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1.
Prim Care Diabetes ; 17(6): 632-638, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37891057

RESUMO

AIMS: To study the association between risk factors and chronic kidney disease (CKD), and characterize medication use in Finnish primary care type 2 diabetes (T2D) patients. METHODS: Data on clinical characteristics, laboratory measurements, and medications were collected from medical records. The primary outcome measure was notable CKD (stage 3-5, eGFR <60 ml/min/1.73 m2) and/or increased albuminuria. The explanatory variables were individual risk factors and risk factor groups based on their number (0-2, 3-4, 5-6, >7). Spearman's rank correlation coefficient and risk ratio analysis were used to analyze the association between the number of risk factors and CKD stage, and between the number of risk factors and notable CKD, respectively. RESULTS: Altogether, 1335 patients with T2D in 60 Finnish primary care centers were recruited for this cross-sectional study. Three-quarters of T2D patients had 3 risk factors and 36% had ≥ 5 risk factors. Compared to patients with 0-2 risk factors, patients with 3-4, 5-6, and ≥ 7 risk factors had a 5.5-fold, 9.9-fold, and 15.9-fold risk of notable CKD (p < 0.001), respectively. Heart failure was most strongly associated with notable CKD (risk ratio, 3.7; p < 0.001). CONCLUSIONS: Number of risk factors was strongly associated with advanced-stage CKD.


Assuntos
Diabetes Mellitus Tipo 2 , Insuficiência Cardíaca , Insuficiência Renal Crônica , Humanos , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/complicações , Estudos Transversais , Taxa de Filtração Glomerular , Fatores de Risco , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/epidemiologia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/etiologia
2.
Acta Derm Venereol ; 103: adv00886, 2023 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-36892511

RESUMO

Therapeutic options for psoriasis vulgaris have changed during recent decades with the introduction of biologics. Few nationwide studies are available on psoriasis treatment patterns, and those from Finland predate the use of biologics. The aim of this retrospective, population-based registry study was to identify patients with psoriasis vulgaris and their treatment patterns in the secondary care setting in Finland. The study cohort included 41,456 adults with a diagnosis of psoriasis vulgaris in the public secondary healthcare setting from 2012 through 2018. Data on comorbidities, pharmacotherapy, and phototherapy were collected from nationwide healthcare and drug registries. Patients in the cohort had a wide range of comorbidities, with 14.9% having psoriatic arthritis. Treatment was based largely on topical and conventional systemic medications. Conventional medications were used by 28.9% of patients, and methotrexate was the most common option (20.9%). Biologics were used by 7.3% of patients, mostly as second- and third-line treatment. The use of conventional systemic medications, topical treatments, and phototherapy decreased after the initiation of biologics. This study of psoriasis vulgaris in Finland provides a framework for the development of future care practices.


Assuntos
Produtos Biológicos , Psoríase , Adulto , Humanos , Finlândia/epidemiologia , Estudos Retrospectivos , Psoríase/diagnóstico , Psoríase/tratamento farmacológico , Psoríase/epidemiologia , Sistema de Registros , Produtos Biológicos/efeitos adversos
3.
J Mark Access Health Policy ; 11(1): 2166313, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36684852

RESUMO

BACKGROUND: The increasing prevalence of obesity imposes a significant cost burden on individuals and societies worldwide. OBJECTIVE: In this nationally representative study, the association between body mass index (BMI) groups and the number of metabolic comorbidities (MetC) with total direct costs was investigated in the Finnish population. STUDY DESIGN, SETTING, AND PARTICIPANTS: The study cohort included 5,587 adults with BMI ≥18.5 kg/m2 who participated in the cross-sectional FinHealth 2017 health examination survey conducted by the Finnish Institute for Health and Welfare. Data on healthcare resource utilization (HCRU) and drug purchases were collected from national healthcare and drug registers. MAIN OUTCOME MEASURE: The primary outcome was total direct costs (costs of primary and secondary HCRU and prescription medications). RESULTS: Class I (BMI 30.0-34.9 kg/m2) and class II - III (BMI ≥35.0 kg/m2) obesity were associated with 43% and 40% higher age- and sex-adjusted direct costs, respectively, compared with normal weight, mainly driven by a steeply increased comorbidity in the higher BMI groups. In all BMI groups combined, individuals with ≥2 MetCs comprised 39% of the total study population and 60% of the total costs. CONCLUSION: To manage the cost burden of obesity, treatment should be given equal consideration as other chronic diseases, and BMIs ≥30.0 kg/m2 should be considered in treatment decisions.

