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1.
Transplant Cell Ther ; 2024 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-38740138

RESUMEN

BACKGROUND: Allogeneic stem cell transplantation (alloSCT) offers curative potential for older patients with myeloid malignancies. We evaluated the efficacy and safety of alloSCT using post-transplantation cyclophosphamide (PTCy) in combination with a very short duration of immune suppression (IS) in this population. METHODS: We retrospectively analyzed 92 consecutive patients aged 65 years and older who underwent an alloSCT for myeloid malignancies between February 2018 and December 2022 at our institution. Data on patient characteristics, treatment modalities, and outcomes were collected. RESULTS: Ninety-two patients received an alloSCT with PTCy-based GVHD prophylaxis. The majority had minimal comorbidities and were diagnosed with acute myeloid leukemia (AML). Patients mostly received conditioning regimens with low to intermediate TCI scores. In 43% of patients, IS could be permanently stopped at day +90, resulting in a median time of IS of 2.93 months in high-risk patients. At a median follow-up of 21.3 months, the 1- and 2-year overall survival rates were 89% and 87%, respectively. Relapse-free survival rates were 88% and 84% at 1 and 2 years, respectively. The 1- and 2-year cumulative incidences of relapse were 8% and 13%, while transplant-related mortality (TRM) estimates were 9% at both time points. Acute GVHD grade 3-4 occurred in 7% within the first 180 days and severe chronic GVHD in 6% of patients. This all resulted in a 1- and 2-year graft versus host and relapse free survival (GRFS) of 74% and 70%, respectively. CONCLUSION: AlloSCT using PTCy in combination with a short duration of IS in older patients with myeloid malignancies demonstrates favorable survival outcomes due to low relapse rates and a low TRM. The low incidence of relapse and acceptable rates of graft-versus-host disease suggest the efficacy and safety of this approach. Further studies are warranted to validate these findings and optimize transplant strategies for older patients with myeloid malignancies.

4.
Eur J Cancer ; 63: 180-8, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27322917

RESUMEN

BACKGROUND: Metastatic testicular cancer (TC) can be cured with bleomycin, etoposide and cisplatin (BEP) chemotherapy. This comes at the price of an increased cardiovascular disease risk, not only years afterwards, but also during and shortly after chemotherapy. To prevent cardiovascular events, high-risk patients should be identified. The aim of this study was to assess BEP-chemotherapy induced vascular damage and to find risk factors for early vascular events. PATIENTS AND METHODS: A prospective cohort study was performed in (B)EP treated TC patients. Development of venous and arterial vascular events was assessed. Vascular damage markers (von Willebrand factor [vWF], coagulation factor VIII [FVIII], intima media thickness [IMT]) and cardiovascular risk factors were assessed before and until 1 year after chemotherapy. Before start of chemotherapy a vascular fingerprint was estimated. Presence of ≥3 risk factors was defined as high-risk vascular fingerprint: body mass index >25 kg/m(2), current smoking, blood pressure >140/90 mm Hg, total cholesterol >5.1 and/or low-density lipoprotein >2.5 mmol/L or glucose ≥7 mmol/L. RESULTS: Seventy-three patients were included. Eight (11%) developed vascular events (four arterial events, four pulmonary embolisms). vWF and FVIII increased during chemotherapy, especially in patients with vascular events. Sixteen patients (22%) had a high-risk vascular fingerprint before start of chemotherapy. These patients had arterial events more often (3/16 [19%] versus 1/57 [2%]; p = 0.031) and higher vWF levels and IMT. CONCLUSIONS: Endothelial activation and upregulation of procoagulant activity seem important mechanisms involved in early (B)EP-chemotherapy-induced vascular events. Before chemotherapy, a quarter already had cardiovascular risk factors. A vascular fingerprint could identify patients at risk for arterial events. This vascular fingerprint, when validated, can be used as a tool to select patients who may benefit from preventive strategies.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Enfermedades Cardiovasculares/diagnóstico , Neoplasias Testiculares/tratamiento farmacológico , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Biomarcadores/análisis , Bleomicina/administración & dosificación , Enfermedades Cardiovasculares/inducido químicamente , Grosor Intima-Media Carotídeo , Cisplatino/administración & dosificación , Etopósido/administración & dosificación , Factor VIII/análisis , Productos Finales de Glicación Avanzada/análisis , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Neoplasias Testiculares/complicaciones , Adulto Joven , Factor de von Willebrand/análisis
6.
J Neurophysiol ; 113(3): 925-36, 2015 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-25392174

