1
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Rocha R, Conceição C, Gonçalves L, Carvalho AC, Maia A, Martins A, Carujo A, Maio A, Forra C, Melita C, Couto D, Fernandes D, Pereira D, Leal E, Sarmento H, Sousa I, Gonçalves JP, Marinho J, Vasconcelos J, Cunha J, Rodrigues J, Silva JM, Caley L, Malheiro L, Santos L, Garcia M, Cunha M, Lima M, Andrade MM, Marques M, Alpalhão M, Silva M, Ferraz R, Soares R, Fernandes S, Llobet S, Cruz S, Guimarães T, Branco T, Robalo-Nunes T, Almeida V, Maia C. Epidemiological and Clinical Aspects of Cutaneous and Mucosal Leishmaniases in Portugal: Retrospective Analysis of Cases Diagnosed in Public Hospitals and Reported in the Literature between 2010 and 2020. Microorganisms 2024; 12:819. [PMID: 38674763 PMCID: PMC11052487 DOI: 10.3390/microorganisms12040819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/14/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
Leishmania infantum, a zoonotic vector-born parasite, is endemic in the Mediterranean region, presenting mostly as visceral (VL), but also as cutaneous (CL) and mucosal leishmaniasis (ML). This study aimed to describe the epidemiological and clinical aspects of the CL and ML cases diagnosed in mainland Portugal between 2010 and 2020. Collaboration was requested from every hospital of the Portuguese National Health System. Cases were screened through a search of diagnostic discharge codes or positive laboratory results for Leishmania infection. Simultaneously, a comprehensive literature search was performed. Descriptive statistics and hypothesis testing were performed using IBM® SPSS® Statistics. A total of 43 CL and 7 ML cases were identified, with a predominance of autochthonous cases (86%). In CL, immunosuppressed individuals constituted a significant proportion of patients (48%), and in this group, disseminated CL (22%) and simultaneous VL (54%) were common. In autochthonous cases, lesions, mostly papules/nodules (62%), were frequently observed on the head (48%). The approach to treatment was very heterogeneous. ML cases were all autochthonous, were diagnosed primarily in older immunosuppressed individuals, and were generally treated with liposomal amphotericin B. The findings suggest a need for enhanced surveillance and reporting, clinical awareness, and diagnostic capacity of these forms of leishmaniasis to mitigate underdiagnosis and improve patient outcomes. A holistic One Health approach is advocated to address the multifaceted challenges posed by leishmaniases in Portugal and beyond.
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Affiliation(s)
- Rafael Rocha
- Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Rua da Junqueira N°100, 1349-008 Lisboa, Portugal; (R.R.); (C.C.)
- Global Health and Tropical Medicine (GHTM), Associate Laboratory in Translation and Innovation Towards Global Health (LA-REAL), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Rua da Junqueira N°100, 1349-008 Lisboa, Portugal
- Centro Hospitalar Universitário de São João, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
| | - Cláudia Conceição
- Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Rua da Junqueira N°100, 1349-008 Lisboa, Portugal; (R.R.); (C.C.)
- Global Health and Tropical Medicine (GHTM), Associate Laboratory in Translation and Innovation Towards Global Health (LA-REAL), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Rua da Junqueira N°100, 1349-008 Lisboa, Portugal
| | - Luzia Gonçalves
- Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Rua da Junqueira N°100, 1349-008 Lisboa, Portugal; (R.R.); (C.C.)
- Global Health and Tropical Medicine (GHTM), Associate Laboratory in Translation and Innovation Towards Global Health (LA-REAL), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Rua da Junqueira N°100, 1349-008 Lisboa, Portugal
- Centro de Estatística e Aplicações da Universidade de Lisboa, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
- Z-Stat4life, Espaço Cowork Baldaya, Palácio Baldaya, Estrada de Benfica N° 701ª, 1549-011 Lisboa, Portugal
| | | | - André Maia
- Centro Hospitalar de Trás-os-Montes e Alto Douro, Avenida da Noruega, 5000-508 Vila Real, Portugal
| | - André Martins
- Hospital da Senhora da Oliveira Guimarães, Rua dos Cutileiros, Creixomil, 4835-044 Guimarães, Portugal
| | - António Carujo
- Centro Hospitalar Universitário de Santo António, Rua Prof. Vicente José de Carvalho N° 37, 4050-366 Porto, Portugal
| | - António Maio
- Centro Hospitalar do Baixo Vouga, Av. Artur Ravara, 3810-501 Aveiro, Portugal
| | - Catarina Forra
- Unidade Local de Saúde de Castelo Branco, Avenida Pedro Álvares Cabral, 6000-085 Castelo Branco, Portugal
| | - Catarina Melita
- Hospital Professor Doutor Fernando Fonseca, IC 19, 2720-276 Amadora, Portugal
| | - Daniela Couto
- Centro Hospitalar Universitário Cova da Beira, Alameda Pêro da Covilhã, 6200-251 Covilhã, Portugal
| | - Diana Fernandes
- Centro Hospitalar de Leiria, Rua das Olhalvas, 2410-197 Leiria, Portugal
| | - Dulce Pereira
- Centro Hospitalar Tondela-Viseu, Avenida Rei D. Duarte, 3504-509 Viseu, Portugal
| | - Ema Leal
- Centro Hospitalar Universitário de Lisboa Central, Rua José António Serrano, 1150-199 Lisboa, Portugal
| | - Helena Sarmento
- Hospital da Senhora da Oliveira Guimarães, Rua dos Cutileiros, Creixomil, 4835-044 Guimarães, Portugal
| | - Inês Sousa
- Centro Hospitalar Universitário Lisboa Norte, Avenida Professor Egas Moniz, 1649-035 Lisboa, Portugal
| | - Jean-Pierre Gonçalves
- Instituto Português de Oncologia de Lisboa Francisco Gentil, Rua Professor Lima Basto, 1099-023 Lisboa, Portugal
| | - Joana Marinho
- Centro Hospitalar Universitário de Coimbra, Praceta Professor Mota Pinto, 3004-561 Coimbra, Portugal
| | - Joana Vasconcelos
- Centro Hospitalar de Lisboa Ocidental, Rua da Junqueira N° 126, 1349-019 Lisboa, Portugal;
| | - João Cunha
- Hospital Distrital de Santarém, Avenida Bernardo Santareno, 2005-177 Santarém, Portugal
| | - João Rodrigues
- Unidade Local de Saúde da Guarda, Avenida Rainha Dona Amélia, 6300-858 Guarda, Portugal
| | - José Miguel Silva
- Unidade Local de Saúde do Norte Alentejano, Avenida de Santo António, Apartado 234, 7301-853 Portalegre, Portugal
| | - Lídia Caley
- Centro Hospitalar do Médio Tejo, Avenida Maria de Lourdes de Mello Castro, Ap. 118, 2304-909 Tomar, Portugal
| | - Luís Malheiro
- Centro Hospitalar de Vila Nova de Gaia/Espinho, Rua Conceição Fernandes, 4434-502 Vila Nova de Gaia, Portugal
| | - Luís Santos
- Centro Hospitalar Universitário de Lisboa Central, Rua José António Serrano, 1150-199 Lisboa, Portugal
| | - Margarida Garcia
- Centro Hospitalar Universitário de Lisboa Central, Rua José António Serrano, 1150-199 Lisboa, Portugal
| | - Maria Cunha
- Centro Hospitalar Universitário Lisboa Norte, Avenida Professor Egas Moniz, 1649-035 Lisboa, Portugal
- Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028 Lisboa, Portugal
| | - Maria Lima
- Centro Hospitalar de Setúbal, Rua Camilo Castelo Branco, Apartado 140, 2910-446 Setúbal, Portugal
| | - Maria Margarida Andrade
- Hospital de Cascais Dr. José de Almeida, Avenida Brigadeiro Victor Novais Gonçalves, 2755-009 Alcabideche, Portugal
| | - Marta Marques
- Centro Hospitalar Tondela-Viseu, Avenida Rei D. Duarte, 3504-509 Viseu, Portugal
| | - Miguel Alpalhão
- Centro Hospitalar Universitário Lisboa Norte, Avenida Professor Egas Moniz, 1649-035 Lisboa, Portugal
| | - Mónica Silva
- Centro Hospitalar Barreiro Montijo, Avenida Movimento das Forças Armadas, 2834-003 Barreiro, Portugal
| | - Rita Ferraz
- Centro Hospitalar do Tâmega e Sousa, Avenida do Hospital Padre Américo, N° 210, Guilhufe, 4560-136 Penafiel, Portugal;
| | - Rui Soares
- Instituto Português de Oncologia de Coimbra Francisco Gentil, Avenida Bissaya Barreto N° 98, 3000-075 Coimbra, Portugal
| | - Salomão Fernandes
- Hospital Beatriz Ângelo, Avenida Carlos Teixeira, N° 3, 2674-514 Loures, Portugal
| | - Samuel Llobet
- Centro Hospitalar Universitário Lisboa Norte, Avenida Professor Egas Moniz, 1649-035 Lisboa, Portugal
| | - Sofia Cruz
- Hospital de Vila Franca de Xira, Estrada Carlos Lima Costa N°2, 2600-009 Vila Franca de Xira, Portugal
| | - Teresa Guimarães
- Unidade Local de Saúde do Nordeste, Avenida Abade de Baçal, 5301-852 Bragança, Portugal
| | - Tiago Branco
- Centro Hospitalar Universitário do Algarve, Rua Leão Penedo, 8000-386 Faro, Portugal
| | - Tomás Robalo-Nunes
- Hospital Garcia de Orta, Avenida Torrado da Silva, 2805-267 Almada, Portugal
| | - Vasco Almeida
- Centro Hospitalar Universitário de Lisboa Central, Rua José António Serrano, 1150-199 Lisboa, Portugal
| | - Carla Maia
- Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Rua da Junqueira N°100, 1349-008 Lisboa, Portugal; (R.R.); (C.C.)
- Global Health and Tropical Medicine (GHTM), Associate Laboratory in Translation and Innovation Towards Global Health (LA-REAL), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Rua da Junqueira N°100, 1349-008 Lisboa, Portugal
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Branco T, Ávila L, Rodrigues A, Ferreira Á. Cecal Volvulus in an Elderly Woman: A Rare Cause of Bowel Obstruction. Cureus 2024; 16:e53571. [PMID: 38445161 PMCID: PMC10914306 DOI: 10.7759/cureus.53571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2024] [Indexed: 03/07/2024] Open
Abstract
Cecal volvulus is a rare, life-threatening form of bowel obstruction caused by the entanglement of the bowel around the mesenteric axis, compromising blood supply and leading to obstruction and ischemia. The diagnosis is challenging due to its highly variable clinical presentation and differential diagnoses, which may delay timely intervention. This is a case report of an 89-year-old woman who presented with a two-day history of lower right quadrant abdominal pain, nausea, and a temporary loss of consciousness. She also reported a history of chronic constipation. Clinical examination and imaging were suggestive of bowel obstruction, prompting further investigation. Plain radiography and abdominal CT confirmed bowel obstruction, with suspicion of volvulus. The diagnostic uncertainty between cecal and sigmoid volvulus prompted a colonoscopy, which excluded sigmoid volvulus. Emergency laparotomy revealed cecal volvulus and a distended cecum with ischemic changes but without necrosis. A right hemicolectomy was performed, and the patient recovered well postoperatively. This case report aims to expand the medical knowledge around the topic of cecal volvulus. It underscores the challenges in diagnosing and managing this condition and emphasizes the importance of prompt recognition and surgical intervention to improve patient outcomes.
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Affiliation(s)
- Tiago Branco
- General Surgery, Centro Hospitalar do Oeste, Caldas da Rainha, PRT
| | - Leonor Ávila
- General Surgery, Centro Hospitalar Lisboa Ocidental - Hospital Egas Moniz, Lisboa, PRT
| | - Ana Rodrigues
- General Surgery, Centro Hospitalar do Oeste, Caldas da Rainha, PRT
| | - Ágata Ferreira
- General Surgery, Centro Hospitalar do Oeste, Caldas da Rainha, PRT
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3
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Lefler Y, Branco T. How the brain plays musical statues. Nat Neurosci 2023; 26:1482-1484. [PMID: 37550512 DOI: 10.1038/s41593-023-01400-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Affiliation(s)
- Yaara Lefler
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK
| | - Tiago Branco
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK.
