Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Front Cell Infect Microbiol ; 11: 716592, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34368019

RESUMO

Bacteria modify their morphology in response to various factors including growth stage, nutrient availability, predation, motility and long-term survival strategies. Morphological changes may also be associated with specific physiological phenotypes such as the formation of dormant or persister cells in a "viable but non-culturable" (VBNC) state which frequently display different shapes and size compared to their active counterparts. Such dormancy phenotypes can display various degrees of tolerance to antibiotics and therefore a detailed understanding of these phenotypes is crucial for combatting chronic infections and associated diseases. Cell shape and size are therefore more than simple phenotypic characteristics; they are important physiological properties for understanding bacterial life-strategies and pathologies. However, quantitative studies on the changes to cell morphologies during bacterial growth, persister cell formation and the VBNC state are few and severely constrained by current limitations in the most used investigative techniques of flow cytometry (FC) and light or electron microscopy. In this study, we applied high-throughput Imaging Flow Cytometry (IFC) to characterise and quantify, at single-cell level and over time, the phenotypic heterogeneity and morphological changes in cultured populations of four bacterial species, Bacillus subtilis, Lactiplantibacillus plantarum, Pediococcus acidilactici and Escherichia coli. Morphologies in relation to growth stage and stress responses, cell integrity and metabolic activity were analysed. Additionally, we were able to identify and morphologically classify dormant cell phenotypes such as VBNC cells and monitor the resuscitation of persister cells in Escherichia coli following antibiotic treatment. We therefore demonstrate that IFC, with its high-throughput data collection and image capture capabilities, provides a platform by which a detailed understanding of changes in bacterial phenotypes and their physiological implications may be accurately monitored and quantified, leading to a better understanding of the role of phenotypic heterogeneity in the dynamic microbiome.


Assuntos
Bactérias , Escherichia coli , Escherichia coli/genética , Citometria de Fluxo , Viabilidade Microbiana , Fenótipo
2.
Arterioscler Thromb Vasc Biol ; 41(9): 2454-2468, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34261327

RESUMO

Objective: Extracellular vesicles (EVs) facilitate molecular transport across extracellular space, allowing local and systemic signaling during homeostasis and in disease. Extensive studies have described functional roles for EV populations, including during cardiovascular disease, but the in vivo characterization of endogenously produced EVs is still in its infancy. Because of their genetic tractability and live imaging amenability, zebrafish represent an ideal but under-used model to investigate endogenous EVs. We aimed to establish a transgenic zebrafish model to allow the in vivo identification, tracking, and extraction of endogenous EVs produced by different cell types. Approach and Results: Using a membrane-tethered fluorophore reporter system, we show that EVs can be fluorescently labeled in larval and adult zebrafish and demonstrate that multiple cell types including endothelial cells and cardiomyocytes actively produce EVs in vivo. Cell-type specific EVs can be tracked by high spatiotemporal resolution light-sheet live imaging and modified flow cytometry methods allow these EVs to be further evaluated. Additionally, cryo electron microscopy reveals the full morphological diversity of larval and adult EVs. Importantly, we demonstrate the utility of this model by showing that different cell types exchange EVs in the adult heart and that ischemic injury models dynamically alter EV production. Conclusions: We describe a powerful in vivo zebrafish model for the investigation of endogenous EVs in all aspects of cardiovascular biology and pathology. A cell membrane fluorophore labeling approach allows cell-type specific tracing of EV origin without bias toward the expression of individual protein markers and will allow detailed future examination of their function.


Assuntos
Sistema Cardiovascular/metabolismo , Vesículas Extracelulares/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Animais Geneticamente Modificados , Sistema Cardiovascular/embriologia , Separação Celular , Microscopia Crioeletrônica , Modelos Animais de Doenças , Células Endoteliais/metabolismo , Células Endoteliais/ultraestrutura , Vesículas Extracelulares/genética , Vesículas Extracelulares/ultraestrutura , Citometria de Fluxo , Regulação da Expressão Gênica no Desenvolvimento , Larva/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/ultraestrutura , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Tempo , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética
3.
PLoS Pathog ; 17(1): e1009194, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33439894