RESUMEN

Changes in synchronized neuronal oscillatory activity are reported in both cortex and basal ganglia of Parkinson's disease patients. The origin of these changes, in particular their relationship with the progressive nigrostriatal dopaminergic denervation, is unknown. Therefore, in the present study we studied interregional neuronal synchronization in motor cortex and basal ganglia during the development of dopaminergic degeneration induced by a unilateral infusion of 6-hydroxydopamine (6-OHDA) into the rat medial forebrain bundle. We performed serial local field potential recordings bilaterally in the motor cortex and the subthalamic nucleus of the lesioned hemisphere prior to, during, and after development of the nigrostriatal dopaminergic cell loss. We obtained signal from freely moving rats in both resting and walking conditions, and we computed local spectral power, interregional synchronization (using phase lag index), and directionality (using Granger causality). After neurotoxin injection the first change in phase lag index was an increment in cortico-cortical synchronization. We observed increased bidirectional Granger causality in the beta frequency band between cortex and subthalamic nucleus within the lesioned hemisphere. In the walking condition, the 6-OHDA lesion-induced changes in synchronization resembled that of the resting state, whereas the changes in Granger causality were less pronounced after the lesion. Considering the relatively preserved connectivity pattern of the cortex contralateral to the lesioned side and the early emergence of increased cortico-cortical synchronization during development of the 6-OHDA lesion, we suggest a putative compensatory role of cortico-cortical coupling.


Asunto(s)
Sincronización Cortical , Corteza Motora/fisiología , Enfermedad de Parkinson Secundaria/fisiopatología , Animales , Ganglios Basales/fisiología , Ritmo beta , Locomoción , Masculino , Oxidopamina/toxicidad , Enfermedad de Parkinson Secundaria/etiología , Ratas , Ratas Wistar , Descanso
7.
J Thromb Haemost ; 12(9): 1488-93, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24954113

RESUMEN

BACKGROUND: Bleeding disorders have been recognized as important etiologic or contributory factors in women with heavy menstrual bleeding. Fibrinolysis in the endometrium plays a role in heavy menstrual bleeding. It is unknown whether increased systemic fibrinolysis might also increase the risk of heavy menstrual bleeding. OBJECTIVE: To investigate fibrinolytic parameters, including clot lysis time, in women with heavy menstrual bleeding. METHODS: We included 102 patients referred for heavy menstrual bleeding (Pictorial Bleeding Assessment Chart score of > 100) in our cohort. Patients and controls (28 healthy volunteers without heavy menstrual bleeding) underwent hemostatic testing in the first week after menstruation. For 79 patients and all controls, fibrinolytic parameters (thrombin-activatable fibrinolysis inhibitor activity, and plasminogen activator inhibitor-1, tissue-type plasminogen activator and plasmin inhibitor levels) and clot lysis time were available. RESULTS: Fibrinolytic parameters were similar between patients and controls, except for thrombin-activatable fibrinolysis inhibitor (89.4% vs. 82.5%) and plasmin inhibitor (106% vs. 96%), the levels of which which were significantly higher in patients. In women with menorrhagia without gynecologic abnormalities, we found lower thrombin-activatable fibrinolysis inhibitor and plasminogen activator inhibitor-1 levels than in women with gynecologic abnormalities (thrombin-activatable fibrinolysis inhibitor, 85.4% vs. 94.8%; plasminogen activator inhibitor-1, 16.0 µg L(-1) vs. 24.5 µg L(-1) ). CONCLUSION: Systemic fibrinolytic capacity is not increased in women with heavy menstrual bleeding. Overall, levels of the fibrinolytic inhibitors thrombin-activatable fibrinolysis inhibitor and plasmin inhibitor were even higher in patients than in controls. However, in a subgroup of women without gynecologic abnormalities, relatively lower levels of inhibitors may contribute to the heavy menstrual bleeding.


