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Higo N. Motor Cortex Plasticity During Functional Recovery Following Brain Damage. JOURNAL OF ROBOTICS AND MECHATRONICS 2022. [DOI: 10.20965/jrm.2022.p0700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although brain damage causes functional impairment, it is often followed by partial or total recovery of function. Recovery is believed to occur primarily because of brain plasticity. Both human and animal studies have significantly contributed to uncovering the neuronal basis of plasticity. Recent advances in brain imaging technology have enabled the investigation of plastic changes in living human brains. In addition, animal experiments have revealed detailed changes at the neural and genetic levels. In this review, plasticity in motor-related areas of the cerebral cortex, which is one of the most well-studied areas of the neocortex in terms of plasticity, is reviewed. In addition, the potential of technological interventions to enhance plasticity and promote functional recovery following brain damage is discussed. Novel neurorehabilitation technologies are expected to be established based on the emerging research on plasticity from the last several decades.
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Lotfi M, Hasanpour AH, Moghadamnia AA, Kazemi S. The Investigation into Neurotoxicity Mechanisms of Nonylphenol: A Narrative Review. Curr Neuropharmacol 2021; 19:1345-1353. [PMID: 33213348 PMCID: PMC8719294 DOI: 10.2174/1570159x18666201119160347] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 10/07/2020] [Accepted: 10/14/2020] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Nonylphenol (NP), a chemical compound widely used in industry, is the result of the nonylphenol ethoxylate decomposition and it is known as an estrogen-like compound. Numerous studies and researches have shown that it has many destructive functions of various organs such as the brain. This toxicant causes oxidative stress in the cortex and hippocampus cells, which are two essential regions to preserve memory and learning in the brain. METHODS This review examines recent findings to better understanding the mechanisms of NP neurotoxicity. We used Scopus, Google Scholar, and PubMed databases to find articles focused on the destructive effects of NP on the oxidative stress pathway and its defense mechanisms. RESULTS NP has potential human health hazards associated with gestational, peri- and postnatal exposure. NP can disrupt brain homeostasis in different ways, such as activation of inflammatory factors in brain especially in hippocampus and cortex, disruption of the cell cycle, changes in neuron, dendrites and synapses morphology, disruption of extra and intracellular calcium ion balance and also memory and learning disorders.
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Affiliation(s)
| | | | | | - Sohrab Kazemi
- Address correspondence to this author at the Cellular and Molecular Biology Research Center, Health Research Center, Babol University of Medical Sciences, Babol, Iran, Tel: +98.9111162119; Fax: +98.1132207918; E-mail:
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Nazir FH, Becker B, Brinkmalm A, Höglund K, Sandelius Å, Bergström P, Satir TM, Öhrfelt A, Blennow K, Agholme L, Zetterberg H. Expression and secretion of synaptic proteins during stem cell differentiation to cortical neurons. Neurochem Int 2018; 121:38-49. [PMID: 30342961 PMCID: PMC6232556 DOI: 10.1016/j.neuint.2018.10.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/01/2018] [Accepted: 10/17/2018] [Indexed: 11/23/2022]
Abstract
Synaptic function and neurotransmitter release are regulated by specific proteins. Cortical neuronal differentiation of human induced pluripotent stem cells (hiPSC) provides an experimental model to obtain more information about synaptic development and physiology in vitro. In this study, expression and secretion of the synaptic proteins, neurogranin (NRGN), growth-associated protein-43 (GAP-43), synaptosomal-associated protein-25 (SNAP-25) and synaptotagmin-1 (SYT-1) were analyzed during cortical neuronal differentiation. Protein levels were measured in cells, modeling fetal cortical development and in cell-conditioned media which was used as a model of cerebrospinal fluid (CSF), respectively. Human iPSC-derived cortical neurons were maintained over a period of at least 150 days, which encompasses the different stages of neuronal development. The differentiation was divided into the following stages: hiPSC, neuro-progenitors, immature and mature cortical neurons. We show that NRGN was first expressed and secreted by neuro-progenitors while the maximum was reached in mature cortical neurons. GAP-43 was expressed and secreted first by neuro-progenitors and its expression increased markedly in immature cortical neurons. SYT-1 was expressed and secreted already by hiPSC but its expression and secretion peaked in mature neurons. SNAP-25 was first detected in neuro-progenitors and the expression and secretion increased gradually during neuronal stages reaching a maximum in mature neurons. The sensitive analytical techniques used to monitor the secretion of these synaptic proteins during cortical development make these data unique, since the secretion of these synaptic proteins has not been investigated before in such experimental models. The secretory profile of synaptic proteins, together with low release of intracellular content, implies that mature neurons actively secrete these synaptic proteins that previously have been associated with neurodegenerative disorders, including Alzheimer's disease. These data support further studies of human neuronal and synaptic development in vitro, and would potentially shed light on the mechanisms underlying altered concentrations of the proteins in bio-fluids in neurodegenerative diseases.
