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Chen YH, Chang CY, Yen NS, Tsai SY. Brain plasticity of structural connectivity networks and topological properties in baseball players with different levels of expertise. Brain Cogn 2023; 166:105943. [PMID: 36621186 DOI: 10.1016/j.bandc.2022.105943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 12/06/2022] [Accepted: 12/28/2022] [Indexed: 01/09/2023]
Abstract
Brain plasticity in structural connectivity networks along the development of expertise has remained largely unknown. To address this, we recruited individuals with three different levels of baseball-playing experience: skilled batters (SB), intermediate batters (IB), and healthy controls (HC). We constructed their structural connectivity networks using diffusion tractography and compared their region-to-region structural connections and the topological characteristics of the constructed networks using graph-theoretical analysis. The group differences were detected in 35 connections predominantly involving sensorimotor and visual systems; the intergroup changes could be depicted either in a stepwise (HC < / = IB < / = SB) or a U-/inverted U-shaped manner as experience increased (IB < SB and/or HC, or opposite). All groups showed small-world topology in their constructed networks, but SB had increased global and local network efficiency than IB and/or HC. Furthermore, although the number and cortical regions identified as hubs of the networks in the three groups were highly similar, SB exhibited higher nodal global efficiency in both the dorsolateral and medial parts of the bilateral superior frontal gyri than IB. Our findings add new evidence of topological reorganization in brain networks associated with sensorimotor experience in sports. Interestingly, these changes do not necessarily increase as a function of experience as previously suggested in literature.
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Affiliation(s)
- Yin-Hua Chen
- Graduate Institute of Athletics and Coaching Science, National Taiwan Sport University, No. 250, Wenhua 1st Rd, Guishan, Taoyuan 33301, Taiwan
| | - Chih-Yen Chang
- Department of Physical Education, National Taiwan Normal University, 162, Sec. 1, Heping E. Rd, Taipei 10610, Taiwan
| | - Nai-Shing Yen
- Research Center for Mind, Brain, and Learning, National Chengchi University, No. 64, Sec. 2, Zhi-Nan Rd, Wen-Shan District, Taipei 11605, Taiwan; Department of Psychology, National Chengchi University, No. 64, Sec. 2, Zhi-Nan Rd, Wen-Shan District, Taipei 11605, Taiwan.
| | - Shang-Yueh Tsai
- Research Center for Mind, Brain, and Learning, National Chengchi University, No. 64, Sec. 2, Zhi-Nan Rd, Wen-Shan District, Taipei 11605, Taiwan; Graduate Institute of Applied Physics, National Chengchi University, No. 64, Sec. 2, Zhi-Nan Rd, Wen-Shan District, Taipei 11605, Taiwan.
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Dalton MA, D'Souza A, Lv J, Calamante F. New insights into anatomical connectivity along the anterior–posterior axis of the human hippocampus using in vivo quantitative fibre tracking. eLife 2022; 11:76143. [PMID: 36345716 PMCID: PMC9643002 DOI: 10.7554/elife.76143] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 09/16/2022] [Indexed: 11/09/2022] Open
Abstract
The hippocampus supports multiple cognitive functions including episodic memory. Recent work has highlighted functional differences along the anterior–posterior axis of the human hippocampus, but the neuroanatomical underpinnings of these differences remain unclear. We leveraged track-density imaging to systematically examine anatomical connectivity between the cortical mantle and the anterior–posterior axis of the in vivo human hippocampus. We first identified the most highly connected cortical areas and detailed the degree to which they preferentially connect along the anterior–posterior axis of the hippocampus. Then, using a tractography pipeline specifically tailored to measure the location and density of streamline endpoints within the hippocampus, we characterised where these cortical areas preferentially connect within the hippocampus. Our results provide new and detailed insights into how specific regions along the anterior–posterior axis of the hippocampus are associated with different cortical inputs/outputs and provide evidence that both gradients and circumscribed areas of dense extrinsic anatomical connectivity exist within the human hippocampus. These findings inform conceptual debates in the field and emphasise the importance of considering the hippocampus as a heterogeneous structure. Overall, our results represent a major advance in our ability