Asunto(s)
Carboxipeptidasa B2/metabolismo , Endometrio/metabolismo , Fibrinólisis , Menorragia/complicaciones , Inhibidor 1 de Activador Plasminogénico/metabolismo , Adulto , Coagulación Sanguínea , Pruebas de Coagulación Sanguínea , Índice de Masa Corporal , Estudios de Casos y Controles , Endometrio/patología , Femenino , Voluntarios Sanos , Hemorragia/complicaciones , Hemostasis , Humanos , Menstruación , Persona de Mediana Edad
8.
Int J Obes (Lond) ; 37(7): 1012-9, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23069665

RESUMEN

BACKGROUND: Cues that are associated with the availability of food are known to trigger food anticipatory activity (FAA). This activity is expressed as increased locomotor activity and enables an animal to prepare for maximal utilization of nutritional resources. Although the exact neural network that mediates FAA is still unknown, several studies have revealed that the medial hypothalamus is involved. Interestingly, this area is responsive to the anorexigenic hormone leptin and the orexigenic hormone ghrelin that have been shown to modulate FAA. However, how FAA is regulated by neuronal activity and how leptin and ghrelin modulate this activity is still poorly understood. OBJECTIVE: We aimed to examine how the total neuronal population and individual neurons in the medial hypothalamus respond to cue-signaled food availability in awake, behaving rats. In addition, ghrelin and leptin were injected to investigate whether these hormones could have a modulatory role in the regulation of FAA. DESIGN: Using in vivo electrophysiology, neuronal activity was recorded in the medial hypothalamus in freely moving rats kept on a random feeding schedule, in which a light cue signaled upcoming food delivery. Ghrelin and leptin were administered systemically following the behavioral paradigm. RESULTS: The food-predictive cue induced FAA as well as a significant increase in neural activity on a population level. More importantly, a sub-population of medial hypothalamic neurons displayed highly correlated identical responses to both ghrelin and FAA, suggesting that these neurons are part of the network that regulates FAA. CONCLUSION: This study reveals a role for ghrelin, but not leptin, signaling within medial hypothalamus in FAA on both a population level and in single cells, identifying a subset of neurons onto which cue information and ghrelin signaling converge, possibly to drive FAA.


Asunto(s)
Conducta Alimentaria/fisiología , Ghrelina/metabolismo , Leptina/metabolismo , Actividad Motora/fisiología , Animales , Anticipación Psicológica/efectos de los fármacos , Conducta Animal , Señales (Psicología) , Conducta Alimentaria/efectos de los fármacos , Ghrelina/farmacología , Hipotálamo/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Leptina/farmacología , Masculino , Actividad Motora/efectos de los fármacos , Neuropéptido Y/metabolismo , Ratas , Ratas Wistar
10.
Allergy ; 67(5): 683-90, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22435702