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Affiliation(s)
- Faisal Hayat Nazir
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, S-405 30, Gothenburg, Sweden; Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, S-431 80, Mölndal, Sweden.
| | - Bruno Becker
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, S-431 80, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, S-431 80, Mölndal, Sweden
| | - Ann Brinkmalm
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, S-431 80, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, S-431 80, Mölndal, Sweden
| | - Kina Höglund
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, S-431 80, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, S-431 80, Mölndal, Sweden
| | - Åsa Sandelius
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, S-431 80, Mölndal, Sweden
| | - Petra Bergström
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, S-405 30, Gothenburg, Sweden
| | - Tugce Munise Satir
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, S-405 30, Gothenburg, Sweden
| | - Annika Öhrfelt
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, S-431 80, Mölndal, Sweden
| | - Kaj Blennow
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, S-431 80, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, S-431 80, Mölndal, Sweden
| | - Lotta Agholme
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, S-405 30, Gothenburg, Sweden
| | - Henrik Zetterberg
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, S-431 80, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, S-431 80, Mölndal, Sweden; UCL, Institute of Neurology, Department of Neurodegerative Disease, University College London, Queen Square, London, WC1N 3BG, UK; UK Dementia Research Institute at UCL, London, WC1N 3BG, UK
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Nagasaka K, Takashima I, Matsuda K, Higo N. Late-onset hypersensitivity after a lesion in the ventral posterolateral nucleus of the thalamus: A macaque model of central post-stroke pain. Sci Rep 2017; 7:10316. [PMID: 28871156 PMCID: PMC5583363 DOI: 10.1038/s41598-017-10679-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 08/14/2017] [Indexed: 01/15/2023] Open
Abstract
Central post-stroke pain (CPSP) can occur as a result of a cerebrovascular accident in the ventral posterolateral nucleus (VPL) of the thalamus. Developing therapeutic interventions for CPSP is difficult because its pathophysiology is unclear. Here we developed and characterized a macaque model of CPSP. The location of the VPL was determined by magnetic resonance imaging (MRI) and extracellular recording of neuronal activity during tactile stimulation, after which a hemorrhagic lesion was induced by injecting collagenase type IV. Histological analysis revealed that most of the lesion was localized within the VPL. Several weeks after the injection, the macaques displayed behavioral changes that were interpreted as reflecting the development of both mechanical allodynia and thermal hyperalgesia. Immunohistochemistry revealed that microglial and astrocytic activation in the perilesional areas lasted at least 3 months after injection. The present model reproduced the symptoms of patients suffering from CPSP, in which both mechanical allodynia and thermal hyperalgesia often develop several weeks after cerebrovascular accident. Further, the long-lasting glial activation revealed here may be characteristic of primate brains following injury. The present model will be useful not only for examining the neurological changes underlying CPSP, but also for testing therapeutic interventions for CPSP.
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Affiliation(s)
- Kazuaki Nagasaka
- Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8568, Japan.,Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan
| | - Ichiro Takashima
- Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8568, Japan.,Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan
| | - Keiji Matsuda
- Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8568, Japan
| | - Noriyuki Higo
- Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8568, Japan.
