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Aquiles A, Fiordelisio T, Luna-Munguia H, Concha L. Altered functional connectivity and network excitability in a model of cortical dysplasia. Sci Rep 2023; 13:12335. [PMID: 37518675 PMCID: PMC10387479 DOI: 10.1038/s41598-023-38717-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 07/13/2023] [Indexed: 08/01/2023] Open
Abstract
Focal cortical dysplasias (FCDs) are malformations of cortical development that often result in medically refractory epilepsy, with a greater incidence in the pediatric population. The relationship between the disturbed cortical morphology and epileptogenic activity of FCDs remains unclear. We used the BCNU (carmustine 1-3-bis-chloroethyl-nitrosourea) animal model of cortical dysplasia to evaluate neuronal and laminar alterations and how these result in altered activity of intracortical networks in early life. We corroborated the previously reported morphological anomalies characteristic of the BCNU model, comprising slightly larger and rounder neurons and abnormal cortical lamination. Next, the neuronal activity of live cortical slices was evaluated through large field-of-view calcium imaging as well as the neuronal response to a stimulus that leads to cortical hyperexcitability (pilocarpine). Examination of the joint activity of neuronal calcium time series allowed us to identify intracortical communication patterns and their response to pilocarpine. The baseline power density distribution of neurons in the cortex of BCNU-treated animals was different from that of control animals, with the former showing no modulation after stimulus. Moreover, the intracortical communication pattern differed between the two groups, with cortexes from BCNU-treated animals displaying decreased inter-layer connectivity as compared to control animals. Our results indicate that the altered anatomical organization of the cortex of BCNU-treated rats translates into altered functional networks that respond abnormally to a hyperexcitable stimulus and highlight the role of network dysfunction in the pathophysiology of cortical dysplasia.
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Affiliation(s)
- A Aquiles
- Institute of Neurobiology, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, Querétaro, Mexico
| | - T Fiordelisio
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Laboratorio Nacional de Soluciones Biomiméticas para Diagnóstico y Terapia LaNSBioDyT, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - H Luna-Munguia
- Institute of Neurobiology, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, Querétaro, Mexico
| | - L Concha
- Institute of Neurobiology, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, Querétaro, Mexico.
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Villaseñor PJ, Cortés-Servín D, Pérez-Moriel A, Aquiles A, Luna-Munguía H, Ramirez-Manzanares A, Coronado-Leija R, Larriva-Sahd J, Concha L. Multi-tensor diffusion abnormalities of gray matter in an animal model of cortical dysplasia. Front Neurol 2023; 14:1124282. [PMID: 37342776 PMCID: PMC10278582 DOI: 10.3389/fneur.2023.1124282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 04/18/2023] [Indexed: 06/23/2023] Open
Abstract
Focal cortical dysplasias are a type of malformations of cortical development that are a common cause of drug-resistant focal epilepsy. Surgical treatment is a viable option for some of these patients, with their outcome being highly related to complete surgical resection of lesions visible in magnetic resonance imaging (MRI). However, subtle lesions often go undetected on conventional imaging. Several methods to analyze MRI have been proposed, with the common goal of rendering subtle cortical lesions visible. However, most image-processing methods are targeted to detect the macroscopic characteristics of cortical dysplasias, which do not always correspond to the microstructural disarrangement of these cortical malformations. Quantitative analysis of diffusion-weighted MRI (dMRI) enables the inference of tissue characteristics, and novel methods provide valuable microstructural features of complex tissue, including gray matter. We investigated the ability of advanced dMRI descriptors to detect diffusion abnormalities in an animal model of cortical dysplasia. For this purpose, we induced cortical dysplasia in 18 animals that were scanned at 30 postnatal days (along with 19 control animals). We obtained multi-shell dMRI, to which we fitted single and multi-tensor representations. Quantitative dMRI parameters derived from these methods were queried using a curvilinear coordinate system to sample the cortical mantle, providing inter-subject anatomical correspondence. We found region- and layer-specific diffusion abnormalities in experimental animals. Moreover, we were able to distinguish diffusion abnormalities related to altered intra-cortical tangential fibers from those associated with radial cortical fibers. Histological examinations revealed myelo-architectural abnormalities that explain the alterations observed through dMRI. The methods for dMRI acquisition and analysis used here are available in clinical settings and our work shows their clinical relevance to detect subtle cortical dysplasias through analysis of their microstructural properties.