RESUMEN

BACKGROUND: Risk indicators of indolent systemic mastocytosis (ISM) in adults with clinical suspicion of ISM without accompanying skin lesions [urticaria pigmentosa (UP)] are lacking. This study aimed at creating a decision tree using clinical characteristics, serum tryptase, and the urinary histamine metabolites methylimidazole acetic acid (MIMA) and methylhistamine (MH) to select patients for bone marrow investigations to diagnose ISM. METHODS: Retrospective data analysis of all adults, in whom bone marrow investigations were performed to diagnose ISM, was carried out. RESULTS: In total, 142 patients were included. SM was absent in all 44 patients with tryptase <10 µg/l, in 45 of 98 (46%) patients with tryptase ≥10 µg/l and in 18 of 52 patients (35%) with tryptase >20 µg/l. Above 43 µg/l, all patients had ISM (n = 11). Male gender, insect venom anaphylaxis as presenting symptom, tryptase, MIMA, and MH were independent ISM predictors. If tryptase was ≥10 µg/l, the diagnostic accuracy of MIMA and MH was high (areas under the ROC curve 0.92). CONCLUSIONS: In suspected patients without UP, the ISM risk is very low (if present at all) if tryptase is <10 µg/l. If tryptase is ≥10 µg/l, this risk depends on MIMA and MH, being low if these are normal, but high if these are elevated. Male gender and insect venom anaphylaxis are additional risk indicators. We recommend refraining from bone marrow examinations in suspected patients without UP if tryptase is <10 µg/l. Our results question the reliability of the minor diagnostic World Health Organization criterion of tryptase >20 µg/l.


Asunto(s)
Imidazoles/orina , Mastocitosis Sistémica/complicaciones , Mastocitosis Sistémica/diagnóstico , Metilhistaminas/orina , Triptasas/sangre , Urticaria Pigmentosa/complicaciones , Adulto , Médula Ósea/metabolismo , Médula Ósea/patología , Femenino , Histamina/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Curva ROC , Estudios Retrospectivos , Riesgo
11.
Br J Dermatol ; 166(2): 405-12, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21967609

RESUMEN

BACKGROUND: Rituximab, an anti-CD20 antibody, was shown in open series studies to be effective in treating pemphigus at a dose of 4 × 375 mgm(-2) as approved for B-cell malignancies. OBJECTIVES: We investigated whether a lower dose of rituximab is also effective for pemphigus. METHODS: Patients with pemphigus were treated with a single course of two infusions of rituximab (500 mg each) at an interval of 2 weeks. Clinical consensus late end points, B-cell number, desmoglein 1 and desmoglein 3 indices were monitored. RESULTS: We enrolled 15 patients in the study: three with pemphigus foliaceus (PF) and 12 with pemphigus vulgaris (PV). The follow-up was 32-152 weeks (median 94). All 15 patients responded to therapy. Eight patients achieved complete remission in a median period of 5 weeks (four on minimal therapy, four off therapy). Seven patients achieved partial remission in a median period of 34·5 weeks (five on minimal therapy, two off therapy). Relapses (40%) were seen between 53 and 103 weeks (median 97) after start of therapy. B-cell numbers dropped to <1% after first infusion, and remained undetectable in patients with sustained remission. The antidesmoglein 1 index correlated well with the clinical severity in PF, but this was less obvious in PV. CONCLUSIONS: A low dose of rituximab is an effective and safe treatment for pemphigus. Relapses may occur, mostly at the end of the second year. Cost-effectiveness studies with a long follow-up are required to determine the proper dosage of this expensive drug in pemphigus.


Asunto(s)
Anticuerpos Monoclonales de Origen Murino/administración & dosificación , Fármacos Dermatológicos/administración & dosificación , Factores Inmunológicos/administración & dosificación , Pénfigo/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos/metabolismo , Anticuerpos Monoclonales de Origen Murino/efectos adversos , Antígenos CD20/metabolismo , Linfocitos B/efectos de los fármacos , Fármacos Dermatológicos/efectos adversos , Desmogleína 1/inmunología , Desmogleína 3/inmunología , Femenino , Humanos , Factores Inmunológicos/efectos adversos , Masculino , Persona de Mediana Edad , Uso Fuera de lo Indicado , Estudios Prospectivos , Recurrencia , Rituximab , Resultado del Tratamiento
12.
J Thromb Haemost ; 9(12): 2416-23, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21972946