4.
Eur J Health Econ ; 24(9): 1421-1428, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36449133

RESUMO

OBJECTIVES: To evaluate the association between health and social care costs and early start of anti-dementia medication in a nationwide cohort of Finnish Alzheimer's disease (AD) patients. METHODS: The cohort included 7454 Finnish AD patients who had their first AD diagnosis in 2012 and lived at home at the time of diagnosis. Data were collected retrospectively from the Finnish national health and social care registers. The primary outcome was 2-year cumulative direct costs after the incident AD diagnosis. The exploratory variable was early anti-dementia medication start (anti-dementia medication started within 3 months of the incident AD diagnosis). Sociodemographic variables, admission to 24-h care and care intensity level, as well as comorbidities were considered as adjusting variables. RESULTS: Of all patients, 88.9% started AD medication within 3 months of diagnosis. The 2-year cumulative costs were €30,787 and €40,484 per patient for early and late starters, respectively. When adjusted for possible confounders, early start of anti-dementia medication was associated with 26.5% lower 2-year cumulative costs compared to late starters (relative cost 0.735; p < 0.001). CONCLUSIONS: Early diagnosis and start of anti-dementia medication is important for managing the costs of increasing number of AD patients.


Assuntos
Doença de Alzheimer , Humanos , Doença de Alzheimer/tratamento farmacológico , Estudos Retrospectivos , Finlândia , Hospitalização , Comorbidade , Custos de Cuidados de Saúde
5.
Eur J Health Econ ; 24(5): 769-781, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36063259

RESUMO

AIM: To characterize healthcare resource (HCRU) and medication use and associated costs in individuals with obesity compared with individuals with normal weight or overweight in a population-based cohort of Finnish adults. The association between metabolic state and direct costs was also assessed. METHODS: The study cohort included 5587 randomly selected individuals who participated in the national FinHealth 2017 health examination survey. Data on healthcare visits and hospital stays, including diagnoses (ICD-10), and purchases and costs of prescription medicines were collected from the nationwide registers by the Finnish Institute for Health and Welfare and Social Insurance Institution of Finland. The healthcare costs were calculated based on standard unit costs reported by the Finnish Institute for Health and Welfare. RESULTS: The total annual direct costs were €2665 (SD €5673) and €1799 (SD €3874) per person with obesity and with normal weight or overweight, respectively. Obesity was associated with significantly increased total direct (age- and sex-adjusted cost rate ratio, RR, 1.356; p < 0.001), HCRU-related (1.273; p = 0.002), and medication (1.669; p < 0.001) costs. A vast majority (90%) of individuals with obesity were classified as metabolically unhealthy based on clinical measurements. The metabolically unhealthy state was associated with increased costs in individuals with obesity but not in individuals with normal weight or overweight. CONCLUSION: Obesity is associated with a significant and complex direct cost burden to society, arising primarily from increased comorbidity. Metabolically healthy obesity is uncommon and obesity prevention and timely treatment should be of high priority to tackle the increasing burden of obesity.