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4
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Abreu M, Branco T, Figueiroa S, Reis CF. Parental gonadossomatic mosaicism in HIVEP2-related intellectual disability and impact on genetic counseling-case report. Front Genet 2023; 14:1156847. [PMID: 37441550 PMCID: PMC10333530 DOI: 10.3389/fgene.2023.1156847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 05/19/2023] [Indexed: 07/15/2023] Open
Abstract
Intellectual development disorder, autosomal dominant 43 (MRD43) is an autosomal dominant disorder caused by heterozygous mutations in the HIVEP2 gene. In this report, we describe a case of a 4-year-old boy with global development delay, hypotonia, and dysmorphic features, in whom the finding of a heterozygous nonsense pathogenic variant in exon 5 of HIVEP2 [c.2827C>T p. (Arg943*)] through WES established a MRD43 diagnosis. Our patient's phenotype overlaps with other MRD43 descriptions in the literature. Unlike previously reported cases, where the condition was almost invariably de novo, the healthy mother in this case presented mosaicism for the pathogenic variant. Thus, the recurrence risk increased significantly from 1% to up to 50%. The description of a variant inherited for MDR43 is singular in the literature and this description highlights the importance of parental studies for accurate genetic counseling, particularly for family planning.
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Affiliation(s)
- Maria Abreu
- Medical Genetics Department, Centro de Genética Médica Jacinto de Magalhães, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Tiago Branco
- Pediatric Department, Centro Hospitalar Tâmega e Sousa, Penafiel, Portugal
| | - Sónia Figueiroa
- Division of Pediatric Neurology, Department of Child and Adolescent, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Cláudia Falcão Reis
- Medical Genetics Department, Centro de Genética Médica Jacinto de Magalhães, Centro Hospitalar Universitário do Porto, Porto, Portugal
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s—PT Government Associate Laboratory, Braga/Guimaraes, Portugal
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5
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Shamash P, Lee S, Saxe AM, Branco T. Mice identify subgoal locations through an action-driven mapping process. Neuron 2023; 111:1966-1978.e8. [PMID: 37119818 PMCID: PMC10636595 DOI: 10.1016/j.neuron.2023.03.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 10/12/2022] [Accepted: 03/27/2023] [Indexed: 05/01/2023]
Abstract
Mammals form mental maps of the environments by exploring their surroundings. Here, we investigate which elements of exploration are important for this process. We studied mouse escape behavior, in which mice are known to memorize subgoal locations-obstacle edges-to execute efficient escape routes to shelter. To test the role of exploratory actions, we developed closed-loop neural-stimulation protocols for interrupting various actions while mice explored. We found that blocking running movements directed at obstacle edges prevented subgoal learning; however, blocking several control movements had no effect. Reinforcement learning simulations and analysis of spatial data show that artificial agents can match these results if they have a region-level spatial representation and explore with object-directed movements. We conclude that mice employ an action-driven process for integrating subgoals into a hierarchical cognitive map. These findings broaden our understanding of the cognitive toolkit that mammals use to acquire spatial knowledge.
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Affiliation(s)
- Philip Shamash
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London W1T 4JG, UK
| | - Sebastian Lee
- UCL Gatsby Computational Neuroscience Unit, London W1T 4JG, UK
| | - Andrew M Saxe
- UCL Gatsby Computational Neuroscience Unit, London W1T 4JG, UK
| | - Tiago Branco
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London W1T 4JG, UK.
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6
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Mateus C, Branco M, Neves P, Branco T, Capelas M, Makitie A, Ravasco P, Mateus C, Branco MG, Neves PM, Santos T, Capelas ML, Makitie A, Ravasco P. N-3 Fatty Acids Supplementation And Chemotherapy Induced Toxicity: Scoping Review. Clin Nutr ESPEN 2023. [DOI: 10.1016/j.clnesp.2022.09.348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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Branco T, Barbosa A, Cunha N, Gouveia J, Lopes JM. Brugada Phenocopy Caused by Intracranial Hemorrhage. Cureus 2023; 15:e35687. [PMID: 37012940 PMCID: PMC10066709 DOI: 10.7759/cureus.35687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2023] [Indexed: 03/06/2023] Open
Abstract
Brugada syndrome (BrS) is a congenital channelopathy associated with an increased risk of malignant ventricular arrhythmias and sudden cardiac death in individuals without any structural cardiopathy. Brugada phenocopies (BrPs) are clinical entities that present electrocardiographic patterns similar to those of BrS that are elicited only under transitory pathophysiological conditions, with normalization of the ECG pattern after the resolution of those conditions. We present a rare case of BrP due to intracranial hemorrhage. We also present and discuss the diagnostic criteria for BrPs and their application to this case.
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Paiva Ferreira I, Alba D, Fernandes S, Tuna T, Branco T, Abreu Ferreira J. Torsion of undescended testicle in an adolescent: A rare challenging surgical emergency ☆. Pediatr Neonatol 2023:S1875-9572(23)00037-2. [PMID: 36872196 DOI: 10.1016/j.pedneo.2022.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/15/2022] [Accepted: 12/30/2022] [Indexed: 02/18/2023] Open
Affiliation(s)
- Inês Paiva Ferreira
- Department of Pediatrics, Centro Hospitalar Do Tâmega e Sousa, Penafiel, Portugal.
| | - Diana Alba
- Department of Pediatrics, Centro Hospitalar Do Tâmega e Sousa, Penafiel, Portugal
| | - Sara Fernandes
- Department of Pediatric Surgery, Centro Hospitalar Universitário de São João, Porto, Portugal
| | - Tiago Tuna
- Department of Pediatric Surgery, Centro Hospitalar Universitário de São João, Porto, Portugal
| | - Tiago Branco
- Department of Pediatrics, Centro Hospitalar Do Tâmega e Sousa, Penafiel, Portugal
| | - Jorge Abreu Ferreira
- Department of Pediatrics, Centro Hospitalar Do Tâmega e Sousa, Penafiel, Portugal
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Branco T, Marques C, Santos VC, Lopes JM. Gradenigo's Syndrome With Septic Lateral Sinus Thrombosis. Cureus 2023; 15:e34797. [PMID: 36915831 PMCID: PMC10007907 DOI: 10.7759/cureus.34797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2023] [Indexed: 02/11/2023] Open
Abstract
Gradenigo's syndrome (GS) is a rare but life-threatening complication of acute otitis media (AOM). It is classically defined as a clinical triad of acute otitis media, ipsilateral sixth (abducens) nerve palsy, and pain in the distribution of the first and second branches of the trigeminal nerve. Another rare but serious complication of AOM is venous sinus thrombosis, which is often associated with GS. The diagnosis of these conditions requires clinical suspicion, sound interpretation of signs and symptoms, and the use of the correct imaging techniques. Here, we present the case of an 81-year-old man with a previous history of recurrent otitis media, who presented with GS and septic lateral sinus thrombosis. The clinical presentation, physiopathology, and management of these conditions are discussed.
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Affiliation(s)
- Tiago Branco
- Serviço de Medicina 2, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisboa, PRT
| | | | - Vera C Santos
- Serviço de Medicina Intensiva, Hospital Prof. Doutor Fernando Fonseca, Amadora, PRT
| | - João M Lopes
- Serviço de Medicina 2, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisboa, PRT
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10
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Campagner D, Vale R, Tan YL, Iordanidou P, Pavón Arocas O, Claudi F, Stempel AV, Keshavarzi S, Petersen RS, Margrie TW, Branco T. A cortico-collicular circuit for orienting to shelter during escape. Nature 2023; 613:111-119. [PMID: 36544025 PMCID: PMC7614651 DOI: 10.1038/s41586-022-05553-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 11/10/2022] [Indexed: 12/24/2022]
Abstract
When faced with predatory threats, escape towards shelter is an adaptive action that offers long-term protection against the attacker. Animals rely on knowledge of safe locations in the environment to instinctively execute rapid shelter-directed escape actions1,2. Although previous work has identified neural mechanisms of escape initiation3,4, it is not known how the escape circuit incorporates spatial information to execute rapid flights along the most efficient route to shelter. Here we show that the mouse retrosplenial cortex (RSP) and superior colliculus (SC) form a circuit that encodes the shelter-direction vector and is specifically required for accurately orienting to shelter during escape. Shelter direction is encoded in RSP and SC neurons in egocentric coordinates and SC shelter-direction tuning depends on RSP activity. Inactivation of the RSP-SC pathway disrupts the orientation to shelter and causes escapes away from the optimal shelter-directed route, but does not lead to generic deficits in orientation or spatial navigation. We find that the RSP and SC are monosynaptically connected and form a feedforward lateral inhibition microcircuit that strongly drives the inhibitory collicular network because of higher RSP input convergence and synaptic integration efficiency in inhibitory SC neurons. This results in broad shelter-direction tuning in inhibitory SC neurons and sharply tuned excitatory SC neurons. These findings are recapitulated by a biologically constrained spiking network model in which RSP input to the local SC recurrent ring architecture generates a circular shelter-direction map. We propose that this RSP-SC circuit might be specialized for generating collicular representations of memorized spatial goals that are readily accessible to the motor system during escape, or more broadly, during navigation when the goal must be reached as fast as possible.
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Affiliation(s)
- Dario Campagner
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK
- UCL Gatsby Computational Neuroscience Unit, London, UK
| | - Ruben Vale
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Yu Lin Tan
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK
| | | | - Oriol Pavón Arocas
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK
| | - Federico Claudi
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK
| | - A Vanessa Stempel
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK
| | | | | | - Troy W Margrie
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK
| | - Tiago Branco
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK.
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Barkus C, Bergmann C, Branco T, Carandini M, Chadderton PT, Galiñanes GL, Gilmour G, Huber D, Huxter JR, Khan AG, King AJ, Maravall M, O'Mahony T, Ragan CI, Robinson ESJ, Schaefer AT, Schultz SR, Sengpiel F, Prescott MJ. Refinements to rodent head fixation and fluid/food control for neuroscience. J Neurosci Methods 2022; 381:109705. [PMID: 36096238 DOI: 10.1016/j.jneumeth.2022.109705] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 09/01/2022] [Accepted: 09/03/2022] [Indexed: 12/14/2022]
Abstract
The use of head fixation in mice is increasingly common in research, its use having initially been restricted to the field of sensory neuroscience. Head restraint has often been combined with fluid control, rather than food restriction, to motivate behaviour, but this too is now in use for both restrained and non-restrained animals. Despite this, there is little guidance on how best to employ these techniques to optimise both scientific outcomes and animal welfare. This article summarises current practices and provides recommendations to improve animal wellbeing and data quality, based on a survey of the community, literature reviews, and the expert opinion and practical experience of an international working group convened by the UK's National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs). Topics covered include head fixation surgery and post-operative care, habituation to restraint, and the use of fluid/food control to motivate performance. We also discuss some recent developments that may offer alternative ways to collect data from large numbers of behavioural trials without the need for restraint. The aim is to provide support for researchers at all levels, animal care staff, and ethics committees to refine procedures and practices in line with the refinement principle of the 3Rs.