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Affiliation(s)
- Paulina J. Villaseñor
- Instituto de Neurobiología, Universidad Nacional Autónoma de México Campus Juriquilla, Querétaro, Mexico
| | - David Cortés-Servín
- Instituto de Neurobiología, Universidad Nacional Autónoma de México Campus Juriquilla, Querétaro, Mexico
| | | | - Ana Aquiles
- Instituto de Neurobiología, Universidad Nacional Autónoma de México Campus Juriquilla, Querétaro, Mexico
| | - Hiram Luna-Munguía
- Instituto de Neurobiología, Universidad Nacional Autónoma de México Campus Juriquilla, Querétaro, Mexico
| | | | - Ricardo Coronado-Leija
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States
| | - Jorge Larriva-Sahd
- Instituto de Neurobiología, Universidad Nacional Autónoma de México Campus Juriquilla, Querétaro, Mexico
| | - Luis Concha
- Instituto de Neurobiología, Universidad Nacional Autónoma de México Campus Juriquilla, Querétaro, Mexico
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Pennacchio P, Noé F, Gnatkovsky V, Moroni RF, Zucca I, Regondi MC, Inverardi F, de Curtis M, Frassoni C. Increased pCREB expression and the spontaneous epileptiform activity in a BCNU-treated rat model of cortical dysplasia. Epilepsia 2015; 56:1343-54. [DOI: 10.1111/epi.13070] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Paolo Pennacchio
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Francesco Noé
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Vadym Gnatkovsky
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Ramona Frida Moroni
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Ileana Zucca
- Scientific Department; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Maria Cristina Regondi
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Francesca Inverardi
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Marco de Curtis
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Carolina Frassoni
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
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González-González MA, Ostos-Valverde A, Becerra-Hernández A, Sánchez-Castillo H, Martínez-Torres A. The effect of carmustine on Bergmann cells of the cerebellum. Neurosci Lett 2015; 595:18-24. [PMID: 25841791 DOI: 10.1016/j.neulet.2015.03.068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/21/2015] [Accepted: 03/31/2015] [Indexed: 11/15/2022]
Abstract
Administration of the alkylating agent carmustine to pregnant mice induces hyperlocomotion in the offspring. Motor performance was evaluated by the rotarod task, which revealed that these animals have diminished Grab Frequency and a higher Performance Index, whereas Error of Latency and Latency to Fall were unaffected. Considering the recently revealed role of Bergmann cells of cerebellum in the control of motor activity, we used the transgenic mice GFAP-GFP to explore the impact of carmustine on the organization of these glial cells. Multiple examples of cell layer disorganization were detected; many soma of Bergmann cells were displaced to the external cell layer, and their processes were not well defined until young adulthood. In addition, the roof of the fourth ventricle was convoluted. These observations suggest that the exacerbated locomotion induced by carmustine may be due, in part, to the altered organization of the cell layers of cerebellum.
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Affiliation(s)
- María Alejandra González-González
- Departamento de Neurobiología Celular y Molecular, Laboratorio de Neurobiología Molecular y Celular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, 76230 Querétaro, Qro, Mexico
| | - Aline Ostos-Valverde
- Laboratory of Neuropsychopharmacology and Timing, School of Psychology, UNAM, Building B, B001, Mexico City 04510, Mexico
| | - Armando Becerra-Hernández
- Departamento de Neurobiología Celular y Molecular, Laboratorio de Neurobiología Molecular y Celular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, 76230 Querétaro, Qro, Mexico
| | - Hugo Sánchez-Castillo
- Laboratory of Neuropsychopharmacology and Timing, School of Psychology, UNAM, Building B, B001, Mexico City 04510, Mexico
| | - Ataúlfo Martínez-Torres
- Departamento de Neurobiología Celular y Molecular, Laboratorio de Neurobiología Molecular y Celular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, 76230 Querétaro, Qro, Mexico.