RESUMO

The viable but non culturable (VBNC) state is a condition in which bacterial cells are viable and metabolically active, but resistant to cultivation using a routine growth medium. We investigated the ability of V. parahaemolyticus to form VBNC cells, and to subsequently become resuscitated. The ability to control VBNC cell formation in the laboratory allowed us to selectively isolate VBNC cells using fluorescence activated cell sorting, and to differentiate subpopulations based on their metabolic activity, cell shape and the ability to cause disease in Galleria mellonella. Our results showed that two subpopulations (P1 and P2) of V. parahaemolyticus VBNC cells exist and can remain dormant in the VBNC state for long periods. VBNC subpopulation P2, had a better fitness for survival under stressful conditions and showed 100% revival under favourable conditions. Proteomic analysis of these subpopulations (at two different time points: 12 days (T12) and 50 days (T50) post VBNC) revealed that the proteome of P2 was more similar to that of the starting microcosm culture (T0) than the proteome of P1. Proteins that were significantly up or down-regulated between the different VBNC populations were identified and differentially regulated proteins were assigned into 23 functional groups, the majority being assigned to metabolism functional categories. A lactate dehydrogenase (lldD) protein, responsible for converting lactate to pyruvate, was significantly upregulated in all subpopulations of VBNC cells. Deletion of the lactate dehydrogenase (RIMD2210633:ΔlldD) gene caused cells to enter the VBNC state significantly more quickly compared to the wild-type, and adding lactate to VBNC cells aided their resuscitation and extended the resuscitation window. Addition of pyruvate to the RIMD2210633:ΔlldD strain restored the wild-type VBNC formation profile. This study suggests that lactate dehydrogenase may play a role in regulating the VBNC state.


Assuntos
Fenômenos Fisiológicos Bacterianos , Proteínas de Bactérias/metabolismo , Viabilidade Microbiana , Proteoma/metabolismo , Vibrio parahaemolyticus/crescimento & desenvolvimento , Vibrio parahaemolyticus/patogenicidade , Virulência , Células Cultivadas , Meios de Cultura , Regulação Bacteriana da Expressão Gênica , Proteoma/análise , Vibrioses/metabolismo , Vibrioses/microbiologia , Vibrio parahaemolyticus/metabolismo
4.
Sci Rep ; 10(1): 20727, 2020 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-33244023

RESUMO

Size is a fundamental cellular trait that is important in determining phytoplankton physiological and ecological processes. Fossil coccospheres, the external calcite structure produced by the excretion of interlocking plates by the phytoplankton coccolithophores, can provide a rare window into cell size in the past. Coccospheres are delicate however and are therefore poorly preserved in sediment. We demonstrate a novel technique combining imaging flow cytometry and cross-polarised light (ISX+PL) to rapidly and reliably visually isolate and quantify the morphological characteristics of coccospheres from marine sediment by exploiting their unique optical and morphological properties. Imaging flow cytometry combines the morphological information provided by microscopy with high sample numbers associated with flow cytometry. High throughput imaging overcomes the constraints of labour-intensive manual microscopy and allows statistically robust analysis of morphological features and coccosphere concentration despite low coccosphere concentrations in sediments. Applying this technique to the fine-fraction of sediments, hundreds of coccospheres can be visually isolated quickly with minimal sample preparation. This approach has the potential to enable rapid processing of down-core sediment records and/or high spatial coverage from surface sediments and may prove valuable in investigating the interplay between climate change and coccolithophore physiological/ecological response.


Assuntos
Citometria de Fluxo/métodos , Sedimentos Geológicos/análise , Microscopia/métodos , Fitoplâncton/isolamento & purificação , Fitoplâncton/fisiologia , Carbonato de Cálcio/química , Fósseis
5.
Artigo em Inglês | MEDLINE | ID: mdl-30687838

RESUMO

Thermoanaerobacter ethanolicus JW 200 has been identified as a potential sustainable biofuel producer due to its ability to readily ferment carbohydrates to ethanol. A hybrid sequencing approach, combining Oxford Nanopore and Illumina DNA sequence reads, was applied to produce a single contiguous genome sequence of 2,911,280 bp.