RESUMEN

BACKGROUND: Overt proteinuria is a strong risk factor for thromboembolism, owing to changes in the levels of various coagulation proteins and urinary antithrombin loss. The described coagulation disturbances in these patients are based on outdated studies conducted primarily in the 1970s and 1980s. Whether these coagulation disturbances resolve with antiproteinuric therapy has yet to be studied. METHODS: A total of 32 patients with overt proteinuria (median, 3.7 g day(-1) ; interquartile range, 1.5-5.6) were enrolled in this intervention crossover trial designed to assess optimal antiproteinuric therapy with sodium restriction, losartan, and diuretics. Levels of various procoagulant and anticoagulant proteins, and parameters of two thrombin generation assays (calibrated automated thrombogram [CAT] and prothrombin fragment 1 + 2) were compared between the placebo period and the maximum antiproteinuric treatment period. As a secondary analysis, coagulation measurements of the placebo period in these patients were compared with those of 32 age-matched and sex-matched healthy controls. RESULTS: Median proteinuria was significantly lower during the maximum treatment period (median, 0.9 g day(-1) ; interquartile range, 0.6-1.4; P < 0.001) than during the placebo period. Similarly, levels of various liver-synthesized procoagulant and anticoagulant proteins, activated protein C resistance and prothrombin fragment 1 + 2 levels were significantly lower during the maximum treatment period than during the placebo period. However, von Willebrand factor and factor VIII levels were similar. On the basis of the higher levels of procoagulant proteins (fibrinogen, FV, FVIII, and von Willebrand factor) and both thrombin generation assays, patients were substantially more prothrombotic than healthy controls (P < 0.004). CONCLUSIONS: Antiproteinuric therapy ameliorates the prothrombotic state. Proteinuric patients are in a more prothrombotic state than healthy controls.


Asunto(s)
Losartán/uso terapéutico , Proteinuria/tratamiento farmacológico , Protrombina/metabolismo , Trombosis/complicaciones , Adulto , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Placebos , Proteinuria/complicaciones
13.
Allergy ; 66(2): 229-37, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21208217

RESUMEN

BACKGROUND: Mastocytosis is an uncommon disease resulting from proliferation of abnormal mast cells infiltrating skin, bone marrow, liver, and other tissues. The aim of this study was to find differences in gene expression in peripheral blood cells of patients with indolent systemic mastocytosis compared to healthy controls. The second aim was to define a specific gene expression profile in patients with mastocytosis. METHODS: Twenty-two patients with indolent systemic mastocytosis and 43 healthy controls were studied. Whole genome gene expression analysis was performed on RNA samples isolated from the peripheral blood. For amplification and labelling of the RNA, the Illumina TotalPrep 96 RNA Amplification Kit was used. Human HT-12_V3_expression arrays were processed. Data analysis was performed using GeneSpring, Genecodis, and Transcriptional System Regulators. RESULTS: Comparison of gene expression between patients and controls revealed a significant difference (P < 0.05 corrected for multiple testing) and the fold change difference >2 in gene expression in 2303 of the 48.794 analysed transcripts. Functional annotation indicated that the main pathways in which the differently expressed genes were involved are ubiquitin-mediated proteolysis, MAPK signalling pathway, pathways in cancer, and Jak-STAT signalling. The expression distributions for both groups did not overlap at all, indicating that many genes are highly differentially expressed in both groups. CONCLUSION: We were able to find abnormalities in gene expression in peripheral blood cells of patients with indolent systemic mastocytosis and to construct a gene expression profile which may be useful in clinical practice to predict the presence of mastocytosis and in further research of novel drugs.