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Affiliation(s)
- Chris Barkus
- National Centre for Replacement, Refinement and Reduction of Animals in Research (NC3Rs), London, UK.
| | | | - Tiago Branco
- Sainsbury Wellcome Centre, University College London, London, UK
| | - Matteo Carandini
- Institute of Ophthalmology, University College London, London, UK
| | - Paul T Chadderton
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | | | | | - Daniel Huber
- Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland
| | | | - Adil G Khan
- Centre for Developmental Neurobiology, King's College London, London, UK
| | - Andrew J King
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Miguel Maravall
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, UK
| | - Tina O'Mahony
- Sainsbury Wellcome Centre, University College London, London, UK
| | - C Ian Ragan
- National Centre for Replacement, Refinement and Reduction of Animals in Research (NC3Rs), London, UK
| | - Emma S J Robinson
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Andreas T Schaefer
- Sensory Circuits and Neurotechnology Laboratory, The Francis Crick Institute, London, UK; Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Simon R Schultz
- Centre for Neurotechnology and Department of Bioengineering, Imperial College London, London, UK
| | | | - Mark J Prescott
- National Centre for Replacement, Refinement and Reduction of Animals in Research (NC3Rs), London, UK
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12
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Cardoso I, Branco T, Constante A, Viegas J, Grazina A, Teixeira B, Jacinto S, Castelo A, Rito T, Martins D, Ferreira R, Sousa L. Impact of coronavirus disease 2019 on adult patients with congenital heart disease. Eur Heart J 2022. [PMCID: PMC9619529 DOI: 10.1093/eurheartj/ehac544.1858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background COVID-19 is responsible for a worldwide pandemic, causing more than 18,000 deaths to date in Portugal. Data already exists regarding the increased risk of adverse events in patients with cardiovascular diseases, however the impact of SARS-CoV-2 infection in patients (P) with congenital heart disease (CHD) is still under investigation. Purpose To study the impact of COVID-19 in a adult patients with CHD Methods Adult patients seen at the CHD outpatient's clinic at a tertiary centre, who became infected with SARS-CoV-2 infection up to December 2021 were included. Assessment of patients' symptoms, need for hospitalization and admission in an intensive care unit was assessed based on medical records. Results We identified seventy-nine patients (pts) with COVID-19 infection. Symptoms were present in 67 (84%). The median age was 44 (15) years, 52% were females. Eight P (10%) had complex cyanotic disease; seven Tetralogy of Fallot; five (6%) transposition of great arteries; eight (10%) right ventricle obstacle; two (3%) atrioventricular canal defect; sixteen (20%) atrial septal defect; nine (11%) ventricular septal defect; eight (10%) aortic coarctation; two (3%) had Eisenmenger syndrome. 49% of P had previous surgery or percutaneous procedure. 63% of P were at New York Heart Association (NYHA) class of I and 30% at NYHA II. Mild symptoms were reported by 56 P (71%). Ten adults (7,9%) experienced moderate symptoms (dyspnea and hypoxia) that led to hospitalization for oxygen therapy, none required mechanical ventilation. One death was reported in an 83-year-old patient with non-corrected interventricular communication and compromised biventricular function. There was a significant association between the gravity of CHD and hospitalizations (p=0.02). Conclusion Our pts had mainly mild to moderate symptoms and did not appear to have a disproportionately negative outcome; the need for hospitalization was more frequent in patients with higher CHD gravity. These findings are in line with the emerging data regarding COVID-19 in CHD P, and may be in part explained by the patient's young age and functional status. Funding Acknowledgement Type of funding sources: None.
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Affiliation(s)
- I Cardoso
- Hospital de Santa Marta , Lisbon , Portugal
| | - T Branco
- Hospital de Santa Marta , Lisbon , Portugal
| | | | - J Viegas
- Hospital de Santa Marta , Lisbon , Portugal
| | - A Grazina
- Hospital de Santa Marta , Lisbon , Portugal
| | - B Teixeira
- Hospital de Santa Marta , Lisbon , Portugal
| | - S Jacinto
- Hospital de Santa Marta , Lisbon , Portugal
| | - A Castelo
- Hospital de Santa Marta , Lisbon , Portugal
| | - T Rito
- Hospital de Santa Marta , Lisbon , Portugal
| | - D Martins
- Hospital de Santa Marta , Lisbon , Portugal
| | - R Ferreira
- Hospital de Santa Marta , Lisbon , Portugal
| | - L Sousa
- Hospital de Santa Marta , Lisbon , Portugal
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13
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Pavón Arocas O, Branco T. Preparation of acute midbrain slices containing the superior colliculus and periaqueductal Gray for patch-clamp recordings. PLoS One 2022; 17:e0271832. [PMID: 35951507 PMCID: PMC9371254 DOI: 10.1371/journal.pone.0271832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 07/07/2022] [Indexed: 11/18/2022] Open
Abstract
This protocol is a practical guide for preparing acute coronal slices from the midbrain of young adult mice for electrophysiology experiments. It describes two different sets of solutions with their respective incubation strategies and two alternative procedures for brain extraction: decapitation under terminal isoflurane anaesthesia and intracardial perfusion with artificial cerebrospinal fluid under terminal isoflurane anaesthesia. Slices can be prepared from wild-type mice as well as from mice that have been genetically modified or transfected with viral constructs to label subsets of cells. The preparation can be used to investigate the electrophysiological properties of midbrain neurons in combination with pharmacology, opto- and chemogenetic manipulations, and calcium imaging; which can be followed by morphological reconstruction, immunohistochemistry, or single-cell transcriptomics. The protocol also provides a detailed list of materials and reagents including the design for a low-cost and easy to assemble 3D printed slice recovery chamber, general advice for troubleshooting common issues leading to suboptimal slice quality, and some suggestions to ensure good maintenance of a patch-clamp rig.
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Affiliation(s)
- Oriol Pavón Arocas
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, United Kingdom
- * E-mail:
| | - Tiago Branco
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, United Kingdom
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14
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Claudi F, Branco T. Differential Geometry Methods for Constructing Manifold-Targeted Recurrent Neural Networks. Neural Comput 2022; 34:1790-1811. [PMID: 35798324 DOI: 10.1162/neco_a_01511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 03/03/2022] [Indexed: 11/04/2022]
Abstract
Neural computations can be framed as dynamical processes, whereby the structure of the dynamics within a neural network is a direct reflection of the computations that the network performs. A key step in generating mechanistic interpretations within this computation through dynamics framework is to establish the link among network connectivity, dynamics, and computation. This link is only partly understood. Recent work has focused on producing algorithms for engineering artificial recurrent neural networks (RNN) with dynamics targeted to a specific goal manifold. Some of these algorithms require only a set of vectors tangent to the target manifold to be computed and thus provide a general method that can be applied to a diverse set of problems. Nevertheless, computing such vectors for an arbitrary manifold in a high-dimensional state space remains highly challenging, which in practice limits the applicability of this approach. Here we demonstrate how topology and differential geometry can be leveraged to simplify this task by first computing tangent vectors on a low-dimensional topological manifold and then embedding these in state space. The simplicity of this procedure greatly facilitates the creation of manifold-targeted RNNs, as well as the process of designing task-solving, on-manifold dynamics. This new method should enable the application of network engineering-based approaches to a wide set of problems in neuroscience and machine learning. Our description of how fundamental concepts from differential geometry can be mapped onto different aspects of neural dynamics is a further demonstration of how the language of differential geometry can enrich the conceptual framework for describing neural dynamics and computation.
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Affiliation(s)
- Federico Claudi
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London W1T 4JG, U.K.
| | - Tiago Branco
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London W1T 4JG, U.K.
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15
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Shamash P, Branco T. Protocol to Study Spatial Subgoal Learning Using Escape Behavior in Mice. Bio Protoc 2022; 12:e4443. [PMID: 35864903 PMCID: PMC9257842 DOI: 10.21769/bioprotoc.4443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 05/05/2022] [Accepted: 05/08/2022] [Indexed: 12/29/2022] Open
Abstract
Rodent spatial navigation is a key model system for studying mammalian cognition and its neural mechanisms. Of particular interest is how animals memorize the structure of their environments and compute multi-step routes to a goal. Previous work on multi-step spatial reasoning has generally involved placing rodents at the start of a maze until they learn to navigate to a reward without making wrong turns. It thus remains poorly understood how animals rapidly learn about the structure of naturalistic open environments with goals and obstacles. Here we present an assay in which mice spontaneously memorize two-step routes in an environment with a shelter and an obstacle. We allow the mice to explore this environment for 20 min, and then we remove the obstacle. We then present auditory threat stimuli, causing the mouse to escape to the shelter. Finally, we record each escape route and measure whether it targets the shelter directly (a 'homing-vector' escape) or instead targets the location where the obstacle edge was formerly located (an 'edge-vector' escape). Since the obstacle is no longer there, these obstacle-edge-directed escape routes provide evidence that the mouse has memorized a subgoal location, i.e., a waypoint targeted in order to efficiently get to the shelter in the presence of an obstacle. By taking advantage of instinctive escape responses, this assay probes a multi-step spatial memory that is learned in a single session without pretraining. The subgoal learning phenomenon it generates can be useful not only for researchers working on navigation and instinctive behavior, but also for neuroscientists studying the neural basis of multi-step spatial reasoning.
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Affiliation(s)
- Philip Shamash
- Sainsbury Wellcome Centre, University College London, London, UK
| | - Tiago Branco
- Sainsbury Wellcome Centre, University College London, London, UK
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16
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Branco T, Murthy M. Editorial overview: Neurobiology of behavior. Curr Opin Neurobiol 2022; 73:102559. [PMID: 35654560 DOI: 10.1016/j.conb.2022.102559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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17
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Lenzi SC, Cossell L, Grainger B, Olesen SF, Branco T, Margrie TW. Threat history controls flexible escape behavior in mice. Curr Biol 2022; 32:2972-2979.e3. [PMID: 35659863 PMCID: PMC9616793 DOI: 10.1016/j.cub.2022.05.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 03/08/2022] [Accepted: 05/10/2022] [Indexed: 11/24/2022]
Abstract
In many instances, external sensory-evoked neuronal activity is used by the brain to select the most appropriate behavioral response. Predator-avoidance behaviors such as freezing and escape1,2 are of particular interest since these stimulus-evoked responses are behavioral manifestations of a decision-making process that is fundamental to survival.3,4 Over the lifespan of an individual, however, the threat value of agents in the environment is believed to undergo constant revision,5 and in some cases, repeated avoidance of certain stimuli may no longer be an optimal behavioral strategy.6 To begin to study this type of adaptive control of decision-making, we devised an experimental paradigm to probe the properties of threat escape in the laboratory mouse Mus musculus. First, we found that while robust escape to visual looming stimuli can be observed after 2 days of social isolation, mice can also rapidly learn that such stimuli are non-threatening. This learned suppression of escape (LSE) is extremely robust and can persist for weeks and is not a generalized adaptation, since flight responses to novel live prey and auditory threat stimuli in the same environmental context were maintained. We also show that LSE cannot be explained by trial number or a simple form of stimulus desensitization since it is dependent on threat-escape history. We propose that the action selection process mediating escape behavior is constantly updated by recent threat history and that LSE can be used as a robust model system to understand the neurophysiological mechanisms underlying experience-dependent decision-making. Individually housed, but not group-housed, mice show robust escape to looming stimuli Mice can learn to suppress escape, and LSE memory is long lasting LSE is not a general adaptation since it is stimulus specific LSE is not simply habituation and is dependent on recent threat-escape experience
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Affiliation(s)
- Stephen C Lenzi
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, 25 Howland Street, London W1T 4JG, UK
| | - Lee Cossell
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, 25 Howland Street, London W1T 4JG, UK
| | - Benjamin Grainger
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, 25 Howland Street, London W1T 4JG, UK
| | - Sarah F Olesen
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, 25 Howland Street, London W1T 4JG, UK
| | - Tiago Branco
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, 25 Howland Street, London W1T 4JG, UK
| | - Troy W Margrie
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, 25 Howland Street, London W1T 4JG, UK.