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Caprara GA, Morabito C, Perni S, Navarra R, Guarnieri S, Mariggiò MA. Evidence for Altered Ca 2+ Handling in Growth Associated Protein 43-Knockout Skeletal Muscle. Front Physiol 2016; 7:493. [PMID: 27833566 PMCID: PMC5080375 DOI: 10.3389/fphys.2016.00493] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/11/2016] [Indexed: 11/13/2022] Open
Abstract
Neuronal growth-associated protein 43 (GAP43) has crucial roles in the nervous system, and during development, regeneration after injury, and learning and memory. GAP43 is expressed in mouse skeletal muscle fibers and satellite cells, with suggested its involvement in intracellular Ca2+ handling. However, the physiological role of GAP43 in muscle remains unknown. Using a GAP43-knockout (GAP43-/-) mouse, we have defined the role of GAP43 in skeletal muscle. GAP43-/- mice showed low survival beyond weaning, reduced adult body weight, decreased muscle strength, and changed myofiber ultrastructure, with no significant differences in the expression of markers of satellite cell and myotube progression through the myogenic program. Thus, GAP43 expression is involved in timing of muscle maturation in-vivo. Intracellular Ca2+ measurements in-vitro in myotubes revealed GAP43 involvement in Ca2+ handling. In the absence of GAP43 expression, the spontaneous Ca2+ variations had greater amplitudes and higher frequency. In GAP43-/- myotubes, also the intracellular Ca2+ variations induced by the activation of dihydropyridine and ryanodine Ca2+ channels, resulted modified. These evidences suggested dysregulation of Ca2+ homeostasis. The emerging hypothesis indicates that GAP43 interacts with calmodulin to indirectly modulate the activities of dihydropyridine and ryanodine Ca2+ channels. This thus influences intracellular Ca2+ dynamics and its related intracellular patterns, from functional excitation-contraction coupling, to cell metabolism, and gene expression.
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Affiliation(s)
- Giusy A Caprara
- Laboratory of Functional Biotechnology, Center of Sciences on Aging and Translational Medicine (CeSI-MeT), Department of Neuroscience, Imaging and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara Chieti, Italy
| | - Caterina Morabito
- Laboratory of Functional Biotechnology, Center of Sciences on Aging and Translational Medicine (CeSI-MeT), Department of Neuroscience, Imaging and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara Chieti, Italy
| | - Stefano Perni
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania Philadelphia, PA, USA
| | - Riccardo Navarra
- Department of Neuroscience, Imaging and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara Chieti, Italy
| | - Simone Guarnieri
- Laboratory of Functional Biotechnology, Center of Sciences on Aging and Translational Medicine (CeSI-MeT), Department of Neuroscience, Imaging and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara Chieti, Italy
| | - Maria A Mariggiò
- Laboratory of Functional Biotechnology, Center of Sciences on Aging and Translational Medicine (CeSI-MeT), Department of Neuroscience, Imaging and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara Chieti, Italy
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Murata Y, Higo N, Oishi T, Isa T. Increased expression of the growth-associated protein-43 gene after primary motor cortex lesion in macaque monkeys. Neurosci Res 2015; 98:64-9. [PMID: 25959053 DOI: 10.1016/j.neures.2015.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/25/2015] [Accepted: 04/27/2015] [Indexed: 10/23/2022]
Abstract
We recently showed that changes of brain activity in the ipsilesional ventral premotor cortex (PMv) and perilesional primary motor cortex (M1) of macaque monkeys were responsible for recovery of manual dexterity after lesioning M1. To investigate whether axonal remodeling is associated with M1 lesion-induced changes in brain activity, we assessed gene expression of growth-associated protein-43 (GAP-43) in motor and premotor cortices. Increased expression was observed in the PMv during the period just after recovery and in the perilesional M1 during the plateau phase of recovery. Time-dependent and brain region-specific remodeling may play a role in functional recovery after lesioning M1.