to map the anatomical connectivity of the human hippocampus in vivo and inform our understanding of the neural architecture of hippocampal-dependent memory systems in the human brain. The brain allows us to perceive and interact with our environment and to create and recall memories about our day-to-day lives. A sea-horse shaped structure in the brain, called the hippocampus, is critical for translating our perceptions into memories, and it does so in coordination with other brain regions. For example, different regions of the cerebral cortex (the outer layer of the brain) support different aspects of cognition, and pathways of information flow between the cerebral cortex and hippocampus underpin the healthy functioning of memory. Decades of research conducted into the brains of non-human primates show that specific regions of the cerebral cortex anatomically connect with different parts of the hippocampus to support this information flow. These insights form the foundation for existing theoretical models of how networks of neurons in the hippocampus and the cerebral cortex are connected. However, the human cerebral cortex has greatly expanded during our evolution, meaning that patterns of connectivity in the human brain may diverge from those in the brains of non-human primates. Deciphering human brain circuits in greater detail is crucial if we are to gain a better understanding of the structure and operation of the healthy human brain. However, obtaining comprehensive maps of anatomical connections between the hippocampus and cerebral cortex has been hampered by technical limitations. For example, magnetic resonance imaging (MRI), an approach that can be used to study the living human brain, suffers from insufficient image resolution. To overcome these issues, Dalton et al. used an imaging technique called diffusion weighted imaging which is used to study white matter pathways in the brain. They developed a tailored approach to create high-resolution maps showing how the hippocampus anatomically connects with the cerebral cortex in the healthy human brain. Dalton et al. produced detailed maps illustrating which areas of the cerebral cortex have high anatomical connectivity with the hippocampus and how different parts of the hippocampus preferentially connect to different neural circuits in the cortex. For example, the experiments demonstrate that highly connected areas in a cortical region called the temporal cortex connect to very specific, circumscribed regions within the hippocampus. These findings suggest that the hippocampus may consist of different neural circuits, each preferentially linked to defined areas of the cortex which are, in turn, associated with specific aspects of cognition. These observations further our knowledge of hippocampal-dependant memory circuits in the human brain and provide a foundation for the study of memory decline in aging and neurodegenerative diseases.
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Affiliation(s)
- Marshall A Dalton
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney
- Brain and Mind Centre, The University of Sydney
- School of Psychology, Faculty of Science, The University of Sydney
| | - Arkiev D'Souza
- Brain and Mind Centre, The University of Sydney
- Faculty of Medicine and Health Translational Research Collective, The University of Sydney
- Sydney Imaging, University of Sydney
| | - Jinglei Lv
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney
- Brain and Mind Centre, The University of Sydney
| | - Fernando Calamante
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney
- Brain and Mind Centre, The University of Sydney
- Sydney Imaging, University of Sydney
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Schottelkotte KM, Crone SA. Forebrain control of breathing: Anatomy and potential functions. Front Neurol 2022; 13:1041887. [PMID: 36388186 PMCID: PMC9663927 DOI: 10.3389/fneur.2022.1041887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 10/11/2022] [Indexed: 01/25/2023] Open
Abstract
The forebrain plays important roles in many critical functions, including the control of breathing. We propose that the forebrain is important for ensuring that breathing matches current and anticipated behavioral, emotional, and physiological needs. This review will summarize anatomical and functional evidence implicating forebrain regions in the control of breathing. These regions include the cerebral cortex, extended amygdala, hippocampus, hypothalamus, and thalamus. We will also point out areas where additional research is needed to better understand the specific roles of forebrain regions in the control of breathing.