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18
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Claudi F, Campagner D, Branco T. Innate heuristics and fast learning support escape route selection in mice. Curr Biol 2022; 32:2980-2987.e5. [PMID: 35617953 PMCID: PMC9616796 DOI: 10.1016/j.cub.2022.05.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 03/14/2022] [Accepted: 05/09/2022] [Indexed: 11/26/2022]
Abstract
When faced with imminent danger, animals must rapidly take defensive actions to reach safety. Mice can react to threatening stimuli in ∼250 milliseconds1 and, in simple environments, use spatial memory to quickly escape to shelter.2,3 Natural habitats, however, often offer multiple routes to safety that animals must identify and choose from.4 This is challenging because although rodents can learn to navigate complex mazes,5,6 learning the value of different routes through trial and error during escape could be deadly. Here, we investigated how mice learn to choose between different escape routes. Using environments with paths to shelter of varying length and geometry, we find that mice prefer options that minimize path distance and angle relative to the shelter. This strategy is already present during the first threat encounter and after only ∼10 minutes of exploration in a novel environment, indicating that route selection does not require experience of escaping. Instead, an innate heuristic assigns survival value to each path after rapidly learning the spatial environment. This route selection process is flexible and allows quick adaptation to arenas with dynamic geometries. Computational modeling shows that model-based reinforcement learning agents replicate the observed behavior in environments where the shelter location is rewarding during exploration. These results show that mice combine fast spatial learning with innate heuristics to choose escape routes with the highest survival value. The results further suggest that integrating prior knowledge acquired through evolution with knowledge learned from experience supports adaptation to changing environments and minimizes the need for trial and error when the errors are costly. Mice learn to escape via the fastest route after ∼10 minutes in a new environment Escape routes are learned during exploration and do not require threat exposure Mice prefer escape routes that minimize path distance and angle to shelter Fast route learning can be replicated by model-based reinforcement learning agents
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Affiliation(s)
- Federico Claudi
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London W1T 4JG, UK
| | - Dario Campagner
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London W1T 4JG, UK; Gatsby Unit, UCL, London W1T 4JG, UK
| | - Tiago Branco
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London W1T 4JG, UK.
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19
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Tyson AL, Vélez-Fort M, Rousseau CV, Cossell L, Tsitoura C, Lenzi SC, Obenhaus HA, Claudi F, Branco T, Margrie TW. Accurate determination of marker location within whole-brain microscopy images. Sci Rep 2022; 12:867. [PMID: 35042882 PMCID: PMC8766598 DOI: 10.1038/s41598-021-04676-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 12/22/2021] [Indexed: 11/25/2022] Open
Abstract
High-resolution whole-brain microscopy provides a means for post hoc determination of the location of implanted devices and labelled cell populations that are necessary to interpret in vivo experiments designed to understand brain function. Here we have developed two plugins (brainreg and brainreg-segment) for the Python-based image viewer napari, to accurately map any object in a common coordinate space. We analysed the position of dye-labelled electrode tracks and two-photon imaged cell populations expressing fluorescent proteins. The precise location of probes and cells were physiologically interrogated and revealed accurate segmentation with near-cellular resolution.
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Affiliation(s)
- Adam L Tyson
- Sainsbury Wellcome Centre, University College London, London, UK
| | - Mateo Vélez-Fort
- Sainsbury Wellcome Centre, University College London, London, UK
| | - Charly V Rousseau
- Sainsbury Wellcome Centre, University College London, London, UK
- Inserm, CNRS, Institut du Cerveau - Paris Brain Institute - ICM, Sorbonne Université, Paris, France
| | - Lee Cossell
- Sainsbury Wellcome Centre, University College London, London, UK
| | | | - Stephen C Lenzi
- Sainsbury Wellcome Centre, University College London, London, UK
| | - Horst A Obenhaus
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Trondheim, Norway
| | - Federico Claudi
- Sainsbury Wellcome Centre, University College London, London, UK
| | - Tiago Branco
- Sainsbury Wellcome Centre, University College London, London, UK
| | - Troy W Margrie
- Sainsbury Wellcome Centre, University College London, London, UK.
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20
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Fratzl A, Koltchev AM, Vissers N, Tan YL, Marques-Smith A, Stempel AV, Branco T, Hofer SB. Flexible inhibitory control of visually evoked defensive behavior by the ventral lateral geniculate nucleus. Neuron 2021; 109:3810-3822.e9. [PMID: 34614420 PMCID: PMC8648186 DOI: 10.1016/j.neuron.2021.09.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/22/2021] [Accepted: 09/01/2021] [Indexed: 01/23/2023]
Abstract
Animals can choose to act upon, or to ignore, sensory stimuli, depending on circumstance and prior knowledge. This flexibility is thought to depend on neural inhibition, through suppression of inappropriate and disinhibition of appropriate actions. Here, we identified the ventral lateral geniculate nucleus (vLGN), an inhibitory prethalamic area, as a critical node for control of visually evoked defensive responses in mice. The activity of vLGN projections to the medial superior colliculus (mSC) is modulated by previous experience of threatening stimuli, tracks the perceived threat level in the environment, and is low prior to escape from a visual threat. Optogenetic stimulation of the vLGN abolishes escape responses, and suppressing its activity lowers the threshold for escape and increases risk-avoidance behavior. The vLGN most strongly affects visual threat responses, potentially via modality-specific inhibition of mSC circuits. Thus, inhibitory vLGN circuits control defensive behavior, depending on an animal’s prior experience and its anticipation of danger in the environment. Activity of vLGN axons in the mSC reflects the previous experience of threat The vLGN bidirectionally controls escape from visual threat Activating the vLGN specifically reduces the activity of visual units in mSC Activating vLGN axons in the mSC specifically suppresses escape from visual threat
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Affiliation(s)
- Alex Fratzl
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - Alice M Koltchev
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - Nicole Vissers
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - Yu Lin Tan
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - Andre Marques-Smith
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - A Vanessa Stempel
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - Tiago Branco
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - Sonja B Hofer
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK.
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21
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Keshavarzi S, Bracey EF, Faville RA, Campagner D, Tyson AL, Lenzi SC, Branco T, Margrie TW. Multisensory coding of angular head velocity in the retrosplenial cortex. Neuron 2021; 110:532-543.e9. [PMID: 34788632 PMCID: PMC8823706 DOI: 10.1016/j.neuron.2021.10.031] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 07/29/2021] [Accepted: 10/20/2021] [Indexed: 01/05/2023]
Abstract
To successfully navigate the environment, animals depend on their ability to continuously track their heading direction and speed. Neurons that encode angular head velocity (AHV) are fundamental to this process, yet the contribution of various motion signals to AHV coding in the cortex remains elusive. By performing chronic single-unit recordings in the retrosplenial cortex (RSP) of the mouse and tracking the activity of individual AHV cells between freely moving and head-restrained conditions, we find that vestibular inputs dominate AHV signaling. Moreover, the addition of visual inputs onto these neurons increases the gain and signal-to-noise ratio of their tuning during active exploration. Psychophysical experiments and neural decoding further reveal that vestibular-visual integration increases the perceptual accuracy of angular self-motion and the fidelity of its representation by RSP ensembles. We conclude that while cortical AHV coding requires vestibular input, where possible, it also uses vision to optimize heading estimation during navigation. Angular head velocity (AHV) coding is widespread in the retrosplenial cortex (RSP) AHV cells maintain their tuning during passive motion and require vestibular input The perception of angular self-motion is improved when visual cues are present AHV coding is similarly improved when both vestibular and visual stimuli are used
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Affiliation(s)
- Sepiedeh Keshavarzi
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London (UCL), 25 Howland Street, London W1T 4JG, United Kingdom.
| | - Edward F Bracey
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London (UCL), 25 Howland Street, London W1T 4JG, United Kingdom
| | - Richard A Faville
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London (UCL), 25 Howland Street, London W1T 4JG, United Kingdom
| | - Dario Campagner
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London (UCL), 25 Howland Street, London W1T 4JG, United Kingdom; Gatsby Computational Neuroscience Unit, University College London (UCL), 25 Howland Street, London W1T 4JG, United Kingdom
| | - Adam L Tyson
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London (UCL), 25 Howland Street, London W1T 4JG, United Kingdom
| | - Stephen C Lenzi
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London (UCL), 25 Howland Street, London W1T 4JG, United Kingdom
| | - Tiago Branco
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London (UCL), 25 Howland Street, London W1T 4JG, United Kingdom
| | - Troy W Margrie
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London (UCL), 25 Howland Street, London W1T 4JG, United Kingdom.
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22
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Maximiano C, Silva A, Duro I, Branco T, Correia-Costa L, Teixeira A, Rocha L, Costa T, Matos P, Faria MDS, Mota C, Afonso AC. Genetic atypical hemolytic uremic syndrome in children: a 20-year experience from a tertiary center. ACTA ACUST UNITED AC 2021; 43:311-317. [PMID: 33988670 PMCID: PMC8428634 DOI: 10.1590/2175-8239-jbn-2020-0199] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 02/23/2021] [Indexed: 11/22/2022]
Abstract
Introduction: Atypical hemolytic uremic syndrome (aHUS) is a rare disorder characterized by
the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute
kidney injury, which primarily affects preschool-aged children. This study’s
aim was to describe the clinical profile, management, and long-term outcome
of the genetic aHUS patients admitted to a tertiary care pediatric
nephrology center during 20 years. Methods: We performed a retrospective analysis of the clinical records of all aHUS
patients younger than 18 years with identified genetic mutations. Data on
clinical features, genetic study, therapeutic interventions, and long-term
outcomes were reviewed. Results: Five cases of aHUS with an identified genetic mutation were included; all
were inaugural cases with the youngest being 4 months old. Complement factor
H gene mutation was identified in four patients. Therapeutic plasma exchange
was performed for acute management in 4 patients, one of whom also needed
acute renal replacement therapy (peritoneal dialysis). All patients went on
complete remission, 2 had more than one relapse but only 1 of these
progressed to chronic kidney disease during the follow-up period (median
(25th-75th percentile), 136 (43.5-200.5) months). Conclusion: In children, the prognosis of renal function seems to be strongly dependent
on the genetic background, thus being crucial to perform genetic study in
all aHUS cases. In our cohort, 2 patients presented genetic mutations not
previously described. Recent innovations on the genetic field leading to the
identification of new mutations has lead to a better understanding of aHUS
pathogenesis, but further studies, focusing on the genotype-phenotype
correlation, with longer follow-up periods, are needed.
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Affiliation(s)
| | - Andreia Silva
- Centro Hospitalar Tondela-Viseu, Departamento de Nefrologia, Viseu, Portugal
| | - Inês Duro
- Centro Hospitalar Universitário do Porto, Centro Materno-Infantil do Norte, Departamento de Pediatria, Porto, Portugal
| | - Tiago Branco
- Centro Hospitalar do Tâmega e Sousa, Departamento de Pediatria, Penafiel, Portugal
| | - Liane Correia-Costa
- Centro Hospitalar Universitário do Porto, Centro Materno-Infantil do Norte, Unidade de Nefrologia Pediátrica, Porto, Portugal.,Universidade do Porto, Instituto de Ciências Biomédicas Abel Salazar, Porto, Portugal.,Universidade do Porto, Instituto de Saúde Pública, Porto, Portugal
| | - Ana Teixeira
- Centro Hospitalar Universitário do Porto, Centro Materno-Infantil do Norte, Unidade de Nefrologia Pediátrica, Porto, Portugal
| | - Liliana Rocha
- Centro Hospitalar Universitário do Porto, Centro Materno-Infantil do Norte, Unidade de Nefrologia Pediátrica, Porto, Portugal
| | - Teresa Costa
- Centro Hospitalar Universitário do Porto, Centro Materno-Infantil do Norte, Unidade de Nefrologia Pediátrica, Porto, Portugal
| | - Paula Matos
- Centro Hospitalar Universitário do Porto, Centro Materno-Infantil do Norte, Unidade de Nefrologia Pediátrica, Porto, Portugal
| | - Maria do Sameiro Faria
- Centro Hospitalar Universitário do Porto, Centro Materno-Infantil do Norte, Unidade de Nefrologia Pediátrica, Porto, Portugal.,Universidade Nova de Lisboa, REQUIMTE, Unidade de Investigação em Biociências Moleculares Aplicadas, Porto, Portugal
| | - Conceição Mota
- Centro Hospitalar Universitário do Porto, Centro Materno-Infantil do Norte, Unidade de Nefrologia Pediátrica, Porto, Portugal
| | - Alberto Caldas Afonso
- Centro Hospitalar Universitário do Porto, Centro Materno-Infantil do Norte, Unidade de Nefrologia Pediátrica, Porto, Portugal.,Universidade do Porto, Instituto de Ciências Biomédicas Abel Salazar, Porto, Portugal.,Universidade do Porto, Instituto de Saúde Pública, Porto, Portugal
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23
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Claudi F, Tyson AL, Petrucco L, Margrie TW, Portugues R, Branco T. Visualizing anatomically registered data with brainrender. eLife 2021; 10:e65751. [PMID: 33739286 PMCID: PMC8079143 DOI: 10.7554/elife.65751] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/17/2021] [Indexed: 11/13/2022] Open
Abstract
Three-dimensional (3D) digital brain atlases and high-throughput brain-wide imaging techniques generate large multidimensional datasets that can be registered to a common reference frame. Generating insights from such datasets depends critically on visualization and interactive data exploration, but this a challenging task. Currently available software is dedicated to single atlases, model species or data types, and generating 3D renderings that merge anatomically registered data from diverse sources requires extensive development and programming skills. Here, we present brainrender: an open-source Python package for interactive visualization of multidimensional datasets registered to brain atlases. Brainrender facilitates the creation of complex renderings with different data types in the same visualization and enables seamless use of different atlas sources. High-quality visualizations can be used interactively and exported as high-resolution figures and animated videos. By facilitating the visualization of anatomically registered data, brainrender should accelerate the analysis, interpretation, and dissemination of brain-wide multidimensional data.