Assuntos
Obesidade , Sobrepeso , Adulto , Humanos , Sobrepeso/complicações , Sobrepeso/metabolismo , Finlândia/epidemiologia , Índice de Massa Corporal , Obesidade/epidemiologia , Custos de Cuidados de Saúde
6.
Prim Care Diabetes ; 16(1): 135-141, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34972659

RESUMO

AIMS: To characterize clinical profiles, prevalence of chronic kidney disease (CKD), and treatment patterns in type 2 diabetes (T2D) and heart failure (HF) patients in Finnish primary care. METHODS: A total of 1385 patients (1196 with T2D, 50 with HF, and 139 with T2D and HF) in 60 Finnish primary care centers were recruited to this cross-sectional study. Data on demographic and clinical characteristics, laboratory measurements, and medications were collected retrospectively from medical records. T2D patients were classified according to their risk of cardiovascular (CV) events as very high-risk (62%) and other patients (38%). RESULTS: Of the T2D patients, 10% (139/1335) had a diagnosis of HF and 42% (457/1090) had stage 3-5 CKD and/or albuminuria based on laboratory measurement. Of the HF patients, 74% (139/189) had T2D and 78% (114/146) had stage 3-5 CKD and/or albuminuria. Metformin was the most frequently used medication in both very high-risk patients (74%) and other patients (86%). SGLT2 inhibitors and/or GLP-1 analogues were used by 37% of very high-risk patients compared to 42% in other patients. CONCLUSIONS: The majority of T2D patients in Finnish primary care are at very high risk of cardiovascular events. However, the implementation of treatments with proven cardioprotective effects in very high-risk patients is currently suboptimal.


Assuntos
Diabetes Mellitus Tipo 2 , Insuficiência Cardíaca , Insuficiência Renal Crônica , Estudos Transversais , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/epidemiologia , Finlândia/epidemiologia , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Atenção Primária à Saúde , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/epidemiologia , Estudos Retrospectivos
7.
Qual Life Res ; 31(2): 413-423, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34533758

RESUMO

PURPOSE: The impact of obesity on quality of life (QoL) and working ability vary in different dimensions. This study investigated the association of obesity with QoL and working ability in Finnish adults. Comorbidities as associative factors were also characterised. METHODS: This cross-sectional study included 4956 randomly selected adults. QoL (EUROHIS-QOL 8 total score and individual components), perceived physical and psychological working ability, and sick leave days were analysed in different body mass index (BMI) groups. Regression models were used to study the role of comorbidities as associative factors. RESULTS: EUROHIS-QOL 8 total score was significantly lower in BMI group 25.0-29.9 kg/m2 (4.01; 95% confidence interval 3.97-4.05), BMI 30.0-34.9 kg/m2 (3.85; 3.79-3.91), BMI 35.0-39.9 kg/m2 (3.75; 3.66-3.85), and BMI ≥ 40.0 kg/m2 (3.73; 3.46-4.00) compared to individuals with normal (18.5-24.9 kg/m2) BMI (4.08; 4.04-4.12). Individuals with obesity (BMI ≥ 30.0 kg/m2) rated their QoL lower than individuals with normal BMI in seven of the eight EUROHIS-QOL 8 components. A lesser proportion of individuals (53-73%) with obesity rated their physical working ability as very or fairly good compared to individuals with normal BMI (90%, p values < 0.001). The psychological working ability was rated as very or fairly good by 71-75% of individuals with obesity compared to 85% of individuals with normal BMI (p = 0.008 and p = 0.001 in individuals with BMI 30.0-34.9 and BMI 35.0-39.9 kg/m2, respectively). CONCLUSIONS: Obesity was negatively associated with both physical and psychological components of QoL, even after accounting for obesity-related comorbidities. Obesity treatment can benefit from a holistic approach that considers these multifaceted associations.