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Affiliation(s)
- Karl M. Schottelkotte
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Steven A. Crone
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, OH, United States
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Shahsavari F, Abbasnejad M, Esmaeili-Mahani S, Raoof M. The ability of orexin-A to modify pain-induced cyclooxygenase-2 and brain-derived neurotrophic factor expression is associated with its ability to inhibit capsaicin-induced pulpal nociception in rats. Korean J Pain 2022; 35:261-270. [PMID: 35768981 PMCID: PMC9251390 DOI: 10.3344/kjp.2022.35.3.261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/30/2022] [Accepted: 04/08/2022] [Indexed: 11/26/2022] Open
Abstract
Background The rostral ventromedial medulla (RVM) is a critical region for the management of nociception. The RVM is also involved in learning and memory processes due to its relationship with the hippocampus. The purpose of the present study was to investigate the molecular mechanisms behind orexin-A signaling in the RVM and hippocampus’s effects on capsaicin-induced pulpal nociception and cognitive impairments in rats. Methods Capsaicin (100 g) was applied intradentally to male Wistar rats to induce inflammatory pulpal nociception. Orexin-A and an orexin-1 receptor antagonist (SB-334867) were then microinjected into the RVM. Immunoblotting and immunofluorescence staining were used to check the levels of cyclooxygenase-2 (COX-2) and brain-derived neurotrophic factor (BDNF) in the RVM and hippocampus. Results Interdental capsaicin treatment resulted in nociceptive responses as well as a reduction in spatial learning and memory. Additionally, it resulted in decreased BDNF and increased COX-2 expression levels. Orexin-A administration (50 pmol/1 μL/rat) could reverse such molecular changes. SB-334867 microinjection (80 nM/1 μL/rat) suppressed orexin’s effects. Conclusions Orexin-A signaling in the RVM and hippocampus modulates capsaicin-induced pulpal nociception in male rats by increasing BDNF expression and decreasing COX-2 expression.
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Affiliation(s)
- Fatemeh Shahsavari
- Department of Biology, Faculty of Sciences, Shahid Bahonar University, Kerman, Iran
| | - Mehdi Abbasnejad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University, Kerman, Iran
| | - Saeed Esmaeili-Mahani
- Department of Biology, Faculty of Sciences, Shahid Bahonar University, Kerman, Iran.,Neuroscience Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Maryam Raoof
- Academisch Centrum Tandheelkunde Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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Patodia S, Somani A, Thom M. Review: Neuropathology findings in autonomic brain regions in SUDEP and future research directions. Auton Neurosci 2021; 235:102862. [PMID: 34411885 PMCID: PMC8455454 DOI: 10.1016/j.autneu.2021.102862] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 07/16/2021] [Accepted: 07/24/2021] [Indexed: 12/21/2022]
Abstract
Autonomic dysfunction is implicated from clinical, neuroimaging and experimental studies in sudden and unexpected death in epilepsy (SUDEP). Neuropathological analysis in SUDEP series enable exploration of acquired, seizure-related cellular adaptations in autonomic and brainstem autonomic centres of relevance to dysfunction in the peri-ictal period. Alterations in SUDEP compared to control groups have been identified in the ventrolateral medulla, amygdala, hippocampus and central autonomic regions. These involve neuropeptidergic, serotonergic and adenosine systems, as well as specific regional astroglial and microglial populations, as potential neuronal modulators, orchestrating autonomic dysfunction. Future research studies need to extend to clinically and genetically characterized epilepsies, to explore if common or distinct pathways of autonomic dysfunction mediate SUDEP. The ultimate objective of SUDEP research is the identification of disease biomarkers for at risk patients, to improve post-mortem recognition and disease categorisation, but ultimately, for exposing potential treatment targets of pharmacologically modifiable and reversible cellular alterations.
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Affiliation(s)
- Smriti Patodia
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
| | - Alyma Somani
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
| | - Maria Thom
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK.