6.
Environ Geochem Health ; 31(2): 315-25, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19023666

RESUMO

Preliminary mineral magnetic results from a pilot project investigating the suitability of roadside tree leaves as depositories of vehicular pollution are presented. Tree leaf surfaces (Lime: Tilia europaea; Sycamore: Acer pseudoplatanus) at four roadside and one woodland location in Wolverhampton, UK, have been monitored (July 2003 to November 2003). Mineral magnetic technologies have revealed spatial variations of particulate pollution concentration throughout the conurbation and data analysis indicates that magnetic concentration parameters are suitable proxies for fine particulate pollution, which are particularly hazardous to health. Site-specific traffic management and associated vehicle behaviour appear to be chiefly responsible for the magnetic concentration differences between sites. Magneto-biomonitoring in this way allows the high-resolution spatial mapping of particulate matter (PM) pollution, which may also benefit epidemiology in better assessing exposure to vehicular-derived particulates. Given the speed, measurement sensitivity and non-destructive nature of the technique, it is proposed that this low-cost approach offers some advantages over centralised monitoring stations to monitor urban roadside particulate pollution.


Assuntos
Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Folhas de Planta/química , Emissões de Veículos/análise , Acer/química , Cidades , Inglaterra , Magnetismo , Tamanho da Partícula , Tilia/química
7.
Environ Geochem Health ; 31(2): 327-38, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19005766

RESUMO

A regional pollution history has been reconstructed for the borough of Halton (northwest England) from four urban ponds in north Cheshire and south Merseyside, using environmental analyses of lake sediment stratigraphies. Mineral magnetism, geochemistry and radiometric dating have produced profiles of pollution characteristics dating from the mid-nineteenth century to present day. These pollution profiles reflect the atmospheric deposition of a range of pollutants over 150 years of intensified industry. Distinct phases of pollution deposition and characteristics are identified reflecting: (1) intensification of industry in the nineteenth century; (2) expansion of industry during the twentieth century; (3) post 1956 Clean Air Acts. This work promotes the potential use of these pollution archives for use in epidemiology to better understand links between human health and environmental pollution, especially for diseases with long latency times, where retrospective pollution exposure assessments are important.


Assuntos
Poluição do Ar/história , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Abastecimento de Água , Cidades , Inglaterra , Exposição Ambiental/história , Geologia , História do Século XIX , História do Século XX , Humanos , Indústrias/história , Magnetismo
8.
J Cogn Neurosci ; 18(11): 1799-807, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17069471

RESUMO

Preclinical studies have implicated cholinergic neurotransmission, specifically M1 muscarinic acetylcholine receptor (mAChR) activation, in sleep-associated memory consolidation. In the present study, we investigated the effects of administering the direct M1 mAChR agonist RS-86 on pre-post sleep memory consolidation. Twenty healthy human participants were tested in a declarative word-list task and a procedural mirror-tracing task. RS-86 significantly reduced rapid eye movement (REM) sleep latency and slow wave sleep (SWS) duration in comparison with placebo. Presleep acquisition and postsleep recall rates were within the expected ranges. However, recall rates in both tasks were almost identical for the RS-86 and placebo conditions. These results indicate that selective M1 mAChR activation in healthy humans has no clinically relevant effect on pre-post sleep consolidation of declarative or procedural memories at a dose that reduces REM sleep latency and SWS duration.


Assuntos
Rememoração Mental/efeitos dos fármacos , Agonistas Muscarínicos/farmacologia , Sono/efeitos dos fármacos , Succinimidas/farmacologia , Adulto , Método Duplo-Cego , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Humanos , Masculino , Análise Multivariada , Testes Neuropsicológicos , Tempo de Reação/efeitos dos fármacos
9.
ANZ J Surg ; 76(7): 591-5, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16813624

