DOCSLIB.ORG

Brain Sciences

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Brain Sciences brain sciences Review Parallel Emergence of a Compartmentalized Striatum with the Phylogenetic Development of the Cerebral Cortex Tadashi Hamasaki 1 and Satoshi Goto 2,3,* 1 Department of Neurosurgery, Kumamoto University Medical School, Kumamoto 860-8556, Japan; [email protected] 2 Department of Neurodegenerative Disorders Research, Institute of Biomedical Sciences, Graduate School of Medical Sciences, Tokushima University, Tokushima 770-8503, Japan 3 Parkinson’s Disease and Dystonia Research Center, Tokushima University Hospital, Tokushima University, Tokushima 770-8503, Japan * Correspondence: [email protected]; Tel.: +81-88-633-7206; Fax: +81-88-633-7208 Received: 7 March 2019; Accepted: 17 April 2019; Published: 19 April 2019 Abstract: The intricate neuronal architecture of the striatum plays a pivotal role in the functioning of the basal ganglia circuits involved in the control of various aspects of motor, cognitive, and emotional functions. Unlike the cerebral cortex, which has a laminar structure, the striatum is primarily composed of two functional subdivisions (i.e., the striosome and matrix compartments) arranged in a mosaic fashion. This review addresses whether striatal compartmentalization is present in non-mammalian vertebrates, in which simple cognitive and behavioral functions are executed by primitive sensori-motor systems. Studies show that neuronal subpopulations that share neurochemical and connective properties with striosomal and matrix neurons are present in the striata of not only anamniotes (fishes and amphibians), but also amniotes (reptiles and birds). However, these neurons do not form clearly segregated compartments in these vertebrates, suggesting that such compartmentalization is unique to mammals. In the ontogeny of the mammalian forebrain, the later-born matrix neurons disperse the early-born striosome neurons into clusters to form the compartments in tandem with the development of striatal afferents from the cortex. We propose that striatal compartmentalization in mammals emerged in parallel with the evolution of the cortex and possibly enhanced complex processing of sensory information and behavioral flexibility phylogenetically. Keywords: compartmentalization; matrix; striosome; phylogenetic development: striatum; vertebrate 1. Introduction The striatum is a key component of the basal ganglia circuit, which is involved in normal motor, cognitive, and emotional functions. Dysregulation of striatal function contributes to a variety of neurological and neurobehavioral disorders [1]. Accurate processing in the basal ganglia circuit is thus required for normal movements and behaviors in humans and depends on a balance between input and output neurotransmission, which in turn is reinforced by an organized cellular architecture [1]. The striatum is the primary receptive nucleus of the basal ganglia circuit and receives inputs from all cortical areas. However, the structural organization of the mammalian striatum is unique and is characterized by a mosaic pattern, distinct from the laminar cerebral cortex [2,3]. Two neurochemically-specified subdivisions, i.e., striosomes (patches) and the extrastriosomal matrix, exist in the mammalian striatum. This novel arrangement is related to neurotransmitter interactions and striatal input and output systems. The striosome is organized in a labyrinthine structure in 3D Brain Sci. 2019, 9, 90; doi:10.3390/brainsci9040090 www.mdpi.com/journal/brainsci Brain Sci. 2019, 9, x FOR PEER REVIEW 2 of 14 Brain Sci. 2019, 9, 90 2 of 14 exist in the mammalian striatum. This novel arrangement is related to neurotransmitter interactions and striatal input and output systems. The striosome is organized in a labyrinthine structure in 3D space,space, andand the the matrix matrix occupies occupies the spacethe space surrounding surroun theding striosome. the striosome. The matrix-based The matrix-based output pathway output actspathway as a push-pullacts as a push-pull system to increasesystem to or increase decrease or movement decrease movement through direct through or indirect direct or pathways, indirect respectivelypathways, respectively [1]. The striosomal [1]. The striosomal pathway pathway likely exerts likely critical exerts motor critical control motor control by modulating by modulating nigral dopaminergicnigral dopaminergic outputs [outputs2,4]. Growing [2,4]. evidenceGrowing suggestsevidence that suggests the dysregulation that the dysregulation of striatal compartments of striatal mightcompartments cause movement might cause disorders movement [1,5–7 disorders]. [1,5–7]. LittleLittle isis known known about about striatal striatal compartmentalization compartmentalization in non-mammalian in non-mammalian vertebrates vertebrates with primitive with motorprimitive functions motor andfunctions behaviors. and Inbehaviors. this review, In wethis focusreview, on whetherwe focus the on mosaic whether organization the mosaic of theorganization striatum isof uniquethe striatum to animals is unique with to animals well-developed with well-developed cerebral cortices. cerebral We cortices. postulate We thatpostulate clear compartmentalizationthat clear compartmentalization in the striatum in the striatum emerges em parallelerges parallel to the to phylogenetic the phylogenetic development development of the of cerebralthe cerebral cortex. cortex. Do neurochemically-identified Do neurochemically-identifi striosomeed striosome and matrix and neurons matrix exist neurons in non-mammalian exist in non- vertebratesmammalian or vertebrates anamniotes? or Neurochemicalanamniotes? Neurochemica markers to distinguishl markers striosometo distinguish and matrixstriosome compartments and matrix werecompartments extensively were reviewed extensively by Crittenden reviewed and by Graybiel Crittenden [1]. Forand example, Graybiel D1-type [1]. For dopamine example, receptorD1-type (D1R),dopamine glutamate receptor receptor, (D1R), ionotropic,glutamate receptor, AMPA 1 (GluR1),ionotropic, substance AMPA P1 (SP),(GluR1), and substance tyrosine hydroxylase P (SP), and (TH)tyrosine in dopaminergichydroxylase (TH) afferent in terminalsdopaminergic were affe markersrent terminals for the striosome. were markers Acetylcholine for the striosome. esterase (AChE),Acetylcholine calbindin esterase (CB), (AChE), choline calbindin acetyltransferase (CB), cho (ChAT),line acetyltransferase enkephalin (ENK), (ChAT), and enkephalin neuropeptide (ENK), Y (NPY)and neuropeptide were markers Y (NPY) for the were matrix. markers Here, for we the review matrix. the Here, literature we review on expression the literature patterns on expression of striatal compartmentpatterns of striatal markers compartment throughout markers the vertebrate throughout phylogeny the vertebrate (for reference phylogeny see, Figure (for1). reference Evolutional see, changesFigure 1). in fundamentalEvolutional architectureschanges in fundamental in the striatum architectures were extensively in the addressed striatum bywere Reiner extensively et al. [8] andaddressed Smeets by et Reiner al. [9] and et al. are [8] not and presented Smeets et in al. this [9] review. and are not presented in this review. FigureFigure 1.1. AA phylogeneticphylogenetic treetree ofof vertebratevertebrate evolution.evolution. AA diagramdiagram showingshowing thethe lineslines ofof evolutionaryevolutionary descentdescent ofof didifferentfferent vertebratesvertebrates fromfrom aa commoncommon ancestor.ancestor. TheThe ancestralancestral bonybony fishfish gavegave riserise toto ancestralancestral amphibians.amphibians. Through Through water-land water-land transition, ancest ancestralral amphibians gave rise to stem anamniotes,anamniotes, whichwhich thenthen separatelyseparately evolvedevolved intointo sauropsidssauropsids andand therapsids.therapsids. SauropsidsSauropsids areare notnot onlyonly thethe ancestorsancestors ofof existing reptiles but but also also gave gave rise rise to to the the ancestors ancestors of birds. of birds. Mammalian Mammalian species species have have evolved evolved from fromtherapsid therapsid ancestors, ancestors, although although many many groups groups of the of therapsids the therapsids have have become become extinct extinct (dashed (dashed line). line). The Thesix-layered six-layered cortex cortex waswas inherited inherited by the by mammalian the mammalian ancestor ancestor of therapsids of therapsids (green (green line) line) more more than than 200 200million million years years ago ago[10]. [10 Modified]. Modified from from Jarvis Jarvis et al. et [11]. al. [11 ]. 