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Somani A, El-Hachami H, Patodia S, Sisodiya S, Thom M. Regional microglial populations in central autonomic brain regions in SUDEP. Epilepsia 2021; 62:1318-1328. [PMID: 33942290 DOI: 10.1111/epi.16904] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/28/2021] [Accepted: 03/29/2021] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Sudden unexpected death in epilepsy (SUDEP) may arise as a result of autonomic dysfunction during a seizure. The central autonomic networks (CANs) modulate brainstem cardiorespiratory regulation. Recent magnetic resonance imaging (MRI) studies in SUDEP have shown cortical and subcortical volume changes and altered connectivity between CAN regions, but the pathological correlate is unknown. Because neuroinflammation is both a cause and a consequence of seizures and may relate to regional brain pathology, our aim was to evaluate microglial populations in CANs in SUDEP. METHODS In 55 postmortem cases, including SUDEP, epilepsy controls without SUDEP and nonepilepsy controls, we quantified Iba1-expressing microglia in 14 cortical and thalamic areas that included known CAN regions. RESULTS Mean Iba1 labeling across all brain regions was significantly higher in SUDEP cases compared to epilepsy and nonepilepsy controls. There was significant regional variation in Iba1 labeling in SUDEP cases only, with highest labeling in the medial thalamus. Significantly higher labeling in SUDEP cases than epilepsy and nonepilepsy controls was consistently noted in the superior temporal gyrus. In cases with documented seizures up to 10 days prior to death, significantly higher mean Iba1 labeling was observed in SUDEP compared to epilepsy controls. SIGNIFICANCE Our findings support microglial activation in SUDEP, including cortical and subcortical regions with known autonomic functions such as the thalamus and superior temporal gyrus. This may be relevant to cellular pathomechanisms underlying cardioregulatory failure during a seizure.
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Affiliation(s)
- Alyma Somani
- Departments of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Hanna El-Hachami
- Departments of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Smriti Patodia
- Departments of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Sanjay Sisodiya
- Departments of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Bucks, UK
| | - Maria Thom
- Departments of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Neuropathology, National Hospital for Neurology and Neurosurgery Queen Square, London, UK
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Zakharova EI, Storozheva ZI, Proshin AT, Monakov MY, Dudchenko AM. Opposite Pathways of Cholinergic Mechanisms of Hypoxic Preconditioning in the Hippocampus: Participation of Nicotinic α7 Receptors and Their Association with the Baseline Level of Startle Prepulse Inhibition. Brain Sci 2020; 11:brainsci11010012. [PMID: 33374246 PMCID: PMC7824639 DOI: 10.3390/brainsci11010012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/15/2020] [Accepted: 12/21/2020] [Indexed: 12/14/2022] Open
Abstract
(1) Background. A one-time moderate hypobaric hypoxia (HBH) has a preconditioning effect whose neuronal mechanisms are not studied well. Previously, we found a stable correlation between the HBH efficiency and acoustic startle prepulse inhibition (PPI). This makes it possible to predict the individual efficiency of HBH in animals and to study its potential adaptive mechanisms. We revealed a bi-directional action of nicotinic α7 receptor agonist PNU-282987 and its solvent dimethyl sulfoxide on HBH efficiency with the level of PPI > or < 40%. (2) The aim of the present study was to estimate cholinergic mechanisms of HBH effects in different brain regions. (3) Methods: in rats pretested for PPI, we evaluated the activity of synaptic membrane-bound and water-soluble choline acetyltransferase (ChAT) in the sub-fractions of ‘light’ and ‘heavy’ synaptosomes of the neocortex, hippocampus and caudal brainstem in the intact brain and after HBH. We tested the dose-dependent influence of PNU-282987 on the HBH efficiency. (4) Results: PPI level and ChAT activity correlated negatively in all brain structures of the intact animals, so that the values of the latter were higher in rats with PPI < 40% compared to those with PPI > 40%. After HBH, this ChAT activity difference was leveled in the neocortex and caudal brainstem, while for membrane-bound ChAT in the ‘light’ synaptosomal fraction of hippocampus, it was reversed to the opposite. In addition, a pharmacological study revealed that PNU-282987 in all used doses and its solvent displayed corresponding opposite effects on HBH efficiency in rats with different levels of PPI. (5) Conclusion: We substantiate that in rats with low and high PPI two opposite hippocampal cholinergic mechanisms are involved in hypoxic preconditioning, and both are implemented by forebrain projections via nicotinic α7 receptors. Possible causes of association between general protective adaptation, HBH, PPI, forebrain cholinergic system and hippocampus are discussed.
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Affiliation(s)
- Elena I. Zakharova
- Laboratory of General Pathology of Cardiorespiratory System, Institute of General Pathology and Pathophysiology, Baltiyskaya, 8, 125315 Moscow, Russia; (M.Y.M.); (A.M.D.)