Assuntos
Obesidade , Qualidade de Vida , Adulto , Índice de Massa Corporal , Estudos Transversais , Finlândia/epidemiologia , Humanos , Obesidade/epidemiologia , Qualidade de Vida/psicologia
8.
J Alzheimers Dis ; 81(3): 1103-1115, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33843673

RESUMO

BACKGROUND: Dementia is one of the strongest predictors of admission to a 24-hour care facility among older people, and 24-hour care is the major cost of Alzheimer's disease (AD). OBJECTIVE: The aim of this study was to evaluate the association of early start of anti-dementia medication and other predisposing factors with 2-year risk of transition to 24-hour care in the nationwide cohort of Finnish AD patients. METHODS: This was a retrospective, non-interventional study based on individual-level data from Finnish national health and social care registers. The incident cohort included 7,454 AD patients (ICD-10, G30) comprised of two subgroups: those living unassisted at home (n = 5,002), and those receiving professional home care (n = 2,452). The primary outcome was admission to a 24-hour care facility. Exploratory variables were early versus late anti-dementia medication start, sociodemographic variables, care intensity level, and comorbidities. RESULTS: Early anti-dementia medication reduced the risk of admission to 24-hour care both in patients living unassisted at home, with a hazard ratio (HR) of 0.58 (p < 0.001), and those receiving professional home care (HR, 0.84; p = 0.039). Being unmarried (HR, 1.69; p < 0.001), having an informal caregiver (HR, 1.69; p = 0.003), or having a diagnosis of additional neurological disorder (HR, 1.68; p = 0.006) or hip fracture (HR, 1.61; p = 0.004) were associated with higher risk of admission to 24-hour care in patients living unassisted at home. CONCLUSION: To support living at home, early start of anti-dementia medication should be a high priority in newly diagnosed AD patients.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/uso terapêutico , Nootrópicos/uso terapêutico , Casas de Saúde , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Donepezila/uso terapêutico , Feminino , Finlândia , Galantamina/uso terapêutico , Humanos , Masculino , Memantina/uso terapêutico , Estudos Retrospectivos , Rivastigmina/uso terapêutico , Tempo para o Tratamento
9.
Neuropharmacology ; 195: 108585, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-33910033

RESUMO

Kainate receptors (KARs) are highly expressed in the immature brain and have unique developmentally regulated functions that may be important in linking neuronal activity to morphogenesis during activity-dependent fine-tuning of the synaptic connectivity. Altered expression of KARs in the developing neural network leads to changes in glutamatergic connectivity and network excitability, which may lead to long-lasting changes in behaviorally relevant circuitries in the brain. Here, we summarize the current knowledge on physiological and morphogenic functions described for different types of KARs at immature neural circuitries, focusing on their roles in modulating synaptic transmission and plasticity as well as circuit maturation in the rodent hippocampus and amygdala. Finally, we discuss the emerging evidence suggesting that malfunction of KARs in the immature brain may contribute to the pathophysiology underlying developmentally originating neurological disorders.


Assuntos
Hipocampo/metabolismo , Rede Nervosa/metabolismo , Neurônios/metabolismo , Receptores de Ácido Caínico/metabolismo , Animais , Humanos , Plasticidade Neuronal/fisiologia , Sinapses/metabolismo
10.
Haemophilia ; 27(1): e30-e39, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33216410

RESUMO

INTRODUCTION: Characterisation of outcomes and costs of haemophilia care in common practice settings is essential for evaluation of new treatment options and for developing clinical practices. In Finland, haemophilia care is mostly centralised to University Hospitals, but treatment practices and costs in adult patients have not been systematically evaluated. AIM: This study was designed to characterise healthcare resource utilisation and treatment costs of adult inhibitor-negative haemophilia patients managed in Finnish University Hospitals. METHODS: The study was based on a nationwide cohort, which consists of all adult haemophilia A (HA; n = 120) and B (HB; n = 35) patients treated in University Hospitals from 2012 to 2016. Patient characteristics and data on healthcare utilisation and factor replacement use were collected from medical records. Direct costs of care were evaluated based on wholesale drug prices and healthcare service utilisation with standard unit costs. RESULTS: Most of HA (79%, n = 96) and HB (84%, n = 31) patients received factor replacement therapy. The median annual bleeding rate (ABR) was low, at 0.8 for HA and 0.5 for HB, also among the patients with on-demand therapy. Over 94% (n = 149) of the patients had outpatient visits during the follow-up period. The mean total annual costs of treatment ranged from €2520 to €176,330. The highest individual cost was factor replacement therapy. CONCLUSION: The outcomes of centralising the management of care to University Hospital Treatment Centres show low ABR and lower treatment costs compared with earlier reports from other high-income European populations. Management strategies, including choosing the right therapy between prophylaxis and on-demand, has been successful in Finland.