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Affiliation(s)
| | - Adam L Tyson
- UCL Sainsbury Wellcome CentreLondonUnited Kingdom
| | - Luigi Petrucco
- Institute of Neuroscience, Technical University of MunichMunichGermany
- Max Planck Institute of Neurobiology, Research Group of Sensorimotor ControlMartinsriedGermany
| | | | - Ruben Portugues
- Institute of Neuroscience, Technical University of MunichMunichGermany
- Max Planck Institute of Neurobiology, Research Group of Sensorimotor ControlMartinsriedGermany
- Munich Cluster for Systems Neurology (SyNergy)MunichGermany
| | - Tiago Branco
- UCL Sainsbury Wellcome CentreLondonUnited Kingdom
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24
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Cardoso A, Gonçalves L, Inácio JR, Cunha F, Freitas JV, Soares R, Branco C, Branco T, Jacinto N, Santos LR, Alvoeiro L, Lacerda APD. Bird Fancier's Lung Diagnosis in Times of COVID-19. Arch Bronconeumol 2021; 57:90-91. [PMID: 34629679 PMCID: PMC7577872 DOI: 10.1016/j.arbres.2020.09.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Ana Cardoso
- Department of Medicine 2, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Lisa Gonçalves
- Department of Medicine 2, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - João R Inácio
- Department of Imagiology, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Francisco Cunha
- Department of Medicine 2, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - João Victor Freitas
- Department of Medicine 2, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Raquel Soares
- Department of Medicine 2, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Carolina Branco
- Department of Medicine 2, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Tiago Branco
- Department of Medicine 2, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Nuno Jacinto
- Department of Medicine 2, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Liliana R Santos
- Department of Medicine 2, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Lourdes Alvoeiro
- Department of Medicine 2, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - António Pais de Lacerda
- Department of Medicine 2, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
- Faculty of Medicine of the University of Lisbon, Lisbon
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25
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Abstract
Escape is one of the most studied animal behaviors, and there is a rich normative theory that links threat properties to evasive actions and their timing. The behavioral principles of escape are evolutionarily conserved and rely on elementary computational steps such as classifying sensory stimuli and executing appropriate movements. These are common building blocks of general adaptive behaviors. Here we consider the computational challenges required for escape behaviors to be implemented, discuss possible algorithmic solutions, and review some of the underlying neural circuits and mechanisms. We outline shared neural principles that can be implemented by evolutionarily ancient neural systems to generate escape behavior, to which cortical encephalization has been added to allow for increased sophistication and flexibility in responding to threat.
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Affiliation(s)
- Tiago Branco
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London W1T 4JG, United Kingdom
| | - Peter Redgrave
- Department of Psychology, The University of Sheffield, Sheffield S1 2LT, United Kingdom
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26
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Gameiro J, Branco T, Lopes JA. Artificial Intelligence in Acute Kidney Injury Risk Prediction. J Clin Med 2020; 9:jcm9030678. [PMID: 32138284 PMCID: PMC7141311 DOI: 10.3390/jcm9030678] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 02/26/2020] [Accepted: 02/28/2020] [Indexed: 12/23/2022] Open
Abstract
Acute kidney injury (AKI) is a frequent complication in hospitalized patients, which is associated with worse short and long-term outcomes. It is crucial to develop methods to identify patients at risk for AKI and to diagnose subclinical AKI in order to improve patient outcomes. The advances in clinical informatics and the increasing availability of electronic medical records have allowed for the development of artificial intelligence predictive models of risk estimation in AKI. In this review, we discussed the progress of AKI risk prediction from risk scores to electronic alerts to machine learning methods.
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Affiliation(s)
- Joana Gameiro
- Division of Nephrology and Renal Transplantation, Department of Medicine, Centro Hospitalar Lisboa Norte, EPE, Av. Prof. Egas Moniz, 1649-035 Lisboa, Portugal;
- Correspondence:
| | - Tiago Branco
- Department of Medicine, Centro Hospitalar Lisboa Norte, EPE, Av. Prof. Egas Moniz, 1649-035 Lisboa, Portugal;
| | - José António Lopes
- Division of Nephrology and Renal Transplantation, Department of Medicine, Centro Hospitalar Lisboa Norte, EPE, Av. Prof. Egas Moniz, 1649-035 Lisboa, Portugal;
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27
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Lefler Y, Campagner D, Branco T. The role of the periaqueductal gray in escape behavior. Curr Opin Neurobiol 2019; 60:115-121. [PMID: 31864105 DOI: 10.1016/j.conb.2019.11.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 11/18/2019] [Accepted: 11/20/2019] [Indexed: 02/01/2023]
Abstract
Escape behavior is a defensive action deployed by animals in response to imminent threats. In mammalian species, a variety of different brain circuits are known to participate in this crucial survival behavior. One of these circuits is the periaqueductal gray, a midbrain structure that can command a variety of instinctive behaviors. Recent experiments using modern systems neuroscience techniques have begun to elucidate the specific role of the periaqueductal gray in controlling escape. These have shown that periaqueductal gray neurons are crucial units for gating and commanding the initiation of escape, specifically activated in situations of imminent, escapable threat. In addition, it is becoming clear that the periaqueductal gray integrates brain-wide information that can modulate escape initiation to generate flexible defensive behaviors.
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Affiliation(s)
- Yaara Lefler
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London W1T 4JG, UK
| | - Dario Campagner
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London W1T 4JG, UK; UCL Gatsby Computational Neuroscience Unit, London W1T 4JG, UK
| | - Tiago Branco
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London W1T 4JG, UK.
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28
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Ujfalussy BB, Makara JK, Lengyel M, Branco T. Global and Multiplexed Dendritic Computations under In Vivo-like Conditions. Neuron 2019; 100:579-592.e5. [PMID: 30408443 PMCID: PMC6226578 DOI: 10.1016/j.neuron.2018.08.032] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 07/07/2018] [Accepted: 08/21/2018] [Indexed: 10/27/2022]
Abstract
Dendrites integrate inputs nonlinearly, but it is unclear how these nonlinearities contribute to the overall input-output transformation of single neurons. We developed statistically principled methods using a hierarchical cascade of linear-nonlinear subunits (hLN) to model the dynamically evolving somatic response of neurons receiving complex, in vivo-like spatiotemporal synaptic input patterns. We used the hLN to predict the somatic membrane potential of an in vivo-validated detailed biophysical model of a L2/3 pyramidal cell. Linear input integration with a single global dendritic nonlinearity achieved above 90% prediction accuracy. A novel hLN motif, input multiplexing into parallel processing channels, could improve predictions as much as conventionally used additional layers of local nonlinearities. We obtained similar results in two other cell types. This approach provides a data-driven characterization of a key component of cortical circuit computations: the input-output transformation of neurons during in vivo-like conditions.
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Affiliation(s)
- Balázs B Ujfalussy
- MRC Laboratory of Molecular Biology, Cambridge, UK; Laboratory of Neuronal Signaling, Institute of Experimental Medicine, Budapest, Hungary; Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge, UK; MTA Wigner Research Center for Physics, Budapest, Hungary.
| | - Judit K Makara
- Laboratory of Neuronal Signaling, Institute of Experimental Medicine, Budapest, Hungary
| | - Máté Lengyel
- Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge, UK; Department of Cognitive Science, Central European University, Budapest, Hungary
| | - Tiago Branco
- MRC Laboratory of Molecular Biology, Cambridge, UK; Sainsbury Wellcome Centre, University College London, London, UK
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29
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Abstract
When faced with potential predators, animals instinctively decide whether there is a threat they should escape from, and also when, how, and where to take evasive action. While escape is often viewed in classical ethology as an action that is released upon presentation of specific stimuli, successful and adaptive escape behaviour relies on integrating information from sensory systems, stored knowledge, and internal states. From a neuroscience perspective, escape is an incredibly rich model that provides opportunities for investigating processes such as perceptual and value-based decision-making, or action selection, in an ethological setting. We review recent research from laboratory and field studies that explore, at the behavioural and mechanistic levels, how elements from multiple information streams are integrated to generate flexible escape behaviour.
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Affiliation(s)
- Dominic A Evans
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, UCL, London, UK; These authors contributed equally to this work
| | - A Vanessa Stempel
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, UCL, London, UK; These authors contributed equally to this work
| | - Ruben Vale
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, UCL, London, UK; These authors contributed equally to this work
| | - Tiago Branco
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, UCL, London, UK.
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30
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Masaracchia C, Hnida M, Gerhardt E, Lopes da Fonseca T, Villar-Pique A, Branco T, Stahlberg MA, Dean C, Fernández CO, Milosevic I, Outeiro TF. Membrane binding, internalization, and sorting of alpha-synuclein in the cell. Acta Neuropathol Commun 2018; 6:79. [PMID: 30107856 PMCID: PMC6090819 DOI: 10.1186/s40478-018-0578-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 07/28/2018] [Indexed: 12/31/2022] Open
Abstract
Alpha-synuclein (aSyn) plays a crucial role in Parkinson's disease (PD) and other synucleinopathies, since it misfolds and accumulates in typical proteinaceous inclusions. While the function of aSyn is thought to be related to vesicle binding and trafficking, the precise molecular mechanisms linking aSyn with synucleinopathies are still obscure. aSyn can spread in a prion-like manner between interconnected neurons, contributing to the propagation of the pathology and to the progressive nature of synucleinopathies. Here, we investigated the interaction of aSyn with membranes and trafficking machinery pathways using cellular models of PD that are amenable to detailed molecular analyses. We found that different species of aSyn can enter cells and form high molecular weight species, and that membrane binding properties are important for the internalization of aSyn. Once internalized, aSyn accumulates in intracellular inclusions. Interestingly, we found that internalization is blocked in the presence of dynamin inhibitors (blocked membrane scission), suggesting the involvement of the endocytic pathway in the internalization of aSyn. By screening a pool of small Rab-GTPase proteins (Rabs) which regulate membrane trafficking, we found that internalized aSyn partially colocalized with Rab5A and Rab7. Initially, aSyn accumulated in Rab4A-labelled vesicles and, at later stages, it reached the autophagy-lysosomal pathway (ALP) where it gets degraded. In total, our study emphasizes the importance of membrane binding, not only as part of the normal function but also as an important step in the internalization and subsequent accumulation of aSyn. Importantly, we identified a fundamental role for Rab proteins in the modulation of aSyn processing, clearance and spreading, suggesting that targeting Rab proteins may hold important therapeutic value in PD and other synucleinopathies.