2. The Striatum in Anamniotes 2. The Striatum in Anamniotes Although the structure of the basal ganglia in early vertebrates has been extensively studied [12–15], Although the structure of the basal ganglia in early vertebrates has been extensively studied [12– little is known about striatal compartmentalization. Major neurotransmitters such as acetylcholine 15], little is known about striatal compartmentalization. Major neurotransmitters such as and dopamine, neuropeptides such as SP and ENK, and related enzyme systems such as AChE or acetylcholine and dopamine, neuropeptides such as SP and ENK, and related enzyme systems such TH, developed very early in animal evolution [8]. Their expression patterns can thus be used to study as AChE or TH, developed very early in animal evolution [8]. Their expression patterns can thus be structural differences of the basal ganglia in diverse living anamniote species. used to study structural differences of the
Load more

Recommended publications
  • Fish Do Not Feel Pain and Its Implications for Understanding Phenomenal Consciousness
    Biol Philos (2015) 30:149–165 DOI 10.1007/s10539-014-9469-4 Fish do not feel pain and its implications for understanding phenomenal consciousness Brian Key Received: 14 April 2014 / Accepted: 6 December 2014 / Published online: 16 December 2014 Ó The Author(s) 2014. This article is published with open access at Springerlink.com Abstract Phenomenal consciousness or the subjective experience of feeling sen- sory stimuli is fundamental to human existence. Because of the ubiquity of their subjective experiences, humans seem to readily accept the anthropomorphic extension of these mental states to other animals. Humans will typically extrapolate feelings of pain to animals if they respond physiologically and behaviourally to noxious stimuli. The alternative view that fish instead respond to noxious stimuli reflexly and with a limited behavioural repertoire is defended within the context of our current understanding of the neuroanatomy and neurophysiology of mental states. Consequently, a set of fundamental properties of neural tissue necessary for feeling pain or experiencing affective states in vertebrates is proposed. While mammals and birds possess the prerequisite neural architecture for phenomenal consciousness, it is concluded that fish lack these essential characteristics and hence do not feel pain. Keywords Fish Á Pain Á Phenomenal consciousness Á Affective states Á Avoidance learning Á Neocortex Á Pallium Introduction There is a belief in some scientific and lay communities that because fish respond behaviourally to noxious stimuli, then ipso facto, fish feel pain. Sneddon (2011) clearly articulates the logic by stating: ‘‘to explore the possibility of pain perception in nonhumans we use indirect measures similar to those used for human infants who cannot convey whether they are in pain.
    [Show full text]
  • The Prefrontal Cortex of the Primate: a Synopsis
    Psychobiology 2000,28 (2),125-13/ The prefrontal cortex of the primate: A synopsis JOAQuiN M. FUSTER University of California, Los Angeles, California The prefrontal cortex is one of the latest regions of the neocortex to develop, in both phylogeny and ontogeny. In the primate, the prefrontal cortex is anatomically divided into three major sectors: medial, orbital (or inferior), and dorsolateral. The dorsolateral sector is the association cortex of the convex­ ity of the frontal lobe. Phylogenetically and ontogenetically, this part of the prefrontal cortex is the one to develop last and most. It is the neural substrate of the higher cognitive functions that reach their maximum development in the human brain. The-most general and distinctive function of the dorso­ lateral prefrontal cortex is the temporal organization of goal-directed actions. In the human, this role extends to the domains of speech and reasoning. Two temporally symmetrical and mutually comple­ mentary cognitive functions-one retrospective and the other prospective-support that general pre­ frontal function of temporal organization: (1) active short-term memory, also called working memory; (2) prospective or preparatory set. The dorsolateral prefrontal cortex interacts with other cortical and subcortical structures in those two time-bridging functions at the basis of the temporal organization of behavior. This article presents in summary form the most salient the cortex of the dorsal and lateral convexity ofthe ante­ empirical facts known to date on the structure and func­ rior part of the frontal lobe (Brodmann's cytoarchitectonic tions of the prefrontal cortex of the human and nonhuman area 46, and lateral parts of areas 8, 9, 10, and 11); (2) me­ primate.