Asunto(s)
Perfilación de la Expresión Génica , Mastocitosis Sistémica/genética , Transducción de Señal/genética , Transcripción Genética , Adulto , Anciano , Células Sanguíneas/metabolismo , Estudios de Casos y Controles , Femenino , Regulación de la Expresión Génica , Humanos , Masculino , Mastocitosis Sistémica/sangre , Persona de Mediana Edad , ARN Mensajero/análisis
14.
Clin Microbiol Infect ; 17(5): 747-9, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21175551

RESUMEN

Cytomegalovirus is associated with hypercoagulability, and is reported to increase the risk of venous thrombosis in human immunodeficiency virus (HIV)-infected patients. Progression to AIDS, however, is also associated with hypercoagulability and venous thrombosis, and may result in more comorbidities, such as reactivation of cytomegalovirus. It is therefore unknown whether active cytomegalovirus in HIV infection results in a procoagulant state or whether hypercoagulability is the result of HIV infection itself. In this cross-sectional study of 104 consecutive HIV-infected patients, active cytomegalovirus infection was associated with hypercoagulability independently of stage of HIV disease. This finding may deserve attention in preventative recommendations for use of thromboprophylaxis in HIV-infected patients.


Asunto(s)
Infecciones por Citomegalovirus/sangre , Citomegalovirus , Infecciones por VIH/sangre , Trombofilia/sangre , Tromboplastina/análisis , Infecciones Oportunistas Relacionadas con el SIDA/complicaciones , Infecciones Oportunistas Relacionadas con el SIDA/virología , Adulto , Anciano , Linfocitos T CD4-Positivos , Estudios Transversales , Infecciones por Citomegalovirus/complicaciones , Infecciones por Citomegalovirus/virología , Femenino , Infecciones por VIH/complicaciones , Infecciones por VIH/virología , Humanos , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Proteína S/análisis , Trombosis
16.
J Thromb Haemost ; 8(6): 1193-200, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20230415

RESUMEN

BACKGROUND: Absolute risks of venous thromboembolism (VTE) in protein S-, protein C-, or antithrombin-deficient subjects are mainly based on retrospective data. Screening asymptomatic relatives of these patients is disputed, though studies addressing this issue have yet to be conducted. METHODS: We prospectively followed 382 relatives of 84 probands. Participants were assessed for other thrombophilic defects and occurrence of exogenous risk factors (i.e. surgery/trauma/immobilization, malignancies, use of systemic estrogens, and pregnancy/puerperium). After screening, deficient subjects were advised to use thromboprophylaxis during exogenous risk factors; use of oral contraceptives was discouraged. RESULTS: Overall annual incidence of VTE was 1.53% (95% CI, 1.00-2.34) in deficient vs. 0.29% (0.13-0.64) in non-deficient relatives; adjusted hazard ratio, 7.0 (95% CI, 2.7-18.0). Annual incidence of unprovoked VTE was 0.95% in deficient vs. 0.05% in non-deficient subjects; age-adjusted hazard ratio, 22.3 (P = 0.003). In contrast, annual incidence of provoked VTE was 0.58% vs. 0.24%; age-adjusted hazard ratio, 2.8 (P = 0.08). Fifty-five (37%) deficient and 80 (34%) non-deficient subjects experienced 91 and 143 exogenous risk factors, respectively, during which six vs. five VTEs (6.6% vs 3.5% per risk-period) occurred, despite the higher compliance with recommended thromboprophylaxis use in deficient (51%) vs. non-deficient (22%) subjects. In deficient subjects all provoked VTEs occurred when thromboprophylaxis was not used. CONCLUSIONS: Protein S, protein C or antithrombin deficiencies confer high absolute risk of VTE. Screening and subsequent augmentation of thromboprophylaxis use may result in reduction of provoked VTE, whereas risk of unprovoked VTE could not be affected by screening.