Assuntos
Hemofilia A , Adulto , Finlândia , Seguimentos , Custos de Cuidados de Saúde , Hemofilia A/tratamento farmacológico , Humanos , Aceitação pelo Paciente de Cuidados de Saúde
11.
J Cent Nerv Syst Dis ; 10: 1179573518787469, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30013417

RESUMO

The complex structure and highly variable gene expression profile of the brain makes it among the most challenging fields to study in both basic and translational biological research. Most of the brain diseases are multifactorial and despite the rapidly increasing genomic data, molecular pathways and causal links between genes and central nervous system (CNS) diseases are largely unknown. The advent of an easy and flexible CRISPR-Cas genome editing technology has rapidly revolutionized the field of functional genomics and opened unprecedented possibilities to dissect the mechanisms of CNS disease. CRISPR-Cas allows a plenitude of applications for both gene-focused and genome-wide approaches, ranging from original "gene scissors" making permanent modifications in the genome to the regulation of gene expression and epigenetics. CRISPR technology provides a unique opportunity to establish new cellular and animal models of CNS diseases and holds potential for breakthroughs in the CNS research and drug development.

12.
Front Cell Neurosci ; 10: 3, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26834558

RESUMO

Kainate type of glutamate receptors (KARs) are highly expressed during early brain development and may influence refinement of the circuitry, via modulating synaptic transmission and plasticity. KARs are also localized to axons, however, their exact roles in regulating presynaptic processes remain controversial. Here, we have used a microfluidic chamber system allowing specific manipulation of KARs in presynaptic neurons to study their functions in synaptic development and function in vitro. Silencing expression of endogenous KARs resulted in lower density of synaptophysin immunopositive puncta in microfluidically isolated axons. Various recombinant KAR subunits and pharmacological compounds were used to dissect the mechanisms behind this effect. The calcium permeable (Q) variants of the low-affinity (GluK1-3) subunits robustly increased synaptophysin puncta in axons in a manner that was dependent on receptor activity and PKA and PKC dependent signaling. Further, an associated increase in the mean active zone length was observed in electron micrographs. Selective presynaptic expression of these subunits resulted in higher success rate of evoked EPSCs consistent with higher probability of glutamate release. In contrast, the calcium-impermeable (R) variant of GluK1 or the high-affinity subunits (GluK4,5) had no effect on synaptic density or transmission efficacy. These data suggest that calcium permeable axonal KARs promote efferent connectivity by increasing the density of functional presynaptic release sites.

13.
Sci Rep ; 2: 310, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22413061

RESUMO

Kainate-type glutamate receptors (KARs) regulate synaptic transmission and neuronal excitability via multiple mechanisms, depending on their subunit composition. Presynaptic KARs tonically depress glutamatergic transmission during restricted period of synapse development; however, the molecular basis behind this effect is unknown. Here, we show that the developmental and cell-type specific expression pattern of a KAR subunit splice variant, GluK1c, corresponds to the immature-type KAR activity in the hippocampus. GluK1c localizes to dendritic contact sites at distal axons, the distal targeting being promoted by heteromerization with the subunit GluK4. Presynaptic expression of GluK1c strongly suppresses glutamatergic transmission in cell-pairs in vitro and mimics the immature-type KAR activity at CA3-CA1 synapses in vivo, at a developmental stage when the endogenous expression is already downregulated. These data support a central role for GluK1c in mediating tonic inhibition of glutamate release and the consequent effects on excitability and activity-dependent fine-tuning of the developing hippocampal circuitry.