- Correspondence: ; Tel.: +7-9199668657; Fax: +7-4991511756
| | - Zinaida I. Storozheva
- Laboratory of Clinical Neurophysiology, Serbsky’ National Medical Research Center for Psychiatry and Narcology, Kropotkinsky per., 23, 111395 Moscow, Russia;
| | - Andrey T. Proshin
- Laboratory of Functional Neurochemistry, P.K. Anokhin Institute of Normal Physiology, Baltiyskaya, 8, 125315 Moscow, Russia;
| | - Mikhail Yu. Monakov
- Laboratory of General Pathology of Cardiorespiratory System, Institute of General Pathology and Pathophysiology, Baltiyskaya, 8, 125315 Moscow, Russia; (M.Y.M.); (A.M.D.)
| | - Alexander M. Dudchenko
- Laboratory of General Pathology of Cardiorespiratory System, Institute of General Pathology and Pathophysiology, Baltiyskaya, 8, 125315 Moscow, Russia; (M.Y.M.); (A.M.D.)
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Somani A, Zborovschi AB, Liu Y, Patodia S, Michalak Z, Sisodiya SM, Thom M. Hippocampal morphometry in sudden and unexpected death in epilepsy. Neurology 2019; 93:e804-e814. [PMID: 31345959 DOI: 10.1212/wnl.0000000000007969] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 04/01/2019] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE To determine hippocampal morphometric measures, including granule cell dispersion and features of malrotation, as potential biomarkers for sudden unexpected death in epilepsy (SUDEP) from an archival postmortem series. METHODS In a retrospective study of 187 archival postmortems from 3 groups, SUDEP (68; 14 with hippocampal sclerosis [HS]), non-SUDEP epilepsy controls (EP-C = 66; 25 with HS), and nonepilepsy controls (NEC = 53), Nissl/hematoxylin & eosin-stained sections from left and right hippocampus from 5 coronal levels were digitized. Image analysis was carried out for granule cell layer (GCL) thickness and measurements of hippocampal dimensions (HD) for shape (width [HD1], height [HD2]) and medial hippocampal positioning in relation to the parahippocampal gyrus (PHG) length (HD3). A qualitative evaluation of hippocampal malrotational (HMAL) features, dentate gyrus invaginations (DGI), and subicular/CA1 folds (SCF) was also made. RESULTS GCL thickness was increased in HS more than those without (p < 0.001). In non-HS cases, increased GCL thickness was noted in EP-C compared to NEC (p < 0.05) but not between SUDEP and NEC. There was no difference in the frequency of DGI, SCF, measurements of hippocampal shape (HD1, HD2, or ratio), or medial positioning among SUDEP, EP-C, and NEC groups, when factoring in HS, coronal level, and age at death. Comparison between left and right sides within cases showed greater PHG lengths (HD3) on the right side in the SUDEP group only (p = 0.018). CONCLUSIONS No hippocampal morphometric features were identified in support of either excessive granule cell dispersion or features of HMAL as definitive biomarkers for SUDEP. Asymmetries in PHG measurements in SUDEP warrant further investigation as they may indicate abnormal central autonomic networks.
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Affiliation(s)
- Alyma Somani
- From the Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Anita-Beatrix Zborovschi
- From the Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Yan Liu
- From the Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Smriti Patodia
- From the Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Zuzanna Michalak
- From the Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Sanjay M Sisodiya
- From the Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Maria Thom
- From the Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK.