    [Show full text]
  • Corticostriatal Interactions During Learning, Memory Processing, and Decision Making
    The Journal of Neuroscience, October 14, 2009 • 29(41):12831–12838 • 12831 Mini-Symposium Corticostriatal Interactions during Learning, Memory Processing, and Decision Making Cyriel M. A. Pennartz,1 Joshua D. Berke,2,3 Ann M. Graybiel,4,5 Rutsuko Ito,6 Carien S. Lansink,1 Matthijs van der Meer,7 A. David Redish,7 Kyle S. Smith,4,5 and Pieter Voorn8 1University of Amsterdam, Swammerdam Institute for Life Sciences Center for Neuroscience, 1098 XH Amsterdam, The Netherlands, 2Department of Psychology and 3Neuroscience Program, University of Michigan, Ann Arbor, Michigan 48109, 4Department of Brain and Cognitive Sciences and 5McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, 6Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, United Kingdom, 7Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, and 8Department of Anatomy, Research Institute Neurosciences, Vrije Universiteit University Medical Center, 1007 MB Amsterdam, The Netherlands This mini-symposium aims to integrate recent insights from anatomy, behavior, and neurophysiology, highlighting the anatom- ical organization, behavioral significance, and information-processing mechanisms of corticostriatal interactions. In this sum- mary of topics, which is not meant to provide a comprehensive survey, we will first review the anatomy of corticostriatal circuits, comparing different ways by which “loops” of cortical–basal ganglia circuits communicate. Next, we will address the causal importance and systems-neurophysiological mechanisms of corticostriatal interactions for memory, emphasizing the communi- cation between hippocampus and ventral striatum during contextual conditioning. Furthermore, ensemble recording techniques have been applied to compare information processing in the dorsal and ventral striatum to predictions from reinforcement learning theory.
    [Show full text]
  • Emotional and Spatial Learning in Goldfish Is Dependent on Different
    European Journal of Neuroscience, Vol. 21, pp. 2800–2806, 2005 ª Federation of European Neuroscience Societies Emotional and spatial learning in goldfish is dependent on different telencephalic pallial systems Manuel Portavella1,* and Juan P. Vargas2 1Departamento de Psicologı´a Experimental. Universidad de Sevilla. C ⁄ Camilo Jose´ Cela s ⁄ n, E-41018, Seville, Spain 2SISSA. Cognitive Neuroscience Sector. Via Beirut, 2 ⁄ 4, 34014 Trieste, Italy Keywords: amygdala, avoidance learning, brain evolution, hippocampus, memory systems Abstract In mammals, the amygdala and the hippocampus are involved in different aspects of learning. Whereas the amygdala complex is involved in emotional learning, the hippocampus plays a critical role in spatial and contextual learning. In fish, it has been suggested that the medial and lateral region of the telencephalic pallia might be the homologous neural structure to the mammalian amygdala and hippocampus, respectively. Although there is evidence of the implication of medial and lateral pallium in several learning processes, it remains unclear whether both pallial areas are involved distinctively in different learning processes. To address this issue, we examined the effect of selective ablation of the medial and lateral pallium on both two-way avoidance and reversal spatial learning in goldfish. The results showed that medial pallium lesions selectively impaired the two-way avoidance task. In contrast, lateral pallium ablations impaired the spatial task without affecting the avoidance performance. These results indicate that the medial and lateral pallia in fish are functionally different and necessary for emotional and spatial learning, respectively. Present data could support the hypothesis that a sketch of these regions of the limbic system, and their associated functions, were present in the common ancestor of fish and terrestrial vertebrates 400 million years ago.
    [Show full text]
  • Cortical Layers: What Are They Good For? Neocortex
    Cortical Layers: What are they good for? Neocortex L1 L2 L3 network input L4 computations L5 L6 Brodmann Map of Cortical Areas lateral medial 44 areas, numbered in order of samples taken from monkey brain Brodmann, 1908. Primary visual cortex lamination across species Balaram & Kaas 2014 Front Neuroanat Cortical lamination: not always a six-layered structure (archicortex) e.g. Piriform, entorhinal Larriva-Sahd 2010 Front Neuroanat Other layered structures in the brain Cerebellum Retina Complexity of connectivity in a cortical column • Paired-recordings and anatomical reconstructions generate statistics of cortical connectivity Lefort et al. 2009 Information flow in neocortical microcircuits Simplified version “computational Layer 2/3 layer” Layer 4 main output Layer 5 main input Layer 6 Thalamus e - excitatory, i - inhibitory Grillner et al TINS 2005 The canonical cortical circuit MAYBE …. DaCosta & Martin, 2010 Excitatory cell types across layers (rat S1 cortex) Canonical models do not capture the diversity of excitatory cell classes Oberlaender et al., Cereb Cortex. Oct 2012; 22(10): 2375–2391. Coding strategies of different cortical layers Sakata & Harris, Neuron 2010 Canonical models do not capture the diversity of firing rates and selectivities Why is the cortex layered? Do different layers have distinct functions? Is this the right question? Alternative view: • When thinking about layers, we should really be thinking about cell classes • A cells class may be defined by its input connectome and output projectome (and some other properties) • The job of different classes is to (i) make associations between different types of information available in each cortical column and/or (ii) route/gate different streams of information • Layers are convenient way of organising inputs and outputs of distinct cell classes Excitatory cell types across layers (rat S1 cortex) INTRATELENCEPHALIC (IT) | PYRAMIDAL TRACT (PT) | CORTICOTHALAMIC (CT) From Cereb Cortex.