Assuntos
Terminações Pré-Sinápticas/metabolismo , Receptores de Ácido Caínico/metabolismo , Animais , Sequência de Bases , Primers do DNA , Splicing de RNA , RNA Mensageiro/genética , Ratos , Ratos Wistar , Receptores de Ácido Caínico/genética , Frações Subcelulares/metabolismo
14.
J Neurosci ; 29(36): 11294-303, 2009 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-19741136

RESUMO

Immature hippocampal synapses express presynaptic kainate receptors (KARs), which tonically inhibit glutamate release. Presynaptic maturation involves activity-dependent downregulation of the tonic KAR activity and consequent increase in release probability; however, the molecular mechanisms underlying this developmental process are unknown. Here, we have investigated whether brain derived neurotrophic factor (BDNF), a secreted protein implicated in developmental plasticity in several areas of the brain, controls presynaptic maturation by regulating KARs. Application of BDNF in neonate hippocampal slices resulted in increase in synaptic transmission that fully occluded the immature-type KAR activity in area CA1. Conversely, genetic ablation of BDNF was associated with delayed synaptic maturation and persistent presynaptic KAR activity, suggesting a role for endogenous BDNF in the developmental regulation of KAR function. In addition, our data suggests a critical role for BDNF TrkB signaling in fast activity-dependent regulation of KARs. Selective acute inhibition of TrkB receptors using a chemical-genetic approach prevented rapid change in synapse dynamics and loss of tonic KAR activity that is typically seen in response to induction of LTP at immature synapses. Together, these data show that BDNF-TrkB-dependent maturation of glutamatergic synapses is tightly associated with a loss of endogenous KAR activity. The coordinated action of these two receptor mechanisms has immediate physiological relevance in controlling presynaptic efficacy and transmission dynamics at CA3-CA1 synapses at a stage of development when functional contact already exists but transmission is weak.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/fisiologia , Regulação para Baixo/fisiologia , Receptores de Ácido Caínico/metabolismo , Receptores Pré-Sinápticos/antagonistas & inibidores , Receptores Pré-Sinápticos/metabolismo , Sinapses/metabolismo , Transmissão Sináptica/fisiologia , Animais , Animais Recém-Nascidos , Fator Neurotrófico Derivado do Encéfalo/deficiência , Regulação para Baixo/genética , Potenciais Pós-Sinápticos Excitadores/genética , Potenciais Pós-Sinápticos Excitadores/fisiologia , Técnicas de Introdução de Genes , Hipocampo/crescimento & desenvolvimento , Hipocampo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor trkB/genética , Transdução de Sinais/genética , Sinapses/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos
15.
J Physiol ; 583(Pt 1): 145-57, 2007 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-17569736

RESUMO

The expression and functions of kainate-type glutamate receptors (KARs) in the hippocampus are developmentally regulated. In particular, presynaptic KARs depressing glutamate release are tonically activated during early postnatal development, and this activity is down-regulated in parallel with maturation of the synaptic circuitry. In order to understand the physiological relevance of the tonic KAR-mediated signalling, we have here studied the effect of long-term pharmacological activation of KARs on glutamatergic synaptic connectivity in hippocampal slice cultures where presynaptic KARs are expressed but not endogenously activated. Prolonged (16-20 h) activation of the GluR5 subunit-containing KARs using the agonist ATPA (1 microM) caused a specific and enduring increase in the number of glutamatergic synapses in area CA1, evidenced as an increase in the frequency of action potential-independent spontaneous EPSCs (mEPSCs) and in immunostaining against synaptic marker proteins. The long-term ATPA treatment had no detectable effect on GABAergic transmission or on glutamate release probability. Further, the effect of ATPA on synaptic density was independent of action potential firing and dependent on protein kinase C. A critical role of endogenous KAR activity in synaptic development was revealed by chronic treatment of the cultures with the selective GluR5 antagonist LY382884, which caused a significant impairment of glutamatergic transmission to CA1 pyramidal neurons. Together, these data suggest a role for the GluR5 subunit-containing KARs in the formation and/or stabilization of functional glutamatergic synapses in area CA1.