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Revealing the Hippocampal Connectome through Super-Resolution 1150-Direction Diffusion MRI. Sci Rep 2019; 9:2418. [PMID: 30787303 PMCID: PMC6382767 DOI: 10.1038/s41598-018-37905-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 12/15/2018] [Indexed: 12/21/2022] Open
Abstract
The hippocampus is a key component of emotional and memory circuits and is broadly connected throughout the brain. We tracked the whole-brain connections of white matter fibres from the hippocampus using ultra-high angular resolution diffusion MRI in both a single 1150-direction dataset and a large normal cohort (n = 94; 391-directions). Using a connectomic approach, we identified six dominant pathways in terms of strength, length and anatomy, and characterised them by their age and gender variation. The strongest individual connection was to the ipsilateral thalamus. There was a strong age dependence of hippocampal connectivity to medial occipital regions. Overall, our results concur with preclinical and ex-vivo data, confirming that meaningful in vivo characterisation of hippocampal connections is possible in an individual. Our findings extend the collective knowledge of hippocampal anatomy, highlighting the importance of the spinal-limbic pathway and the striking lack of hippocampal connectivity with motor and sensory cortices.
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Kooshki R, Abbasnejad M, Esmaeili-Mahani S, Raoof M. The effect of CA1 administration of orexin-A on hippocampal expression of COX-2 and BDNF in a rat model of orofacial pain. ARQUIVOS DE NEURO-PSIQUIATRIA 2018; 76:603-608. [DOI: 10.1590/0004-282x20180099] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 06/12/2018] [Indexed: 11/22/2022]
Abstract
ABSTRACT The neuropeptide orexin-A and its receptors are widely distributed in both hippocampal circuitry and pain transmission pathways. Objective: Involvement of the CA1 orexin 1 receptor (OX1R) on the modulation of orofacial pain and pain-induced changes in hippocampal expression of cyclooxygenase-2 (COX-2) and brain-derived neurotrophic factor (BDNF) was investigated. Methods: Orofacial pain was induced by an intra-lip injection of capsaicin (100 μg). Reverse transcription polymerase chain reaction and immunoblot analysis were used to indicate changes in hippocampal BDNF and COX-2 expression, respectively. Results: Capsaicin induces a significant pain response, which is not affected by either orexin-A or SB-334867-A, an OX1R antagonist. However, an increased expression of COX-2 and decreased expression of BDNF was observed in the hippocampus of animals that received capsaicin or SB-334867-A (80 nM) plus capsaicin. Meanwhile, orexin-A (40 pM) attenuated the effects of capsaicin on the expression of COX-2 and BDNF. Conclusions: CA1 OX1R activation moderates capsaicin-induced neuronal inflammation and neurotrophic deficiency.
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Affiliation(s)
| | | | | | - Maryam Raoof
- Kerman University of Medical Sciences, Iran; Kerman University of Medical Sciences, Iran
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Ajayi IE, McGovern AE, Driessen AK, Kerr NF, Mills PC, Mazzone SB. Hippocampal modulation of cardiorespiratory function. Respir Physiol Neurobiol 2018; 252-253:18-27. [PMID: 29550518 DOI: 10.1016/j.resp.2018.03.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/19/2018] [Accepted: 03/07/2018] [Indexed: 02/07/2023]
Abstract
Changes in cardiorespiratory control accompany the expression of complex emotions, indicative of limbic brain inputs onto bulbar autonomic pathways. Previous studies have focussed on the role of the prefrontal cortex in autonomic regulation. However, the role of the hippocampus, also important in limbic processing, has not been addressed in detail. Anaesthetised, instrumented rats were used to map the location of hippocampal sites capable of evoking changes in cardiorespiratory control showing that stimulation of discrete regions within the CA1 fields of both the dorsal and ventral hippocampus potently alter breathing and cardiovascular activity. Additionally, tracing of the neuroanatomical tracts and pharmacological inactivation studies were used to demonstrate a role of the basomedial amygdala in hippocampal evoked responses. Collectively, these data support the existence of a hippocampal-amygdala neural circuit capable of modulating bulbar cardiorespiratory control networks and may suggest a role for this circuit in the top-down regulation of breathing and autonomic outflow necessary for the expression of complex emotions.
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Affiliation(s)
- Itopa E Ajayi
- School of Veterinary Science, The University of Queensland, Gatton, QLD, 4343, Australia.
| | - Alice E McGovern
- The Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Alexandria K Driessen
- The Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Nicole F Kerr
- The Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Paul C Mills
- School of Veterinary Science, The University of Queensland, Gatton, QLD, 4343, Australia.
| | - Stuart B Mazzone
- The Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, 3010, Australia.
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