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31
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Abstract
Evolution has selected a repertoire of defensive behaviors that are essential for survival across all animal species. These behaviors are often stereotyped actions elicited in response to innately aversive sensory stimuli, but their success requires enough flexibility for adapting to different spatial environments, which can change rapidly. Here, we describe a behavioral assay to evaluate the influence of learned spatial knowledge on defensive behaviors in mice. We have adapted the widely used Barnes maze spatial memory assay to investigate how mice navigate to a shelter during escape responses to innately aversive sensory stimuli in a novel environment, and how they adapt to acute changes in the environment. This new assay is an ethological paradigm that does not require training and exploits the natural exploration patterns and navigation strategies in mice. We propose that the set of protocols described here are a powerful means of studying goal-directed behaviors and stimulus-triggered navigation, which should be of interest to both the fields of instinctive behaviors and spatial memory.
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Affiliation(s)
- Ruben Vale
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour; MRC Laboratory of Molecular Biology
| | - Dominic Evans
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour; MRC Laboratory of Molecular Biology
| | - Tiago Branco
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour; MRC Laboratory of Molecular Biology;
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32
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Grillo FW, Neves G, Walker A, Vizcay-Barrena G, Fleck RA, Branco T, Burrone J. A Distance-Dependent Distribution of Presynaptic Boutons Tunes Frequency-Dependent Dendritic Integration. Neuron 2018; 99:275-282.e3. [PMID: 29983327 PMCID: PMC6078905 DOI: 10.1016/j.neuron.2018.06.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 03/23/2018] [Accepted: 06/08/2018] [Indexed: 11/28/2022]
Abstract
How presynaptic inputs and neurotransmitter release dynamics are distributed along a dendritic tree is not well established. Here, we show that presynaptic boutons that form onto basal dendrites of CA1 pyramidal neurons display a decrease in active zone (AZ) size with distance from the soma, resulting in a distance-dependent increase in short-term facilitation. Our findings suggest that the spatial distribution of short-term facilitation serves to compensate for the electrotonic attenuation of subthreshold distal inputs during repeated stimulation and fine-tunes the preferred input frequency of dendritic domains. Presynaptic inputs decrease in size with distance along CA1 basal dendrites Release probability decreases with distance along basal dendrites Short-term facilitation increases with distance along basal dendrites Increased synaptic facilitation offsets passive decay and boosts supralinear events
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Affiliation(s)
- Federico W Grillo
- Centre for Developmental Neurobiology, Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, UK; MRC Centre for Neurodevelopmental Disorders, Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, UK
| | - Guilherme Neves
- Centre for Developmental Neurobiology, Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, UK; MRC Centre for Neurodevelopmental Disorders, Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, UK
| | - Alison Walker
- Centre for Developmental Neurobiology, Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, UK
| | - Gema Vizcay-Barrena
- Centre for Ultrastructural Imaging (CUI), Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, UK
| | - Roland A Fleck
- Centre for Ultrastructural Imaging (CUI), Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, UK
| | - Tiago Branco
- The Sainsbury Wellcome Centre, University College London, 25 Howland Street, London, W1T 4JG, UK
| | - Juan Burrone
- Centre for Developmental Neurobiology, Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, UK; MRC Centre for Neurodevelopmental Disorders, Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, UK.
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33
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Abstract
Escaping from imminent danger is an instinctive behaviour that is fundamental for survival, and requires the classification of sensory stimuli as harmless or threatening. The absence of threat enables animals to forage for essential resources, but as the level of threat and potential for harm increases, they have to decide whether or not to seek safety 1 . Despite previous work on instinctive defensive behaviours in rodents2-11, little is known about how the brain computes the threat level for initiating escape. Here we show that the probability and vigour of escape in mice scale with the saliency of innate threats, and are well described by a model that computes the distance between the threat level and an escape threshold. Calcium imaging and optogenetics in the midbrain of freely behaving mice show that the activity of excitatory neurons in the deep layers of the medial superior colliculus (mSC) represents the saliency of the threat stimulus and is predictive of escape, whereas glutamatergic neurons of the dorsal periaqueductal grey (dPAG) encode exclusively the choice to escape and control escape vigour. We demonstrate a feed-forward monosynaptic excitatory connection from mSC to dPAG neurons, which is weak and unreliable-yet required for escape behaviour-and provides a synaptic threshold for dPAG activation and the initiation of escape. This threshold can be overcome by high mSC network activity because of short-term synaptic facilitation and recurrent excitation within the mSC, which amplifies and sustains synaptic drive to the dPAG. Therefore, dPAG glutamatergic neurons compute escape decisions and escape vigour using a synaptic mechanism to threshold threat information received from the mSC, and provide a biophysical model of how the brain performs a critical behavioural computation.
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Affiliation(s)
- Dominic A Evans
- MRC Laboratory of Molecular Biology, Cambridge, UK
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK
| | - A Vanessa Stempel
- MRC Laboratory of Molecular Biology, Cambridge, UK
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK
| | - Ruben Vale
- MRC Laboratory of Molecular Biology, Cambridge, UK
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK
| | - Sabine Ruehle
- MRC Laboratory of Molecular Biology, Cambridge, UK
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK
| | - Yaara Lefler
- MRC Laboratory of Molecular Biology, Cambridge, UK
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK
| | - Tiago Branco
- MRC Laboratory of Molecular Biology, Cambridge, UK.
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, UK.
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34
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Dos Santos MP, Do Vale MM, Branco T, Klein DR, Santos JPA. HEAT STRESS IN BROILERS AND THE NEED OF CLIMATIZATION SYSTEMS. Revista Brasileira de Engenharia de Biossistemas 2017. [DOI: 10.18011/bioeng2017v11n3p265-272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Broilers have better production rates when housed in thermal comfort conditions, outside of this zone the poultry need to maintain homeothermy. The heat production and thermal exchanges are related to body weight and available surface for heat exchange. The genetic evolution of broilers ensured high production with improvement in the feed conversion and reducing the slaughter time. The faster weight gain difficult sensible heat exchange, increasing the needs for climatization systems, in days with high temperatures. Changes in heat waves frequency and days with extreme temperatures are challenging situations for ventilation and evaporative cooling systems in broiler facilities. This review discusses heat exchanges of broilers and the challenges in maintaining the thermal comfort zone in poultry facilities, in a reality of increase of heat stress conditions.
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Affiliation(s)
| | | | - T. Branco
- Federal University of Santa Maria, Santa Maria – RS, Brazil
| | - D. R. Klein
- Federal University of Paraná, Curitiba – PR, Brazil
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35
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Schmidt-Hieber C, Toleikyte G, Aitchison L, Roth A, Clark BA, Branco T, Häusser M. Active dendritic integration as a mechanism for robust and precise grid cell firing. Nat Neurosci 2017. [PMID: 28628104 DOI: 10.1038/nn.4582] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Understanding how active dendrites are exploited for behaviorally relevant computations is a fundamental challenge in neuroscience. Grid cells in medial entorhinal cortex are an attractive model system for addressing this question, as the computation they perform is clear: they convert synaptic inputs into spatially modulated, periodic firing. Whether active dendrites contribute to the generation of the dual temporal and rate codes characteristic of grid cell output is unknown. We show that dendrites of medial entorhinal cortex neurons are highly excitable and exhibit a supralinear input-output function in vitro, while in vivo recordings reveal membrane potential signatures consistent with recruitment of active dendritic conductances. By incorporating these nonlinear dynamics into grid cell models, we show that they can sharpen the precision of the temporal code and enhance the robustness of the rate code, thereby supporting a stable, accurate representation of space under varying environmental conditions. Our results suggest that active dendrites may therefore constitute a key cellular mechanism for ensuring reliable spatial navigation.
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Affiliation(s)
- Christoph Schmidt-Hieber
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.,Institut Pasteur, Paris, France
| | - Gabija Toleikyte
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Laurence Aitchison
- Gatsby Computational Neuroscience Unit, University College London, London, UK
| | - Arnd Roth
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Beverley A Clark
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Tiago Branco
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.,Sainsbury Wellcome Centre, University College London, London, UK
| | - Michael Häusser
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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36
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Abstract
Instinctive defensive behaviors are essential for animal survival. Across the animal kingdom, there are sensory stimuli that innately represent threat and trigger stereotyped behaviors such as escape or freezing [1-4]. While innate behaviors are considered to be hard-wired stimulus-responses [5], they act within dynamic environments, and factors such as the properties of the threat [6-9] and its perceived intensity [1, 10, 11], access to food sources [12-14], and expectations from past experience [15, 16] have been shown to influence defensive behaviors, suggesting that their expression can be modulated. However, despite recent work [2, 4, 17-21], little is known about how flexible mouse innate defensive behaviors are and how quickly they can be modified by experience. To address this, we have investigated the dependence of escape behavior on learned knowledge about the spatial environment and how the behavior is updated when the environment changes acutely. Using behavioral assays with innately threatening visual and auditory stimuli, we show that the primary goal of escape in mice is to reach a previously memorized shelter location. Memory of the escape target can be formed in a single shelter visit lasting less than 20 s, and changes in the spatial environment lead to a rapid update of the defensive action, including changing the defensive strategy from escape to freezing. Our results show that although there are innate links between specific sensory features and defensive behavior, instinctive defensive actions are surprisingly flexible and can be rapidly updated by experience to adapt to changing spatial environments.
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Affiliation(s)
- Ruben Vale
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK; UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, Howland Street, London W1T 4JG, UK
| | - Dominic A Evans
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK; UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, Howland Street, London W1T 4JG, UK
| | - Tiago Branco
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK; UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, Howland Street, London W1T 4JG, UK.
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37
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Real C, Sobreira Fernandes D, Sá Couto P, Correia de Barros F, Esteves S, Aragão I, Fonseca L, Aguiar J, Branco T, Fernandes Moreira Z. Survival Predictors in Liver Transplantation: Time-Varying Effect of Red Blood Cell Transfusion. Transplant Proc 2017; 48:3303-3306. [PMID: 27931573 DOI: 10.1016/j.transproceed.2016.08.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 08/01/2016] [Accepted: 08/22/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Many attempts have been undertaken to better predict outcome after liver transplantation. The aim of this study was to identify the pre- and intraoperative variables that may influence the survival after liver transplantation, at a single institution. METHODS Anesthetic records from 543 consecutive patients who underwent liver transplantation from June 2006 to June 2014 were reviewed in this retrospective study. Patients undergoing retransplantation were excluded from the analysis, as were patients with familial amyloid polyneuropathy. Preoperative variables studied were age, sex, Model for End-Stage Liver Disease score, primary diagnosis, cold ischemia time, preoperative international normalized ratio, serum albumin, and and hemoglobin levels. Intraoperative variables included were norepinephrine consumption, blood loss, red blood cell transfusion, and surgical time. Variables significant in the univariate analysis with a P value of <.2 were included in a multivariate Cox regression model. RESULTS Only red blood cell transfusion (hazard ratio [HR], 1.16; 95% confidence interval [CI], 1.04-1.29) and female sex (HR, 1.71; 95% CI, 1.10-2.65) were identified as significant independent predictors for survival after liver transplantation. Because of proportionality assumption violation, the multivariate Cox regression model was subsequently upgraded by adding a time-varying interaction between red blood cell transfusion and time since liver transplantation. As a result, we found that at 3 months after liver transplantation, the rate of dying increased 14% (95% CI, 2%-26%) for each unit transfused, and at 6 months it increased 12% (95% CI, 0.3%-24%). CONCLUSIONS Red blood cell transfusion ceased to influence survival from 1 year onward.