Assuntos
Ácido Glutâmico/metabolismo , Hipocampo/fisiologia , Receptores de Ácido Caínico/fisiologia , Sinapses/fisiologia , Potenciais de Ação/fisiologia , Animais , Hipocampo/citologia , Isoquinolinas/farmacologia , Técnicas de Patch-Clamp , Proteína Quinase C/fisiologia , Células Piramidais/fisiologia , Ratos , Ratos Wistar , Receptores de Ácido Caínico/antagonistas & inibidores , Receptores de Ácido Caínico/efeitos dos fármacos , Transmissão Sináptica/fisiologia
16.
Neuropharmacology ; 52(1): 1-11, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16919682

RESUMO

The study of long-term potentiation (LTP) has for many years been the centre of a raging debate as to whether the process is expressed by presynaptic or postsynaptic mechanisms. Here we present evidence that two forms of synaptic plasticity at CA3-CA1 synapses in the hippocampus are expressed by presynaptic changes. One form is short-term potentiation (STP) and the other a neonatal form of early-LTP (E-LTP). We review recent experimental data that suggests that this latter form of LTP involves an increase in the probability of neurotransmitter release (Pr). We describe how this is caused by the rapid down-regulation of a high affinity kainate receptor, which otherwise responds to ambient levels of l-glutamate by depressing Pr.


Assuntos
Hipocampo/citologia , Potenciação de Longa Duração/fisiologia , Plasticidade Neuronal/fisiologia , Sinapses/fisiologia , Animais , Transmissão Sináptica/fisiologia
17.
Neuron ; 50(3): 415-29, 2006 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-16675396

RESUMO

Early in development, excitatory synapses transmit with low efficacy, one mechanism for which is a low probability of transmitter release (Pr). However, little is known about the developmental mechanisms that control activity-dependent maturation of the presynaptic release. Here, we show that during early development, transmission at CA3-CA1 synapses is regulated by a high-affinity, G protein-dependent kainate receptor (KAR), which is endogenously activated by ambient glutamate. By tonically depressing glutamate release, this mechanism sets the dynamic properties of neonatal inputs to favor transmission during high frequency bursts of activity, typical for developing neuronal networks. In response to induction of LTP, the tonic activation of KAR is rapidly down regulated, causing an increase in Pr and profoundly changing the dynamic properties of transmission. Early development of the glutamatergic connectivity thus involves an activity-dependent loss of presynaptic KAR function producing maturation in the mode of excitatory transmission from CA3 to CA1.


Assuntos
Ácido Glutâmico/metabolismo , Hipocampo/crescimento & desenvolvimento , Inibição Neural/fisiologia , Vias Neurais/crescimento & desenvolvimento , Terminações Pré-Sinápticas/metabolismo , Receptores de Ácido Caínico/metabolismo , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Envelhecimento/fisiologia , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Agonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Hipocampo/citologia , Hipocampo/metabolismo , Potenciação de Longa Duração/efeitos dos fármacos , Potenciação de Longa Duração/fisiologia , Inibição Neural/efeitos dos fármacos , Vias Neurais/citologia , Vias Neurais/metabolismo , Técnicas de Cultura de Órgãos , Terminações Pré-Sinápticas/efeitos dos fármacos , Terminações Pré-Sinápticas/ultraestrutura , Ratos , Receptores Acoplados a Proteínas G/efeitos dos fármacos , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Ácido Caínico/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia
18.
J Neurosci ; 25(18): 4473-84, 2005 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-15872094