RESUMO

BACKGROUND: In situ disease surrounding invasive tumours is an important consideration in the management of patients with early breast cancer. This study of screen-detected breast cancers assessed the influence of in situ disease including an extensive in situ component (defined as ductal carcinoma in situ involving more than 25% of the area within the invasive tumour) on surgical management, local recurrence and survival of a group of patients. METHODS: A total of 595 cases of invasive breast cancer detected at St Vincent's BreastScreen were retrospectively reviewed to determine presence and extent of in situ disease, the surgical procedure and adequacy of excision. Outcome was examined in a cohort of 126 cases. RESULTS: A total of 438 (74%) patients had in situ foci in or around the invasive tumour and 107 (18%) were defined as extensive in situ component (EIC)-positive. The initial procedure was mastectomy in 20% of the cases and breast-conserving surgery in 80% including 18% who underwent further surgery. Re-excision (P = 0.02) or mastectomy (P = 0.01) was more often required in patients with EIC. After definitive local excision, margins were close or involved with invasive disease in 3% but the patients with EIC were more likely to have margins close or involved with in situ disease (16 vs 2%; P = 0.001). There were seven deaths and one local invasive recurrence in the follow-up group and none of the deaths were in patients who were EIC-positive. CONCLUSIONS: EIC predicts for a higher rate of re-excision and/or mastectomy. For patients with EIC, there is an acceptably low risk of local recurrence if margins are clear.


Assuntos
Neoplasias da Mama/cirurgia , Carcinoma in Situ/cirurgia , Carcinoma Ductal de Mama/cirurgia , Mamografia/métodos , Mastectomia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/diagnóstico por imagem , Carcinoma in Situ/diagnóstico por imagem , Carcinoma Ductal de Mama/diagnóstico por imagem , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
10.
Learn Mem ; 13(1): 27-34, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16452651

RESUMO

Recent studies have reported new evidence consistent with the hypothesis that reactivating a memory by re-exposure to a training context destabilizes the memory and induces "reconsolidation." In the present experiments, rats' memory for inhibitory avoidance (IA) training was tested 6 h (Test 1), 2 d (Test 2), and 6 d (Test 3) after training. On Test 1 the rats were either removed from the shock compartment immediately after entry or retained in the shock context for 200 sec, and intrahippocampal infusions of the protein synthesis inhibitor anisomycin (75 microg/side) were administered immediately after the test. Anisomycin infusions administered after Test 1 impaired IA performance on Test 2 in animals given the brief re-exposure, but impaired extinction in animals exposed to the context for 200 sec. Rats with anisomycin-induced retention impairment on Test 2 demonstrated spontaneous recovery of retention performance on Test 3, whereas rats showing extinction on Test 2 showed further extinction on Test 3. The findings indicate that post-retrieval administration of anisomycin impairs subsequent retention performance only in the absence of extinction and that this impairment is temporary.


Assuntos
Anisomicina/administração & dosagem , Aprendizagem da Esquiva/efeitos dos fármacos , Extinção Psicológica/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Rememoração Mental/efeitos dos fármacos , Inibidores da Síntese de Proteínas/administração & dosagem , Animais , Condicionamento Clássico/efeitos dos fármacos , Esquema de Medicação , Masculino , Ratos , Ratos Sprague-Dawley
12.
Neurobiol Learn Mem ; 80(3): 178-93, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14521862

RESUMO

The central cholinergic system and muscarinic cholinergic receptor (mR) activation have long been associated with cognitive function. Although mR activation is no doubt involved in many aspects of cognitive functioning, the extensive evidence that memory is influenced by cholinergic treatments given after training either systemically or intra-cranially clearly indicates that cholinergic activation via mRs is a critical component in modulation of memory consolidation. Furthermore, the evidence indicates that activation of mRs in the basolateral amygdala (BLA) plays an essential role in enabling other neuromodulatory influences on memory consolidation. Memory can also be affected by posttraining activation of mRs in the hippocampus, striatum and cortex. Evidence of increases in hippocampal and cortical acetylcholine (ACh) levels following learning experiences support the view that endogenous ACh release is involved in long-term memory consolidation. Furthermore, the findings indicating that mR drug treatments influence plasticity in the hippocampus and in sensory cortices strongly suggest that mR activation is involved in the storage of information in these brain regions.


