papilla, there was no significant sensitivity difference between nasal and temporal retina in both patients with albinism and controls. CONCLUSIONS While in the present study the papilla-induced scotoma was detected in those with albinism tested, there was no indication of a selective visual field defect induced by the projection abnormality. This contrasts with the selective visual field defects observed in some animal models of albinism, and indicates that, in humans, mechanisms of cortical self-organisation make the abnormal representation available for visual perception.
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Affiliation(s)
- Michael B Hoffmann
- Universitäts-Augenklinik, Visual Processing Lab, Leipziger Street 44, 39120 Magdeburg, UK.
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Hupfeld D, Distler C, Hoffmann KP. Motion perception deficits in albino ferrets (Mustela putorius furo). Vision Res 2006; 46:2941-8. [PMID: 16647737 DOI: 10.1016/j.visres.2006.02.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2005] [Revised: 02/20/2006] [Accepted: 02/23/2006] [Indexed: 11/23/2022]
Abstract
Albino ferrets contrary to their pigmented conspecifics show no optokinetic nystagmus. Therefore, in this study motion perception was compared between pigmented and albino ferrets (Mustela putorius furo) trained to discriminate between coherently moving random dot patterns and dynamic noise stimuli in a two-alternative forced choice task. Fully coherently versus incoherently moving patterns could be distinguished by ferrets of both phenotypes. Motion coherence thresholds, however, were significantly higher in albinos. These results indicate that albino ferrets are not motion blind as could be expected from their total lack of optokinetic reactions. However, they are severely impaired in global motion perception.
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Affiliation(s)
- D Hupfeld
- Allgemeine Zoologie & Neurobiologie, Ruhr-Universitaet Bochum, Universitaetsstr. 150, ND 7/31, 44780 Bochum, Germany
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Neuroanatomical, molecular genetic, and behavioral correlates of fragile X syndrome. ACTA ACUST UNITED AC 2006; 53:27-38. [PMID: 16844227 DOI: 10.1016/j.brainresrev.2006.06.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2005] [Revised: 06/08/2006] [Accepted: 06/13/2006] [Indexed: 12/26/2022]
Abstract
Fragile X syndrome (FXS) is a leading cause of inherited mental retardation. In the vast majority of cases, this X-linked disorder is due to a CGG expansion in the 5' untranslated region of the fmr-1 gene and the resulting decreased expression of its associated protein, FMRP. FXS is characterized by a number of cognitive, behavioral, anatomical, and biological abnormalities. FXS provides a unique opportunity to study the consequence of mutation in a single gene on the development and proper functioning of the CNS. The current focus on the role of FMRP in neuronal maturation makes it timely to assemble the extant information on how reduced expression of the fmr-1 gene leads to neuronal dysmorphology. The purpose of this review is to summarize recent genetic, neuroanatomical, and behavioral studies of fragile X syndrome and to offer potential mechanisms to account for the pleiotropic phenotype of this disorder.
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Abstract
In albinism there is an abnormal projection of part of the temporal retina to the visual cortex contralateral to the eye. This projection, together with the normally routed fibers from nasal retina, provides a cortical hemisphere with visual input from more than the normal hemifield of visual space. In many mammalian models of albinism, a possible sensory mismatch in the visual cortex is avoided either by reorganization of the thalamocortical connections to give the abnormal input an exclusive cortical representation, or by the abnormal input being substantially suppressed. In this study we examine, with fMRI, how the human visual cortex topographically maps its input in albinism. We find that the input from temporal retina is not substantially suppressed and forms a retinotopic mapping that is superimposed on the mapping of the nasal retina in striate and extrastriate areas. The abnormal routing of temporal fibers is not total, with the line of decussation shifting to between 6 and 14 degrees into temporal retina. Our results indicate that the abnormal input to visual cortex in human albinism does not undergo topographic reorganization between the thalamus and cortex. Furthermore, the abnormal input is not significantly suppressed in either striate or extrastriate areas. The topographic mapping that we report in human does not conform, therefore, to the commonly observed patterns in other mammals but takes the form of the "true albino" pattern that has been reported rarely in cat and in the only other individual primate studied.
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