    [Show full text]
  • The Structural Model: a Theory Linking Connections, Plasticity, Pathology, Development and Evolution of the Cerebral Cortex
    Brain Structure and Function https://doi.org/10.1007/s00429-019-01841-9 REVIEW The Structural Model: a theory linking connections, plasticity, pathology, development and evolution of the cerebral cortex Miguel Ángel García‑Cabezas1 · Basilis Zikopoulos2,3 · Helen Barbas1,3 Received: 11 October 2018 / Accepted: 29 January 2019 © Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract The classical theory of cortical systematic variation has been independently described in reptiles, monotremes, marsupials and placental mammals, including primates, suggesting a common bauplan in the evolution of the cortex. The Structural Model is based on the systematic variation of the cortex and is a platform for advancing testable hypotheses about cortical organization and function across species, including humans. The Structural Model captures the overall laminar structure of areas by dividing the cortical architectonic continuum into discrete categories (cortical types), which can be used to test hypotheses about cortical organization. By type, the phylogenetically ancient limbic cortices—which form a ring at the base of the cerebral hemisphere—are agranular if they lack layer IV, or dysgranular if they have an incipient granular layer IV. Beyond the dysgranular areas, eulaminate type cortices have six layers. The number and laminar elaboration of eulaminate areas differ depending on species or cortical system within a species. The construct of cortical type retains the topology of the systematic variation of the cortex and forms the basis for a predictive Structural Model, which has successfully linked cortical variation to the laminar pattern and strength of cortical connections, the continuum of plasticity and stability of areas, the regularities in the distribution of classical and novel markers, and the preferential vulnerability of limbic areas to neurodegenerative and psychiatric diseases.
    [Show full text]
  • Perspectives
    PERSPECTIVES reptiles, to birds and mammals, to primates OPINION and, finally, to humans — ascending from ‘lower’ to ‘higher’ intelligence in a chrono- logical series. They believed that the brains Avian brains and a new understanding of extant vertebrates retained ancestral structures, and, therefore, that the origin of of vertebrate brain evolution specific human brain subdivisions could be traced back in time by examining the brains of extant non-human vertebrates. In The Avian Brain Nomenclature Consortium* making such comparisons, they noted that the main divisions of the human CNS — Abstract | We believe that names have a pallium is nuclear, and the mammalian the spinal cord, hindbrain, midbrain, thala- powerful influence on the experiments we cortex is laminar in organization, the avian mus, cerebellum and cerebrum or telen- do and the way in which we think. For this pallium supports cognitive abilities similar cephalon — were present in all vertebrates reason, and in the light of new evidence to, and for some species more advanced than, (FIG. 1a). Edinger, however, noted that the about the function and evolution of the those of many mammals. To eliminate these internal organization of the telencephala vertebrate brain, an international consortium misconceptions, an international forum of showed the most pronounced differences of neuroscientists has reconsidered the neuroscientists (BOX 1) has, for the first time between species. In mammals, the outer traditional, 100-year-old terminology that is in 100 years, developed new terminology that part of the telencephalon was found to have used to describe the avian cerebrum. Our more accurately reflects our current under- prominently layered grey matter (FIG.