Asunto(s)
Deficiencia de Proteína C/genética , Deficiencia de Proteína S/genética , Trombofilia/genética , Tromboembolia Venosa/epidemiología , Humanos , Estudios Prospectivos , Factores de Riesgo , Tromboembolia Venosa/diagnóstico
18.
J Pharmacol Exp Ther ; 323(1): 61-9, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17626795

RESUMEN

To be able to address the question how neurotransmitters or pharmacological agents influence activity of neuronal populations in freely moving animals, the combidrive was developed. The combidrive combines an array of 12 tetrodes to perform ensemble recordings with a moveable and replaceable microdialysis probe to locally administer pharmacological agents. In this study, the effects of cumulative concentrations of tetrodotoxin, lidocaine, and muscimol on neuronal firing activity in the prefrontal cortex were examined and compared. These drugs are widely used in behavioral studies to transiently inactivate brain areas, but little is known about their effects on ensemble activity and the possible differences between them. The results show that the combidrive allows ensemble recordings simultaneously with reverse microdialysis in freely moving rats for periods at least up to 2 wk. All drugs reduced neuronal firing in a concentration dependent manner, but they differed in the extent to which firing activity of the population was decreased and the in speed and extent of recovery. At the highest concentration used, both muscimol and tetrodotoxin (TTX) caused an almost complete reduction of firing activity. Lidocaine showed the fastest recovery, but it resulted in a smaller reduction of firing activity of the population. From these results, it can be concluded that whenever during a behavioral experiment a longer lasting, reversible inactivation is required, muscimol is the drug of choice, because it inactivates neurons to a similar degree as TTX, but it does not, in contrast to TTX, affect fibers of passage. For a short-lasting but partial inactivation, lidocaine would be most suitable.


Asunto(s)
Lidocaína , Microdiálisis/métodos , Muscimol , Neuronas/fisiología , Tetrodotoxina , Potenciales de Acción/efectos de los fármacos , Animales , Relación Dosis-Respuesta a Droga , Lidocaína/administración & dosificación , Lidocaína/farmacología , Masculino , Microdiálisis/instrumentación , Modelos Animales , Muscimol/administración & dosificación , Muscimol/farmacología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neurotransmisores/metabolismo , Neurotransmisores/fisiología , Ratas , Ratas Wistar , Tetrodotoxina/administración & dosificación , Tetrodotoxina/farmacología
19.
Exp Brain Res ; 163(1): 32-43, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15654593

RESUMEN

To study how hippocampal output signals conveying spatial and other contextual information might be integrated in the nucleus accumbens, tonically active accumbens neurons were recorded in three unrestrained rats as they performed spatial orientation tasks on an elevated round rotatable platform with four identical reward boxes symmetrically placed around the edge. The partially water-deprived rats were required to shuttle either between the pair of reward boxes indicated by beacon cues (lights in the boxes) or between the pair of boxes occupying particular locations in relation to environmental landmark cues. In 43/82 neurons, behaviorally correlated phasic modulations in discharge activity occurred, primarily prior to or after water was provided at the reward boxes. Twenty-two had inhibitory modulation, 12 excitatory, and nine were mixed excitatory and inhibitory. Although tonically active neurons (TANs) have rarely been reported in the rodent, the inhibitory and mixed responses correspond to previously reports in the macaque accumbens of tonically active neurons with activity correlated with reward delivery and, following conditioning, to sensory stimuli associated with rewards. Eighteen of the 43 tonically active accumbens neurons showed spatial selectivity, i.e., behaviorally correlated increases or decreases in firing rate were of different magnitudes at the respective reward boxes. This is the first demonstration that the configuration of environmental sensory cues associated with reward sites are also an effective stimulus for these neurons and that different neurons are selective for different places. These results are consistent with a role for the nucleus accumbens in the initiation of goal-directed displacement behaviors.


Asunto(s)
Neuronas/fisiología , Núcleo Accumbens/fisiología , Recompensa , Percepción Espacial/fisiología , Animales , Conducta Animal , Condicionamiento Psicológico , Electrofisiología , Objetivos , Masculino , Núcleo Accumbens/citología , Ratas , Ratas Long-Evans , Privación de Agua
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