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1.
J Clin Nurs ; 33(6): 2226-2236, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38476057

RESUMO

AIMS: To assess the effects of COVID-19 pandemic on clinical variables as part of the routine clinical monitoring of patients with chronic diseases in primary care. DESIGN: A prospective longitudinal study was conducted in primary care centres of the Andalusian Health Service. METHODS: Data were recorded before the pandemic (T1), during the declaration of the state of emergency (T2) and in the transition phase (T3). The Barthel index and the Short Portable Mental Status Questionnaire (SPMSQ) were used to analyse functional and cognitive changes at the three time points. HbA1c, systolic and diastolic blood pressure, heart rate, BMI and lipid levels were assessed as clinical variables. Descriptive statistics and non-parametric chi-square test were used for analysis. STROBE checklist was used for the preparation of this paper. RESULTS: A total fo148 patients with chronic conditions were included in the analysis. Data analysis revealed in T2 only significant reductions in BMI, total levels of cholesterol and HDL during the onset of the pandemic. Barthel Index, SPMSQ, blood pressure and triglycerides and LDL levels worsened in T2, and the negative effects were maintained in T3. Compared to pre-pandemic values, HbA1c levels improved in T3, but HDL levels worsened. CONCLUSIONS: COVID-19 has drastically disrupted several functional, cognitive and biological variables. These results may be useful in identifying clinical parameters that deserve closer attention in the case of a new health crisis. Further studies are needed to assess the potential impacts of each specific chronic condition. IMPACT: Cognitive and functional status, blood pressure and triglycerides and LDL levels worsen in short term, maintaining the negative effects in medium-term.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , Estudos Longitudinais , Estudos Prospectivos , Masculino , Doença Crônica , Feminino , Pessoa de Meia-Idade , Idoso , Pandemias , SARS-CoV-2 , Espanha/epidemiologia , Adulto , Atenção Primária à Saúde
2.
Neurol Int ; 15(4): 1253-1272, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37873836

RESUMO

Type 2 diabetes mellitus (T2D) is a metabolic disease reaching pandemic levels worldwide. In parallel, Alzheimer's disease (AD) and vascular dementia (VaD) are the two leading causes of dementia in an increasingly long-living Western society. Numerous epidemiological studies support the role of T2D as a risk factor for the development of dementia. However, few basic science studies have focused on the possible mechanisms involved in this relationship. On the other hand, this review of the literature also aims to explore the relationship between T2D, AD and VaD. The data found show that there are several alterations in the central nervous system that may be promoting the development of T2D. In addition, there are some mechanisms by which T2D may contribute to the development of neurodegenerative diseases such as AD or VaD.

3.
Artigo em Inglês | MEDLINE | ID: mdl-37297528

RESUMO

The development of the personality of university students can determine their affinities for certain disciplines; therefore, it is important to know their specific socio-demographic and motivational profile, what motivates them to start a certain university degree and what encourages them to continue with it, which can help to adapt the teaching methodology. A total of 292 university students from the University of Granada (Ceuta and Melilla campuses) participated in this quantitative study with a descriptive, cross-sectional design, in which motivation and social skills were analysed. Among the results, it can be highlighted that the student population is mainly female, with a higher level of motivation. Sociability, communication, thinking (optimistic or pessimistic), empathy and self-confidence are skills that affect university students' motivation levels. This study highlights the importance and impact of students' motivation on their learning and the development of their social competence, so it is essential to carry out educational interventions that promote these types of skills, especially in cross-border contexts, which can be demotivating environments.


Assuntos
Aprendizagem , Motivação , Humanos , Feminino , Masculino , Universidades , Estudos Transversais , Estudantes
4.
Int J Mol Sci ; 24(10)2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37240018

RESUMO

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with unknown etiology. Many metabolic alterations occur during ALS progress and can be used as a method of pre-diagnostic and early diagnosis. Dyslipidemia is one of the physiological changes observed in numerous ALS patients. The aim of this study is to analyze the possible relationship between the rate of disease progression (functional rating scale (ALS-FRS)) and the plasma lipid levels at the early stage of ALS. A systematic review was carried out in July 2022. The search equation was "Triglycerides AND amyotrophic lateral sclerosis" and its variants. Four meta-analyses were performed. Four studies were included in the meta-analysis. No significant differences were observed between the lipid levels (total cholesterol, triglycerides, HDL cholesterol, and LDL cholesterol) and the ALS-FRS score at the onset of the disease. Although the number of studies included in this research was low, the results of this meta-analytic study suggest that there is no clear relationship between the symptoms observed in ALS patients and the plasma lipid levels. An increase in research, as well as an expansion of the geographical area, would be of interest.