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Affiliation(s)
- Yumi Murata
- Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Umezono, Tsukuba, Ibaraki 305-8568, Japan
| | - Noriyuki Higo
- Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Umezono, Tsukuba, Ibaraki 305-8568, Japan; Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan.
| | - Takao Oishi
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan; Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, Kanrin, Inuyama, Aichi 484-8506, Japan
| | - Tadashi Isa
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan; Department of Developmental Physiology, National Institute for Physiological Sciences (NIPS), Okazaki, Aichi 444-8585, Japan
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Abstract
Cerebral injury, such as stroke, cause functional deficits; however some functions can recover with postlesion rehabilitative training. Several recent studies using rodents and monkeys have reported the effects of postlesion training on functional recovery after brain injury. We present herein an overview of recent animal experimental studies on the effects of postlesion motor training on brain plasticity and motor recovery. Our study in the macaque monkey reported the effects of hand motor training on motor recovery after lesioning of the primary motor cortex (M1). In monkeys that had undergone intensive daily training after the lesion, manual dexterity recovered to previous levels. Relatively independent digit movements, including those of precision grip, were restored in the trained monkeys. While hand movements recovered to some extent in the monkeys without postlesion training, these monkeys frequently used alternative grips to grasp a small object instead o f the precision grip. These findings suggest that recovery after M1 lesions includes both training-dependent and training-independent processes, and that recovery of precision grip requires intensive postlesion training. Recent results of both brain imaging and gene expression analyses suggest that functional and structural changes may occur in uninjured motor areas during recovery of hand function after M1 lesions. In particular, our preliminary results suggest that structural changes in ventral premotor cortex neurons may participate in functional compensation of precision grip.
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Higo N, Nishimura Y, Murata Y, Oishi T, Yoshino-Saito K, Takahashi M, Tsuboi F, Isa T. Increased expression of the growth-associated protein 43 gene in the sensorimotor cortex of the macaque monkey after lesioning the lateral corticospinal tract. J Comp Neurol 2009; 516:493-506. [DOI: 10.1002/cne.22121] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Higo N, Oishi T, Yamashita A, Murata Y, Matsuda K, Hayashi M. Expression of protein kinase-C substrate mRNA in the motor cortex of adult and infant macaque monkeys. Brain Res 2007; 1171:30-41. [PMID: 17761152 DOI: 10.1016/j.brainres.2007.07.054] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Revised: 07/24/2007] [Accepted: 07/24/2007] [Indexed: 10/23/2022]
Abstract
To understand the molecular and cellular bases of plasticity in the primate motor cortex, we investigated the expression of three protein kinase-C (PKC) substrates: GAP-43, myristoylated alanine-rich C-kinase substrate (MARCKS), and neurogranin, which are key molecules regulating synaptic plasticity. Prominent signals for the three mRNAs were primarily observed in pyramidal cells. Large pyramidal cells in layer V, from which the descending motor tract originates, contained weaker hybridization signals for GAP-43 and neurogranin mRNAs than did the smaller pyramidal cells. We also performed double-label in situ hybridization showing that GAP-43 and neurogranin mRNAs were expressed in a subset of MARCKS-positive neurons. Quantitative analysis showed that the expression was different between the layers: layer VI contained the strongest and layer II the weakest signals for all three mRNAs. The expression levels of GAP-43 and MARCKS mRNA in layer V were higher than in layer III, while the expression level of neurogranin mRNA in layer V was almost the same as in layer III. Developmental analysis from the newborn to adult indicated that the expression levels of the three mRNAs were higher in the infant motor cortex than in the adult. The expression of both GAP-43 and neurogranin mRNAs transiently increased over several months postnatally. The present study showed that the expression of the three PKC substrates was specific to cell types, cortical layers, and postnatal developmental stage. The specific expression may reflect functional specialization for plasticity in the motor cortex of both infants and adults.