    [Show full text]
  • Foxg1confines Cajal–Retzius Neuronogenesis and Hippocampal
    The Journal of Neuroscience, April 27, 2005 • 25(17):4435–4441 • 4435 Development/Plasticity/Repair Foxg1 Confines Cajal–Retzius Neuronogenesis and Hippocampal Morphogenesis to the Dorsomedial Pallium Luca Muzio and Antonello Mallamaci Department of Biological and Technological Research, San Raffaele Scientific Institute, 20132 Milan, Italy It has been suggested that cerebral cortex arealization relies on positional values imparted to early cortical neuroblasts by transcription factor genes expressed within the pallial field in graded ways. Foxg1, encoding for one of these factors, previously was reported to be necessary for basal ganglia morphogenesis, proper tuning of cortical neuronal differentiation rates, and the switching of cortical neuro- blasts from early generation of primordial plexiform layer to late production of cortical plate. Being expressed along a rostral/lateral high- to-caudal/medial low gradient, Foxg1, moreover, could contribute to shaping the cortical areal profile as a repressor of caudomedial fates. Wetestedthispredictionbyavarietyofapproachesandfoundthatitwascorrect.WefoundthatoverproductionofCajal–Retziusneurons characterizing Foxg1Ϫ/Ϫ mutants does not arise specifically from blockage of laminar histogenetic progression of neocortical neuro- blasts, as reported previously, but rather reflects lateral-to-medial repatterning of their cortical primordium. Even if lacking a neocortical plate, Foxg1Ϫ/Ϫ embryos give rise to structures, which, for molecular properties and birthdating profile, are highly reminiscent of hippocampal plate and dentate blade. Remarkably, in the absence of Foxg1, additional inactivation of the medial fates promoter Emx2, although not suppressing cortical specification, conversely rescues overproduction of Reelin on neurons. Key words: Foxg1; Emx2; Wnt types; hippocampus; neocortex; Cajal–Retzius cells Introduction neuronogenesis (Xuan et al., 1995; Dou et al., 1999; Seoane et al., Areal specification of cortical neurons is an extremely complex 2004).
    [Show full text]
  • Neocortex: Consciousness Cerebellum
    Grey matter (chips) White matter (the wiring: the brain mainly talks to itself) Neocortex: consciousness Cerebellum: unconscious control of posture & movement brains 1. Golgi-stained section of cerebral cortex 2. One of Ramon y Cajal’s faithful drawings showing nerve cell diversity in the brain cajal Neuropil: perhaps 1 km2 of plasma membrane - a molecular reaction substrate for 1024 voltage- and ligand-gated ion channels. light to Glia: 3 further cell types 1. Astrocytes: trophic interface with blood, maintain blood brain barrier, buffer excitotoxic neurotransmitters, support synapses astros Oligodendrocytes: myelin insulation oligos Production persists into adulthood: radiation myelopathy 3. Microglia: resident macrophages of the CNS. Similarities and differences with Langerhans cells, the professional antigen-presenting cells of the skin. 3% of all cells, normally renewed very slowly by division and immigration. Normal Neurosyphilis microglia Most adult neurons are already produced by birth Peak synaptic density by 3 months EMBRYONIC POSTNATAL week: 0 6 12 18 24 30 36 Month: 0 6 12 18 24 30 36 Year: 4 8 12 16 20 24 Cell birth Migration 2* Neurite outgrowth Synaptogenesis Myelination 1* Synapse elimination Modified from various sources inc: Andersen SL Neurosci & Biobehav Rev 2003 Rakic P Nat Rev Neurosci 2002 Bourgeois Acta Pediatr Suppl 422 1997 timeline 1 Synaptogenesis 100% * Rat RTH D BI E A Density of synapses in T PUBERTY primary visual cortex H at different times post- 0% conception. 100% (logarithmic scale) RTH Cat BI D E A T PUBERTY H The density values equivalent 0% to 100% vary between species 100% but in Man the peak value is Macaque 6 3 RTH 350 x10 synapses per mm BI D E PUBERTY A T The peak rate of synapse H formation is at birth in the 0% macaque: extrapolating to 100% the entire cortex, this Man RTH BI amounts to around 800,000 D E synapses formed per sec.