RESUMO

Kainate receptors (KARs) are highly expressed throughout the neonatal brain, but their function during development is unclear. Here, we show that the maturation of the hippocampus is associated with a switch in the functional role of presynaptic KARs. In a developmental period restricted to the first postnatal week, endogenous L-glutamate tonically activates KARs at CA3 glutamatergic synapses to regulate release in an action potential-independent manner. At synapses onto pyramidal cells, KARs inhibit glutamate release via a G-protein and PKC-dependent mechanism. In contrast, at glutamatergic terminals onto CA3 interneurons, presynaptic KARs can facilitate release in a G-protein-independent mechanism. In both cell types, however, KAR activation strongly upregulates inhibitory transmission. We show that, through the interplay of these novel diverse mechanisms, KARs strongly regulate the characteristic synchronous network activity observed in the neonatal hippocampus. By virtue of this, KARs are likely to play a central role in the development of hippocampal synaptic circuits.


Assuntos
Ácido Glutâmico/metabolismo , Hipocampo/metabolismo , Rede Nervosa/fisiologia , Neurônios/fisiologia , Receptores de Ácido Caínico/fisiologia , Animais , Animais Recém-Nascidos , Ácido Aspártico/farmacologia , Baclofeno/farmacologia , Interações Medicamentosas , Estimulação Elétrica/métodos , Agonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/efeitos da radiação , Furanos/farmacologia , Agonistas GABAérgicos/farmacologia , Antagonistas GABAérgicos/farmacologia , Guanosina Trifosfato/farmacologia , Hipocampo/citologia , Hipocampo/crescimento & desenvolvimento , Técnicas In Vitro , Interneurônios/efeitos dos fármacos , Interneurônios/fisiologia , Interneurônios/efeitos da radiação , Isoquinolinas/farmacologia , Isoxazóis/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Potenciais da Membrana/efeitos da radiação , Camundongos , Camundongos Knockout , Inibição Neural/efeitos dos fármacos , Inibição Neural/fisiologia , Inibição Neural/efeitos da radiação , Neurônios/efeitos dos fármacos , Neurônios/efeitos da radiação , Técnicas de Patch-Clamp/métodos , Picrotoxina/farmacologia , Probabilidade , Receptores de Ácido Caínico/deficiência
19.
Exp Cell Res ; 293(1): 117-28, 2004 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-14729062

RESUMO

ALP, CLP-36 and RIL form the ALP subfamily of PDZ-LIM proteins. ALP has been implicated in sarcomere function in muscle cells in association with alpha-actinin. The closely related CLP-36 is predominantly expressed in nonmuscle cells, where it localizes to actin stress fibers also in association with alpha-actinin. Here we have studied the expression and functions of RIL originally identified as a gene downregulated in H-ras-transformed cells. RIL was mostly expressed in nonmuscle epithelial cells with a pattern distinct from that of CLP-36. RIL protein was found to localize to actin stress fibers in nonmuscle cells similarly to CLP-36. However, RIL expression led to partially abnormal actin filaments showing thick irregular stress fibers not seen with CLP-36. Furthermore, live cell imaging demonstrated altered stress fiber dynamics with rapid formation of new fibers and frequent collapse of thick irregular fibers in EGFP-RIL-expressing cells. These effects may be mediated through the association of RIL with alpha-actinin, as RIL was found to associate with alpha-actinin via its PDZ domain, and RIL enhanced the ability of alpha-actinin to cosediment with actin filaments. These results implicate the RIL PDZ-LIM protein as a regulator of actin stress fiber turnover.


Assuntos
Actinina/metabolismo , Actinas/metabolismo , Proteínas de Ligação a DNA/metabolismo , Células Epiteliais/metabolismo , Fibroblastos/metabolismo , Animais , Linhagem Celular Tumoral , Células Cultivadas , Proteínas de Ligação a DNA/genética , Expressão Gênica , Glutationa Transferase/metabolismo , Proteínas de Fluorescência Verde , Proteínas de Homeodomínio/metabolismo , Humanos , Proteínas com Domínio LIM , Proteínas Luminescentes/metabolismo , Osteossarcoma/genética , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Ratos , Proteínas Recombinantes/metabolismo , Fatores de Tempo , Dedos de Zinco
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