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Affiliation(s)
- C Real
- Department of Anesthesiology, Intensive Care, and Emergency Medicine, Centro Hospitalar do Porto, Porto, Portugal.
| | - D Sobreira Fernandes
- Department of Anesthesiology, Intensive Care, and Emergency Medicine, Centro Hospitalar do Porto, Porto, Portugal
| | - P Sá Couto
- Department of Anesthesiology, Intensive Care, and Emergency Medicine, Centro Hospitalar do Porto, Porto, Portugal
| | - F Correia de Barros
- Department of Anesthesiology, Intensive Care, and Emergency Medicine, Centro Hospitalar do Porto, Porto, Portugal
| | - S Esteves
- Department of Anesthesiology, Intensive Care, and Emergency Medicine, Centro Hospitalar do Porto, Porto, Portugal
| | - I Aragão
- Department of Anesthesiology, Intensive Care, and Emergency Medicine, Centro Hospitalar do Porto, Porto, Portugal
| | - L Fonseca
- Department of Anesthesiology, Intensive Care, and Emergency Medicine, Centro Hospitalar do Porto, Porto, Portugal
| | - J Aguiar
- Department of Anesthesiology, Intensive Care, and Emergency Medicine, Centro Hospitalar do Porto, Porto, Portugal
| | - T Branco
- Department of Anesthesiology, Intensive Care, and Emergency Medicine, Centro Hospitalar do Porto, Porto, Portugal
| | - Z Fernandes Moreira
- Department of Anesthesiology, Intensive Care, and Emergency Medicine, Centro Hospitalar do Porto, Porto, Portugal
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Lagarto F, Gomes B, Couto PS, Correia de Barros F, Moreira Z, Branco T, Fonseca L, Aguiar J, Aragão I, Miranda HP, Daniel J, Esteves S. Perioperative Predictors of Survival After Liver Transplantation for Familial Amyloid Polyneuropathy in a Portuguese Center. Transplant Proc 2017; 48:2098-101. [PMID: 27569952 DOI: 10.1016/j.transproceed.2016.04.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/05/2016] [Accepted: 04/27/2016] [Indexed: 11/25/2022]
Abstract
BACKGROUND Liver transplantation (LT) has been the treatment of choice to halt the progression of familial amyloid polyneuropathy (FAP). Few studies have identified prognostic factors for post-LT survival in FAP. Our aim was to assess survival rate and to identify independent factors for survival after LT. METHODS This retrospective cohort study of FAP patients transplanted for the first time analyzed 116 transplantations from 2006 to 2014. The median follow-up period was 45.5 months. RESULTS The overall survival rates at 1 month, 1 year, and 5 years were 89%, 82% and 79%, respectively. On multivariate analysis, only number of red blood cell (RBC) units transfused during surgery, operation time, and body mass index were independent prognostic factors for patient survival. Only 30% of patients were transfused during surgery, and, in these, each RBC unit transfused increased mortality by 53%. The operation time increased mortality by 20% for every 15 minutes of surgery. CONCLUSIONS This study suggests that operation time and RBC transfused are predominant factors affecting post-LT survival in our FAP patients.
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Affiliation(s)
- F Lagarto
- Department of Anesthesiology, Intensive Care, and Emergency, Centro Hospitalar do Porto, Porto, Portugal.
| | - B Gomes
- Department of Anesthesiology, Intensive Care, and Emergency, Centro Hospitalar do Porto, Porto, Portugal
| | - P Sá Couto
- Department of Anesthesiology, Intensive Care, and Emergency, Centro Hospitalar do Porto, Porto, Portugal
| | - F Correia de Barros
- Department of Anesthesiology, Intensive Care, and Emergency, Centro Hospitalar do Porto, Porto, Portugal
| | - Z Moreira
- Department of Anesthesiology, Intensive Care, and Emergency, Centro Hospitalar do Porto, Porto, Portugal
| | - T Branco
- Department of Anesthesiology, Intensive Care, and Emergency, Centro Hospitalar do Porto, Porto, Portugal
| | - L Fonseca
- Department of Anesthesiology, Intensive Care, and Emergency, Centro Hospitalar do Porto, Porto, Portugal
| | - J Aguiar
- Department of Anesthesiology, Intensive Care, and Emergency, Centro Hospitalar do Porto, Porto, Portugal
| | - I Aragão
- Department of Anesthesiology, Intensive Care, and Emergency, Centro Hospitalar do Porto, Porto, Portugal
| | - H P Miranda
- Department of Liver Transplantation, Centro Hospitalar do Porto, Porto, Portugal
| | - J Daniel
- Department of Liver Transplantation, Centro Hospitalar do Porto, Porto, Portugal
| | - S Esteves
- Department of Anesthesiology, Intensive Care, and Emergency, Centro Hospitalar do Porto, Porto, Portugal; Department of Liver Transplantation, Centro Hospitalar do Porto, Porto, Portugal
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Branco T, Tozer A, Magnus CJ, Sugino K, Tanaka S, Lee AK, Wood JN, Sternson SM. Near-Perfect Synaptic Integration by Nav1.7 in Hypothalamic Neurons Regulates Body Weight. Cell 2017; 165:1749-1761. [PMID: 27315482 PMCID: PMC4912688 DOI: 10.1016/j.cell.2016.05.019] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 03/27/2016] [Accepted: 04/26/2016] [Indexed: 01/20/2023]
Abstract
Neurons are well suited for computations on millisecond timescales, but some neuronal circuits set behavioral states over long time periods, such as those involved in energy homeostasis. We found that multiple types of hypothalamic neurons, including those that oppositely regulate body weight, are specialized as near-perfect synaptic integrators that summate inputs over extended timescales. Excitatory postsynaptic potentials (EPSPs) are greatly prolonged, outlasting the neuronal membrane time-constant up to 10-fold. This is due to the voltage-gated sodium channel Nav1.7 (Scn9a), previously associated with pain-sensation but not synaptic integration. Scn9a deletion in AGRP, POMC, or paraventricular hypothalamic neurons reduced EPSP duration, synaptic integration, and altered body weight in mice. In vivo whole-cell recordings in the hypothalamus confirmed near-perfect synaptic integration. These experiments show that integration of synaptic inputs over time by Nav1.7 is critical for body weight regulation and reveal a mechanism for synaptic control of circuits regulating long term homeostatic functions. Hypothalamic neurons that regulate body weight are near-perfect synaptic integrators Near-perfect synaptic integration is observed in hypothalamic neurons in vivo Near-perfect synaptic integration depends on the voltage-gated sodium channel Nav1.7 Loss of Nav1.7 in hypothalamic neurons disrupts regulation of body weight
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Affiliation(s)
- Tiago Branco
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA; Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, UK.
| | - Adam Tozer
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Christopher J Magnus
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Ken Sugino
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Shinsuke Tanaka
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Albert K Lee
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - John N Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Scott M Sternson
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA.
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Klein DR, Vale MM, Silva LP, Santos JPA, Branco T, Fernandes MO. Bioimpedance as a Non-Invasive Method to Evaluate Eggs and Poultry. Rev Bras Cienc Avic 2016. [DOI: 10.1590/1806-9061-2015-0087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- DR Klein
- Federal University of Santa Maria, Brazil
| | - MM Vale
- Federal University of Paraná, Brazil
| | - LP Silva
- Federal University of Santa Maria, Brazil
| | - JPA Santos
- Federal University of Santa Maria, Brazil
| | - T Branco
- Federal University of Santa Maria, Brazil
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Mussini C, Antinori A, Bhagani S, Branco T, Brostrom M, Dedes N, Bereczky T, Girardi E, Gökengin D, Horban A, Lacombe K, Lundgren JD, Mendao L, Mocroft A, Oprea C, Porter K, Podlekareva D, Battegay M, d'Arminio Monforte A. European AIDS Clinical Society Standard of Care meeting on HIV and related coinfections: The Rome Statements. HIV Med 2015; 17:445-52. [PMID: 26492497 DOI: 10.1111/hiv.12347] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2015] [Indexed: 11/27/2022]
Abstract
OBJECTIVES The objective of the 1st European AIDS Clinical Society meeting on Standard of Care in Europe was to raise awareness of the European scenario and come to an agreement on actions that could be taken in the future. METHODS Data-driven presentations were given on specific topics followed by interactive panel discussions. RESULTS In Eastern European countries, the epidemic is largely driven by injecting drug use, in contrast with Western Europe where the infection mainly occurs through heterosexual contact. A high proportion of people living with HIV remain unaware of their infection. Substantial differences exist in Eastern Europe and Central Asia with respect to treatment coverage, regimen availability and continuity of drug supply. In 2012, tuberculosis case notification rates were 5-10 times higher in Eastern Europe compared with Western Europe, with an alarming proportion of newly diagnosed multi-drug-resistant cases. Hepatitis C is widespread in selected geographical areas and risk groups. CONCLUSIONS The key conclusion from the meeting was that a high-priority group of actions could be identified, including: increasing HIV awareness and testing, improving training for health care providers, ensuring equitable patient access to treatments and diagnostics for HIV and comorbidities, and implementing best practices in infection control and treatment of HIV-infected patients coinfected with tuberculosis and hepatitis C virus, for whom direct acting antiviral treatment. should be considered.
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Affiliation(s)
- C Mussini
- University of Modena and Reggio Emilia, Modena, Italy
| | - A Antinori
- National Institute for Infectious Disease 'L. Spallanzani', Rome, Italy
| | - S Bhagani
- University College London, London, UK
| | - T Branco
- Department of Infectious Diseases, Hospital Center, Lisbon, Portugal
| | | | | | | | - E Girardi
- National Institute for Infectious Disease 'L. Spallanzani', Rome, Italy
| | | | - A Horban
- Warsaw Medical University and Hospital of Infectious Diseases, Warsaw, Poland
| | | | - J D Lundgren
- Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | | | - A Mocroft
- University College London, London, UK
| | - C Oprea
- Victor Babes Hospital, Bucharest, Romania
| | - K Porter
- University College London, London, UK
| | - D Podlekareva
- Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - M Battegay
- University Hospital of Basel, Basel, Switzerland
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Henry FE, Sugino K, Tozer A, Branco T, Sternson SM. Cell type-specific transcriptomics of hypothalamic energy-sensing neuron responses to weight-loss. eLife 2015; 4. [PMID: 26329458 PMCID: PMC4595745 DOI: 10.7554/elife.09800] [Citation(s) in RCA: 163] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/02/2015] [Indexed: 12/13/2022] Open
Abstract
Molecular and cellular processes in neurons are critical for sensing and responding to energy deficit states, such as during weight-loss. Agouti related protein (AGRP)-expressing neurons are a key hypothalamic population that is activated during energy deficit and increases appetite and weight-gain. Cell type-specific transcriptomics can be used to identify pathways that counteract weight-loss, and here we report high-quality gene expression profiles of AGRP neurons from well-fed and food-deprived young adult mice. For comparison, we also analyzed Proopiomelanocortin (POMC)-expressing neurons, an intermingled population that suppresses appetite and body weight. We find that AGRP neurons are considerably more sensitive to energy deficit than POMC neurons. Furthermore, we identify cell type-specific pathways involving endoplasmic reticulum-stress, circadian signaling, ion channels, neuropeptides, and receptors. Combined with methods to validate and manipulate these pathways, this resource greatly expands molecular insight into neuronal regulation of body weight, and may be useful for devising therapeutic strategies for obesity and eating disorders. DOI:http://dx.doi.org/10.7554/eLife.09800.001 Humans and other animals must get adequate nutrition in order to survive. As a result, the body has several systems that work side by side to maintain a healthy body weight and ensure that enough food gets eaten to provide the energy that the body needs. Problems with these systems can contribute towards obesity and other eating disorders. Certain types of cells in the brain play important roles in controlling weight and appetite, although the genes and cellular mechanisms that underlie these abilities are not well understood. When an animal is deprived of food, so-called AGRP neurons produce molecules that increase appetite and make it easier to gain weight. These neurons also go through structural changes and increase their electrical activity during weight loss. Another group of cells, called the POMC neurons, becomes less active when an animal is deprived of energy. Using a technique called cell type-specific transcriptomics, Henry, Sugino et al. have now revealed that the expression of hundreds of genes in AGRP and POMC neurons changes depending on whether mice are well fed or food deprived. Food deprivation also affects more genes in AGRP neurons than has been seen in other types of brain cell, and the AGRP neurons are also more sensitive to a change in food intake than POMC neurons. In the future, this gene expression data and knowledge of the pathways affected by the genes could help researchers to develop new treatments for obesity and other disorders that affect appetite. Henry, Sugino et al. then mapped how these changes in gene expression trigger molecular “pathways” in the neurons that alter how the cells work. These affect many parts of the cells, including ion channels, transcription factors, receptors, and secreted proteins. In addition, food deprivation activated pathways in AGRP neurons that protect the cells from damage and death caused by elevated neuron activity and also triggered signaling pathways that increase body weight. In the future, this gene expression data and knowledge of the pathways affected by the genes could help researchers to develop new treatments for obesity and other disorders that affect appetite. DOI:http://dx.doi.org/10.7554/eLife.09800.002
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Affiliation(s)
- Fredrick E Henry
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Ken Sugino
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Adam Tozer
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Tiago Branco
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Scott M Sternson
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
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Ujfalussy BB, Makara JK, Branco T, Lengyel M. Dendritic nonlinearities are tuned for efficient spike-based computations in cortical circuits. eLife 2015; 4:e10056. [PMID: 26705334 PMCID: PMC4912838 DOI: 10.7554/elife.10056] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 12/23/2015] [Indexed: 01/27/2023] Open
Abstract
Cortical neurons integrate thousands of synaptic inputs in their dendrites in highly nonlinear ways. It is unknown how these dendritic nonlinearities in individual cells contribute to computations at the level of neural circuits. Here, we show that dendritic nonlinearities are critical for the efficient integration of synaptic inputs in circuits performing analog computations with spiking neurons. We developed a theory that formalizes how a neuron's dendritic nonlinearity that is optimal for integrating synaptic inputs depends on the statistics of its presynaptic activity patterns. Based on their in vivo preynaptic population statistics (firing rates, membrane potential fluctuations, and correlations due to ensemble dynamics), our theory accurately predicted the responses of two different types of cortical pyramidal cells to patterned stimulation by two-photon glutamate uncaging. These results reveal a new computational principle underlying dendritic integration in cortical neurons by suggesting a functional link between cellular and systems--level properties of cortical circuits.