Assuntos
Memória/fisiologia , Receptores Colinérgicos/fisiologia , Receptores Muscarínicos/fisiologia , Tonsila do Cerebelo/metabolismo , Atenção/fisiologia , Núcleo Basal de Meynert/metabolismo , Córtex Cerebral/metabolismo , Hipocampo/metabolismo , Humanos , Plasticidade Neuronal/fisiologia , Receptores Colinérgicos/metabolismo , Receptores Muscarínicos/metabolismo
13.
Ann N Y Acad Sci ; 985: 273-93, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12724165

RESUMO

Memories of emotionally arousing events tend to be more vivid and to persist longer than do memories of neutral or trivial events. Moreover, memories of emotionally influenced information may endure after a single experience. Recent findings strongly suggest that the influence of emotional arousal on memory consolidation is mediated by the release of adrenal stress hormones (epinephrine and glucocorticoids) and neurotransmitters that converge in modulating the noradrenergic system within the amygdala. Considerable evidence also indicates that amygdala activation influences memory by regulating consolidation in other brain regions. The findings suggest further that this memory-modulatory system may be involved in the formation of traumatic memories and posttraumatic stress disorder in human subjects.


Assuntos
Tonsila do Cerebelo/fisiologia , Memória/fisiologia , Animais , Aprendizagem da Esquiva/fisiologia , Humanos , Modelos Neurológicos , Neurotransmissores/fisiologia , Norepinefrina/metabolismo
14.
Behav Brain Res ; 134(1-2): 307-15, 2002 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-12191818

RESUMO

Recent evidence suggests that the basolateral amygdala (BLA) is involved in the expression of freezing behavior in rats. This study investigated the effects of unilateral phthalic acid (PA) lesions of the nucleus basalis magnocellularis (NBM) on fear-motivated behavior in response to a natural predator-stimulus. Such lesions preferentially disrupt the cholinergic projection to the BLA. Rats were placed in a chamber containing either real or fake cat hair, and the amount of time spent freezing and the number of contacts made with the stimulus were measured. Compared with Sham control rats, the PA NBM-lesioned rats displayed significantly less freezing in the presence of the cat hair. Both the Sham and lesioned rats made fewer contacts with the real than the fake cat hair. Pre-testing intra-BLA infusion of the direct muscarinic cholinergic agonist oxotremorine ipsilateral to the PA NBM-lesion attenuated the freezing deficit. The indirect non-specific cholinergic agonist physostigmine increased the time spent freezing in Sham rats, but did not attenuate the freezing deficit in the NBM-lesioned rats. Sham and NBM-lesioned rats given oxotremorine infusions made fewer contacts with either the real or the fake cat hair. The PA NBM-lesion did not affect open field activity. These findings indicate that muscarinic cholinergic activation in the BLA from the NBM influences fear-motivated freezing behavior.


Assuntos
Tonsila do Cerebelo/fisiologia , Comportamento Animal/fisiologia , Medo/fisiologia , Sistema Nervoso Parassimpático/fisiologia , Animais , Gatos , Agonistas Colinérgicos/farmacologia , Eletrochoque , Comportamento Exploratório/efeitos dos fármacos , Cabelo , Masculino , Neurônios Eferentes/fisiologia , Ratos , Ratos Sprague-Dawley , Ganho de Peso/efeitos dos fármacos
15.
Neurobiol Learn Mem ; 77(3): 372-88, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11991764

RESUMO

The basolateral amygdala (BLA) is extensively implicated in emotional learning and memory. The current study investigated the contribution of cholinergic afferents to the BLA from the nucleus basalis magnocellularis in influencing aversive learning and memory. Sprague-Dawley rats were given permanent unilateral phthalic acid (300 ng) lesions of the nucleus basalis magnocellularis and were chronically implanted with cannulas aimed at the ipsilateral BLA. Lesioned rats showed a pronounced inhibitory avoidance task retention deficit that was attenuated by acute posttraining infusions of the muscarinic cholinergic agonist oxotremorine (4 ng) or the indirect agonist physostigmine (1 microg) into the BLA. Continuous multiple-trial inhibitory avoidance training and testing revealed that lesioned rats have a mild acquisition deficit, requiring approximately 1 additional shock to reach the criterion, and a pronounced consolidation deficit as indicated by a shorter latency to enter the shock compartment on the retention test. Because lesioned rats did not differ from sham-operated controls in performance on a spatial water maze task or in shock sensitivity, it is not likely that the memory impairments produced by the phthalic acid lesions are due to any general sensory or motor deficits. These findings suggest that the dense cholinergic projection from the nucleus basalis magnocellularis to the BLA is involved in both the acquisition and the consolidation of the aversive inhibitory avoidance task.