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Affiliation(s)
- Noriyuki Higo
- Neuroscience Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Umezono, Tsukuba, Ibaraki, Japan.
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Higo N, Oishi T, Yamashita A, Murata Y, Matsuda K, Hayashi M. Northern blot and in situ hybridization analyses for the neurogranin mRNA in the developing monkey cerebral cortex. Brain Res 2006; 1078:35-48. [PMID: 16497282 DOI: 10.1016/j.brainres.2006.01.062] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2005] [Revised: 01/03/2006] [Accepted: 01/08/2006] [Indexed: 11/22/2022]
Abstract
Neurogranin is a postsynaptic substrate for protein kinase C, and its expression is related to dendritic spine development and postsynaptic plasticity. Using both Northern blot analysis and in situ hybridization techniques, we investigated the developmental changes of neurogranin expression in the monkey cerebral cortex. In each of four neocortical areas examined, i.e., the prefrontal area (area FD of von Bonin and Bailey), the temporal association area (TE), the primary somatosensory area (PB), and the primary visual area (OC), the Northern blot analysis showed that the amount of neurogranin mRNA was low during the prenatal and perinatal periods until postnatal day 8. It increased during postnatal development and reached its peak value at postnatal day 70 (in area OC) or postnatal month 6 (in area FD, TE, and PB). After that, the amount of neurogranin mRNA in the cerebral neocortex decreased gradually until postnatal years 2-3. The in situ hybridization experiments also showed a transient increase of neurogranin mRNA in the neocortex during postnatal day 70 to postnatal month 6. The transient increase was prominent in layers II and III of areas FD and TE; deep in layer III of area PB; and in layers II, III, and IV of area OC. In the hippocampus, in contrast to the results in the neocortex, the expression of neurogranin mRNA was decreased almost continuously during the postnatal period. The transiently increased expression of neurogranin in the postnatal neocortex may be a molecular basis for the postsynaptic modification of afferent inputs possibly from subcortical structures.
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Affiliation(s)
- Noriyuki Higo
- Neuroscience Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Umezono, Tsukuba, Ibaraki 305-8568, Japan.
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Higo N, Oishi T, Yamashita A, Murata Y, Matsuda K, Hayashi M. Expression of protein kinase C-substrate mRNAs in the basal ganglia of adult and infant macaque monkeys. J Comp Neurol 2006; 499:662-76. [PMID: 17029258 DOI: 10.1002/cne.21119] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We performed in situ hybridization histochemistry on the monkey basal ganglia to investigate the mRNA localization of three protein kinase C substrates (GAP-43, MARCKS, and neurogranin), of which expression plays a role in structural changes in neurites and synapses. Weak hybridization signals for GAP-43 mRNA and intense signals for both MARCKS and neurogranin mRNAs were observed in the adult neostriatum. All three of the mRNAs were expressed in both substance P-positive direct pathway neurons and enkephalin-positive indirect pathway neurons. In the nucleus accumbens, the hybridization signals for the three mRNAs were weaker than those in the neostriatum. Double-label in situ hybridization histochemistry in the neostriatum revealed that GAP-43 and neurogranin mRNAs were expressed in a subset of MARCKS-positive neurons. While intense hybridization signals for MARCKS mRNA were observed in all of the other basal ganglia regions such as the globus pallidus, substantia innominata, subthalamic nucleus, and substantia nigra, intense signals for GAP-43 mRNA were restricted to the substantia innominata and substantia nigra pars compacta. No signal for neurogranin mRNA was observed in the basal ganglia regions outside the neostriatum and the nucleus accumbens. These results indicate that the protein kinase C substrates are abundant in some specific connections in cortico-basal ganglia circuits. Developmental analysis showed that the expression level in the putamen and nucleus accumbens, but not in the caudate nucleus, was higher in the infant than in the adult, suggesting that synaptic maturation in the caudate nucleus occurs earlier than that in the putamen and nucleus accumbens.
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Affiliation(s)
- Noriyuki Higo
- Neuroscience Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki 305-8568, Japan.
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