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Affiliation(s)
- Balázs B Ujfalussy
- Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge, United Kingdom,Wigner Research Centre for Physics, Hungarian Academy of Sciences, Budapest, Hungary,MRC Laboratory of Molecular Biology, Cambridge, United Kingdom,Lendület Laboratory of Neuronal Signaling, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary,
| | - Judit K Makara
- Lendület Laboratory of Neuronal Signaling, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary,Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Tiago Branco
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom,Wolfson Institute for Biomedical Research, University College London, London, United Kingdom
| | - Máté Lengyel
- Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge, United Kingdom,Department of Cognitive Science, Central European University, Budapest, Hungary
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Kohl J, Ng J, Cachero S, Ciabatti E, Dolan MJ, Sutcliffe B, Tozer A, Ruehle S, Krueger D, Frechter S, Branco T, Tripodi M, Jefferis GSXE. Ultrafast tissue staining with chemical tags. Proc Natl Acad Sci U S A 2014; 111:E3805-14. [PMID: 25157152 PMCID: PMC4246963 DOI: 10.1073/pnas.1411087111] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Genetically encoded fluorescent proteins and immunostaining are widely used to detect cellular and subcellular structures in fixed biological samples. However, for thick or whole-mount tissue, each approach suffers from limitations, including limited spectral flexibility and lower signal or slow speed, poor penetration, and high background labeling, respectively. We have overcome these limitations by using transgenically expressed chemical tags for rapid, even, high-signal and low-background labeling of thick biological tissues. We first construct a platform of widely applicable transgenic Drosophila reporter lines, demonstrating that chemical labeling can accelerate staining of whole-mount fly brains by a factor of 100. Using viral vectors to deliver chemical tags into the mouse brain, we then demonstrate that this labeling strategy works well in mice. Thus this tag-based approach drastically improves the speed and specificity of labeling genetically marked cells in intact and/or thick biological samples.
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Affiliation(s)
- Johannes Kohl
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Julian Ng
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Sebastian Cachero
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Ernesto Ciabatti
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Michael-John Dolan
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Ben Sutcliffe
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Adam Tozer
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Sabine Ruehle
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Daniel Krueger
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Shahar Frechter
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Tiago Branco
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Marco Tripodi
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Gregory S X E Jefferis
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
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Ratnayaka A, Marra V, Bush D, Burden JJ, Branco T, Staras K. Recruitment of resting vesicles into recycling pools supports NMDA receptor-dependent synaptic potentiation in cultured hippocampal neurons. J Physiol 2012; 590:1585-97. [PMID: 22271866 PMCID: PMC3413500 DOI: 10.1113/jphysiol.2011.226688] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Most presynaptic terminals in the central nervous system are characterized by two functionally distinct vesicle populations: a recycling pool, which supports action potential-driven neurotransmitter release via vesicle exocytosis, and a resting pool. The relative proportions of these two pools are highly variable between individual synapses, prompting speculation on their specific relationship, and on the possible functions of the resting pool. Using fluorescence imaging of FM-styryl dyes and synaptophysinI-pHluorin (sypHy) as well as correlative electron microscopy approaches, we show here that Hebbian plasticity-dependent changes in synaptic strength in rat hippocampal neurons can increase the recycling pool fraction at the expense of the resting pool in individual synaptic terminals. This recruitment process depends on NMDA-receptor activation, nitric oxide signalling and calcineurin and is accompanied by an increase in the probability of neurotransmitter release at individual terminals. Blockade of actin-mediated intersynaptic vesicle exchange does not prevent recycling pool expansion demonstrating that vesicle recruitment is intrasynaptic. We propose that the conversion of resting pool vesicles to the functionally recycling pool provides a rapid mechanism to implement long-lasting changes in presynaptic efficacy.
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Affiliation(s)
- Arjuna Ratnayaka
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
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Carvalho AC, Valadas E, França L, Carvalho C, Aleixo MJ, Mendez J, Marques R, Sarmento A, Doroana M, Antunes F, Branco T, Aguas M, Sarmento E Castro R, Lazarus JV, Barros H. Population mobility and the changing epidemics of HIV-2 in Portugal. HIV Med 2011; 13:219-25. [PMID: 22136745 DOI: 10.1111/j.1468-1293.2011.00963.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2011] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Portugal is the European country with the highest frequency of HIV-2 infection, which is mainly concentrated in West Africa. The cumulative number of notified HIV-2 infections in Portugal was 1813 by the end of December 2008. To better characterize the dynamics of HIV-2 infection in the country and to obtain data that may be of use in the prevention of the spread of HIV-2, we evaluated a large pooled sample of patients. PATIENTS AND METHODS Five Portuguese hospitals provided data on HIV-2-infected patients from 1984 to the end of 2007. Data concerning demographic characteristics and clinical variables were extracted. Patients were stratified according to date of diagnosis in approximately 5-year categories. RESULTS The sample included 442 patients, accounting for 37% of all HIV-2 infections notified in Portugal during that period. HIV-2-infected patients showed clearly different characteristics according to the period of diagnosis. Until 2000, the majority of HIV-2-infected patients were Portuguese-born males living in the north of the country. From 2000 to 2007, most of the patients diagnosed with HIV-2 infection had a West African origin, were predominantly female and were living in the capital, Lisbon. The average age at diagnosis and loss to follow-up significantly increased over time. CONCLUSION HIV-2 infection has been documented in Portugal since the early 1980s and its epidemiology appears to reflect changes in population movement. These include the movements of soldiers and repatriates from African territories during the independence wars and, later, migration and mobility from high-endemicity areas. The findings of this study stress the importance of promoting migrant-sensitive health care.
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Affiliation(s)
- A C Carvalho
- Institute of Public Health of the University of Porto, Portugal.
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Ratnayaka A, Marra V, Branco T, Staras K. Extrasynaptic vesicle recycling in mature hippocampal neurons. Nat Commun 2011; 2:531. [PMID: 22068598 DOI: 10.1038/ncomms1534] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 10/05/2011] [Indexed: 11/09/2022] Open
Abstract
Fast neuronal signalling relies on highly regulated vesicle fusion and recycling at specialized presynaptic terminals. Recently, examples of non-classical neurotransmission have also been reported, where fusion of vesicles can occur at sites remote from conventional synapses. This has potentially broad biological implications, but the underlying mechanisms are not well established. Here we show that a complete vesicle recycling pathway can occur at discrete axonal sites in mature hippocampal neurons and that extrasynaptic fusion is a robust feature of native tissue. We demonstrate that laterally mobile vesicle clusters trafficking between synaptic terminals become transiently stabilized by evoked action potentials and undergo complete but delayed Ca(2+)-dependent fusion along axons. This fusion is associated with dynamic actin accumulation and, subsequently, vesicles can be locally recycled, re-acidified and re-used. Immunofluorescence and ultrastructural work demonstrates that extrasynaptic fusion sites can have apposed postsynaptic specializations, suggesting that mobile vesicle recycling may underlie highly dynamic neuron-neuron communication.
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Affiliation(s)
- Arjuna Ratnayaka
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
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Branco T. Eppendorf winner. The language of dendrites. Science 2011; 334:615-6. [PMID: 22053040 DOI: 10.1126/science.1215079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Branco T, Marra V, Staras K. Examining size-strength relationships at hippocampal synapses using an ultrastructural measurement of synaptic release probability. J Struct Biol 2010; 172:203-10. [PMID: 19895891 PMCID: PMC3084449 DOI: 10.1016/j.jsb.2009.10.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 09/25/2009] [Accepted: 10/27/2009] [Indexed: 11/19/2022]
Abstract
Release probability (p(r)) is a fundamental presynaptic parameter which is critical in defining synaptic strength. Knowledge of how synapses set and regulate their p(r) is a fundamental step in understanding synaptic transmission and communication between neurons. Despite its importance, p(r) is difficult to measure directly at single synapses. One important strategy to achieve this has relied on the application of fluorescence-based imaging methods, but this is always limited by the lack of detailed information on the morphological and structural properties of the individual synapses under study, and thus precludes an investigation of the relationship between p(r) and synaptic anatomy. Here we outline a powerful methodology based on using FM-styryl dyes, photoconversion and correlative ultrastructural analysis in dissociated hippocampal cultured neurons, which provides both a direct readout of p(r) as well as nanoscale detail on synaptic organization and structure. We illustrate the value of this approach by investigating, at the level of individual reconstructed terminals, the relationship between release probability and defined vesicle pools. We show that in our population of synapses, p(r) is highly variable, and while it is positively correlated with the number of vesicles docked at the active zone it shows no relationship with the total number of synaptic vesicles. The lack of a direct correlation between total synaptic size and performance in these terminals suggests that factors other than the absolute magnitude of the synapse are the most important determinants of synaptic efficacy.
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Affiliation(s)
- Tiago Branco
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
- Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Vincenzo Marra
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - Kevin Staras
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
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Abstract
The detection and discrimination of temporal sequences is fundamental to brain function and underlies perception, cognition, and motor output. By applying patterned, two-photon glutamate uncaging, we found that single dendrites of cortical pyramidal neurons exhibit sensitivity to the sequence of synaptic activation. This sensitivity is encoded by both local dendritic calcium signals and somatic depolarization, leading to sequence-selective spike output. The mechanism involves dendritic impedance gradients and nonlinear synaptic N-methyl-D-aspartate receptor activation and is generalizable to dendrites in different neuronal types. This enables discrimination of patterns delivered to a single dendrite, as well as patterns distributed randomly across the dendritic tree. Pyramidal cell dendrites can thus act as processing compartments for the detection of synaptic sequences, thereby implementing a fundamental cortical computation.
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Affiliation(s)
- Tiago Branco
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology, and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
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