Assuntos
Tonsila do Cerebelo/efeitos dos fármacos , Tonsila do Cerebelo/patologia , Núcleo Basal de Meynert/efeitos dos fármacos , Núcleo Basal de Meynert/patologia , Transtornos da Memória/induzido quimicamente , Ácidos Ftálicos/efeitos adversos , Animais , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Transtornos da Memória/diagnóstico , Ratos , Ratos Sprague-Dawley , Comportamento Espacial/efeitos dos fármacos
16.
Proc Natl Acad Sci U S A ; 99(4): 2315-9, 2002 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-11830635

RESUMO

Extensive evidence indicates that drugs and stress hormones act in the basolateral amygdala (BLA) to modulate memory consolidation. The BLA projects to the nucleus basalis magnocellularis (NBM), which sends broad cholinergic projections to the neocortex. NBM-cortex projections have been implicated in learning, memory storage, and plasticity. The current study investigated whether the cholinergic NBM-cortex projections are involved in BLA-mediated modulation of memory consolidation. Bilateral cholinergic cell lesions of the NBM were induced in rats with infusions of 192 IgG-saporin (0.1 microg/0.5 microl per side). Additionally, cannulae were implanted bilaterally in the BLA. One week after surgery, the rats were trained in an inhibitory avoidance task and, immediately after training, norepinephrine (0.3 microg, 1.0 microg, or 3.0 microg in 0.2 microl) or vehicle (PBS) was infused bilaterally into the BLA. Norepinephrine infusions produced a dose-dependent enhancement of 48-h retention (0.3 microg and 1.0 microg doses enhanced) in nonlesioned rats but did not affect retention in NBM-lesioned rats. Choline acetyltransferase assays of frontal and occipital cortices confirmed the NBM lesions. These findings indicate that cholinergic NBM-cortex projections are required for BLA-mediated modulation of memory consolidation.


Assuntos
Tonsila do Cerebelo/fisiologia , Gânglios da Base/fisiologia , Imunoglobulina G/metabolismo , Imunotoxinas , N-Glicosil Hidrolases , Norepinefrina/farmacologia , Proteínas de Plantas/farmacologia , Tonsila do Cerebelo/efeitos dos fármacos , Tonsila do Cerebelo/lesões , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Gânglios da Base/efeitos dos fármacos , Encéfalo/patologia , Colina O-Acetiltransferase/metabolismo , Relação Dose-Resposta a Droga , Masculino , Memória/efeitos dos fármacos , Modelos Anatômicos , Ratos , Ratos Sprague-Dawley , Proteínas Inativadoras de Ribossomos Tipo 1 , Saporinas
17.
Neurobiol Learn Mem ; 78(3): 539-52, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12559833

RESUMO

There is a strong consensus that the amygdala is involved in mediating influences of emotional arousal and stress on learning and memory. There is extensive evidence that the basolateral amygdala (BLA) is a critical locus of integration of neuromodulatory influences regulating the consolidation of several forms of memory. Many drug and stress hormone influences converge in activating the release of norepinephrine (NE) within the BLA. Evidence from studies using in vivo microdialysis and high-performance liquid chromatography indicates that increases in amygdala NE levels assessed following inhibitory avoidance training correlate highly with subsequent retention. Other evidence indicates that NE influences on memory consolidation require muscarinic cholinergic activation within the BLA provided by projections from the nucleus basalis magnocellularis (NB). Evidence from several experiments indicates that activation of the BLA plays an essential role in modulating memory consolidation processes involving other brain regions. These findings provide strong support for the hypothesis that the BLA plays a critical role in regulating the consolidation of lasting memories of significant experiences.


Assuntos
Tonsila do Cerebelo/anatomia & histologia , Tonsila do Cerebelo/fisiologia , Memória/fisiologia , Tonsila do Cerebelo/metabolismo , Núcleo Basal de Meynert/metabolismo , Fibras Colinérgicas/efeitos dos fármacos , Fibras Colinérgicas/metabolismo , Inibidores da Colinesterase/farmacologia , Humanos , Antagonistas Muscarínicos/farmacologia , Norepinefrina/metabolismo , Oxotremorina/farmacologia , Fisostigmina/farmacologia , Receptores Muscarínicos/efeitos dos fármacos , Receptores Muscarínicos/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...