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Figini M, Zucca I, Aquino D, Pennacchio P, Nava S, Di Marzio A, Preti MG, Baselli G, Spreafico R, Frassoni C. In vivo DTI tractography of the rat brain: an atlas of the main tracts in Paxinos space with histological comparison. Magn Reson Imaging 2014; 33:296-303. [PMID: 25482578 DOI: 10.1016/j.mri.2014.11.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 11/20/2014] [Accepted: 11/25/2014] [Indexed: 12/30/2022]
Abstract
Diffusion tensor imaging (DTI) is a magnetic resonance modality that permits to characterize the orientation and integrity of white matter (WM). DTI-based tractography techniques, allowing the virtual reconstruction of WM tract pathways, have found wide application in preclinical neurological research. Recently, anatomically detailed rat brain atlases including DTI data were constructed from ex vivo DTI images, but tractographic atlases of normal rats in vivo are still lacking. We propose here a probabilistic tractographic atlas of the main WM tracts in the healthy rat brain based on in vivo DTI acquisition. Our study was carried out on 10 adult female Sprague-Dawley rats using a 7T preclinical scanner. The MRI protocol permitted a reliable reconstruction of the main rat brain bundles: corpus callosum, cingulum, external capsule, internal capsule, anterior commissure, optic tract. The reconstructed fibers were compared with histological data, proving the viability of in vivo DTI tractography in the rat brain with the proposed acquisition and processing protocol. All the data were registered to a rat brain template in the coordinate system of the commonly used atlas by Paxinos and Watson; then the individual tracts were binarized and averaged, obtaining a probabilistic atlas in Paxinos-Watson space of the main rat brain WM bundles. With respect to the recent high-resolution MRI atlases, the resulting tractographic atlas, available online, provides complementary information about the average anatomical position of the considered WM tracts and their variability between normal animals. Furthermore, reference values for the main DTI-derived parameters, mean diffusivity and fractional anisotropy, were provided. Both these results can be used as references in preclinical studies on pathological rat models involving potential alterations of WM.
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Affiliation(s)
- Matteo Figini
- Scientific Direction, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy; Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Italy
| | - Ileana Zucca
- Scientific Direction, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy.
| | - Domenico Aquino
- Neuroradiology Department, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy
| | - Paolo Pennacchio
- Clinical Epileptology and Experimental Neurophysiology Unit, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy
| | - Simone Nava
- Neuroradiology Department, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy
| | - Alessandro Di Marzio
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Italy
| | - Maria Giulia Preti
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Italy; IRCCS S. Maria Nascente, Fondazione Don Carlo Gnocchi ONLUS, Milano, Italy
| | - Guseppe Baselli
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Italy
| | - Roberto Spreafico
- Clinical Epileptology and Experimental Neurophysiology Unit, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy
| | - Carolina Frassoni
- Clinical Epileptology and Experimental Neurophysiology Unit, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy
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Inverardi F, Chikhladze M, Donzelli A, Moroni RF, Regondi MC, Pennacchio P, Zucca I, Corradini I, Braida D, Sala M, Franceschetti S, Frassoni C. Cytoarchitectural, behavioural and neurophysiological dysfunctions in the BCNU-treated rat model of cortical dysplasia. Eur J Neurosci 2012; 37:150-62. [PMID: 23095101 DOI: 10.1111/ejn.12032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 09/21/2012] [Accepted: 09/21/2012] [Indexed: 11/27/2022]
Abstract
Cortical dysplasias (CDs) include a spectrum of cerebral lesions resulting from cortical development abnormalities during embryogenesis that lead to cognitive disabilities and epilepsy. The experimental model of CD obtained by means of in utero administration of BCNU (1-3-bis-chloroethyl-nitrosurea) to pregnant rats on embryonic day 15 mimics the histopathological abnormalities observed in many patients. The aim of this study was to investigate the behavioural, electrophysiological and anatomical profile of BCNU-treated rats in order to determine whether cortical and hippocampal lesions can directly lead to cognitive dysfunction. The BCNU-treated rats showed impaired short-term working memory but intact long-term aversive memory, whereas their spontaneous motor activity and anxiety-like response were normal. The histopathological and immunohistochemical analyses, made after behavioural tests, revealed the disrupted integrity of neuronal populations and connecting fibres in hippocampus and prefrontal and entorhinal cortices, which are involved in memory processes. An electrophysiological evaluation of the CA1 region of in vitro hippocampal slices indicated a decrease in the efficiency of excitatory synaptic transmission and impaired paired pulse facilitation, but enhanced long-term potentiation (LTP) associated with hyperexcitability in BCNU-treated rats compared with controls. The enhanced LTP, associated with hyperexcitability, may indicate a pathological distortion of long-term plasticity. These findings suggest that prenatal developmental insults at the time of peak cortical neurogenesis can induce anatomical abnormalities associated with severe impairment of spatial working memory in adult BCNU-treated rats and may help to clarify the pathophysiological mechanisms of cognitive dysfunction that is often associated with epilepsy in patients with CD.
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Affiliation(s)
- Francesca Inverardi
- Clinical Epileptology and Experimental Neurophysiology Unit, Fondazione IRCCS Istituto Neurologico C. Besta, Milano, Italy
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