    [Show full text]
  • The Neocortex of Cetartiodactyls. II. Neuronal Morphology of the Visual and Motor Cortices in the Giraffe (Giraffa Camelopardalis)
    Brain Struct Funct (2015) 220:2851–2872 DOI 10.1007/s00429-014-0830-9 ORIGINAL ARTICLE The neocortex of cetartiodactyls. II. Neuronal morphology of the visual and motor cortices in the giraffe (Giraffa camelopardalis) Bob Jacobs • Tessa Harland • Deborah Kennedy • Matthew Schall • Bridget Wicinski • Camilla Butti • Patrick R. Hof • Chet C. Sherwood • Paul R. Manger Received: 11 May 2014 / Accepted: 21 June 2014 / Published online: 22 July 2014 Ó Springer-Verlag Berlin Heidelberg 2014 Abstract The present quantitative study extends our of aspiny neurons in giraffes appeared to be similar to investigation of cetartiodactyls by exploring the neuronal that of other eutherian mammals. For cross-species morphology in the giraffe (Giraffa camelopardalis) neo- comparison of neuron morphology, giraffe pyramidal cortex. Here, we investigate giraffe primary visual and neurons were compared to those quantified with the same motor cortices from perfusion-fixed brains of three su- methodology in African elephants and some cetaceans badults stained with a modified rapid Golgi technique. (e.g., bottlenose dolphin, minke whale, humpback whale). Neurons (n = 244) were quantified on a computer-assis- Across species, the giraffe (and cetaceans) exhibited less ted microscopy system. Qualitatively, the giraffe neo- widely bifurcating apical dendrites compared to ele- cortex contained an array of complex spiny neurons that phants. Quantitative dendritic measures revealed that the included both ‘‘typical’’ pyramidal neuron morphology elephant and humpback whale had more extensive den- and ‘‘atypical’’ spiny neurons in terms of morphology drites than giraffes, whereas the minke whale and bot- and/or orientation. In general, the neocortex exhibited a tlenose dolphin had less extensive dendritic arbors.
    [Show full text]
  • NEUROGENESIS in the ADULT BRAIN: New Strategies for Central Nervous System Diseases
    7 Jan 2004 14:25 AR AR204-PA44-17.tex AR204-PA44-17.sgm LaTeX2e(2002/01/18) P1: GCE 10.1146/annurev.pharmtox.44.101802.121631 Annu. Rev. Pharmacol. Toxicol. 2004. 44:399–421 doi: 10.1146/annurev.pharmtox.44.101802.121631 Copyright c 2004 by Annual Reviews. All rights reserved First published online as a Review in Advance on August 28, 2003 NEUROGENESIS IN THE ADULT BRAIN: New Strategies for Central Nervous System Diseases ,1 ,2 D. Chichung Lie, Hongjun Song, Sophia A. Colamarino,1 Guo-li Ming,2 and Fred H. Gage1 1Laboratory of Genetics, The Salk Institute, La Jolla, California 92037; email: [email protected], [email protected], [email protected] 2Institute for Cell Engineering, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287; email: [email protected], [email protected] Key Words adult neural stem cells, regeneration, recruitment, cell replacement, therapy ■ Abstract New cells are continuously generated from immature proliferating cells throughout adulthood in many organs, thereby contributing to the integrity of the tissue under physiological conditions and to repair following injury. In contrast, repair mechanisms in the adult central nervous system (CNS) have long been thought to be very limited. However, recent findings have clearly demonstrated that in restricted areas of the mammalian brain, new functional neurons are constantly generated from neural stem cells throughout life. Moreover, stem cells with the potential to give rise to new neurons reside in many different regions of the adult CNS. These findings raise the possibility that endogenous neural stem cells can be mobilized to replace dying neurons in neurodegenerative diseases.
    [Show full text]
  • Broom Fish Brains Pain
    Pre-publication copy Broom, D.M. 2016. Fish brains and behaviour indicate capacity for feeling pain. Animal Sentience, 2016.010 (5 pages). Fish brains, as well as fish behaviour, indicate capacity for awareness and feeling pain Donald M. Broom Centre for Anthrozoology and Animal Welfare Department of Veterinary Medicine University of Cambridge Madingley Road Cambridge CB3 0ES U.K. [email protected] http://www.neuroscience.cam.ac.uk/directory/profile.php?dmb16 Keywords pain sentience welfare fish feelings emotions brain behaviour Abstract Studies of behaviour are of major importance in understanding human pain and pain in other animals such as fish. Almost all of the characteristics of the mammalian pain system are also described for fish. Emotions, feelings and learning from these are controlled in the fish brain in areas anatomically different but functionally very similar to those in mammals. The evidence of pain and fear system function in fish is so similar to that in humans and other mammals that it is logical to conclude that fish feel fear and pain. Fish are sentient beings. Key (2015) is scornful about evidence from studies of fish behaviour indicating that fish are aware and feel pain but presents a thorough explanation of the pain system in the human brain and concludes that fish could not feel pain, or have any other feelings, as they do not have the brain structures that allow pain and other feelings in humans. Section 2 of his paper emphasises “the cortical origins of human pain” and states that “structure determines function”, eXplaining the functions of the five layers of the human cortex.
    [Show full text]