Assuntos
Esclerose Lateral Amiotrófica , Doenças Neurodegenerativas , Humanos , Triglicerídeos , HDL-Colesterol , LDL-Colesterol
5.
Int J Mol Sci ; 24(9)2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37175748

RESUMO

Aging continues to be the main cause of the development of Alzheimer's, although it has been described that certain chronic inflammatory pathologies can negatively influence the progress of dementia, including obesity and hyperlipidemia. In this sense, previous studies have shown a relationship between low-density lipoprotein receptor (LDLR) and the amyloid-beta (Aß) binding activity, one of the main neuropathological features of Alzheimer's disease (AD). LDLR is involved in several processes, including lipid transport, regulation of inflammatory response and lipid metabolism. From this perspective, LDLR-/- mice are a widely accepted animal model for the study of pathologies associated with alterations in lipid metabolism, such as familial hypercholesterolemia, cardiovascular diseases, metabolic syndrome, or early cognitive decline. In this context, we induced hyperlipidemia in LDLR-/- mice after feeding with a high-saturated fatty acid diet (HFD) for 44 weeks. LDLR-/--HFD mice exhibited obesity, hypertriglyceridemia, higher glucose levels, and early hepatic steatosis. In addition, HFD increased plasmatic APOE and ubiquitin 60S levels. These proteins are related to neuronal integrity and health maintenance. In agreement, we detected mild cognitive dysfunctions in mice fed with HFD, whereas LDLR-/--HFD mice showed a more severe and evident affectation. Our data suggest central nervous system dysfunction is associated with a well-established metabolic syndrome. As a late consequence, metabolic syndrome boots many behavioral and pathological alterations recognized in dementia, supporting that the control of metabolic parameters could improve cognitive preservation and prognosis.


Assuntos
Doença de Alzheimer , Hiperlipidemias , Síndrome Metabólica , Camundongos , Animais , Síndrome Metabólica/genética , Síndrome Metabólica/complicações , Dieta Hiperlipídica , Doença de Alzheimer/patologia , Obesidade/complicações , Hiperlipidemias/complicações , Cognição , Ácidos Graxos , Receptores de LDL/genética , Receptores de LDL/metabolismo , Modelos Animais de Doenças
6.
Pharmaceutics ; 15(3)2023 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-36986631

RESUMO

Parkinson's disease (PD) is a neurodegenerative pathology, the origin of which is associated with the death of neuronal cells involved in the production of dopamine. The prevalence of PD has increased exponentially. The aim of this review was to describe the novel treatments for PD that are currently under investigation and study and the possible therapeutic targets. The pathophysiology of this disease is based on the formation of alpha-synuclein folds that generate Lewy bodies, which are cytotoxic and reduce dopamine levels. Most pharmacological treatments for PD target alpha-synuclein to reduce the symptoms. These include treatments aimed at reducing the accumulation of alpha-synuclein (epigallocatechin), reducing its clearance via immunotherapy, inhibiting LRRK2, and upregulating cerebrosidase (ambroxol). Parkinson's disease continues to be a pathology of unknown origin that generates a significant social cost for the patients who suffer from it. Although there is still no definitive cure for this disease at present, there are numerous treatments available aimed at reducing the symptomatology of PD in addition to other therapeutic alternatives that are still under investigation. However, the therapeutic approach to this pathology should include a combination of pharmacological and non-pharmacological strategies to maximise outcomes and improve symptomatological control in these patients. It is therefore necessary to delve deeper into the pathophysiology of the disease in order to improve these treatments and therefore the quality of life of the patients.

7.
Biomedicines ; 11(1)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36672646

RESUMO

Life expectancy has been boosted in recent decades at expenses of increasing the age-associated diseases. Dementia, for its incidence, stands out among the pathologies associated with aging. The exacerbated cognitive deterioration disables people from carrying out their daily lives autonomously and this incidence increases exponentially after 65 years of age. The etiology of dementia is a miscellaneous combination of risk factors that restrain the quality of life of our elderly. In this sense, it has been established that some metabolic pathologies such as obesity and diabetes act as a risk factor for dementia development. In contrast, a high educational level, as well as moderate physical activity, have been shown to be protective factors against cognitive impairment and the development of dementia. In the present study, we have evaluated the metabolic composition of a population between 60-90 years old, mentally healthy and with high academic degrees. After assessing agility in mental state, we have established relationships between their cognitive abilities and their body composition. Our data support that excess body fat is associated with poorer maintenance of cognition, while higher percentages of muscle mass are associated with the best results in the cognitive tests.

8.
Diagnostics (Basel) ; 12(12)2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36553100

RESUMO

The management of chronic diseases in the midst of the COVID-19 pandemic is especially challenging, and reducing potential psychological harm is essential. This review aims to determine the prevalence of depression during the COVID-19 pandemic in patients with chronic disease, and to characterize the impacts of related factors. A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The meta-analysis was performed using StatsDirect software. The review identified 33 articles with a total of 50,905 patients with chronic diseases. Four meta-analyses were performed to estimate the prevalence of depression. In diabetic patients, the prevalence ranged from 17% (95% CI = 7-31) (PHQ-9) to 33% (95% CI = 16-51) (PHQ-8); in obese patients, the prevalence was 48% (95% CI = 26-71); and in hypertensive patients, the prevalence was 18% (95% CI = 13-24). The factors significantly associated with depression were female sex, being single, deterioration in the clinical parameters of diabetes, a decrease in self-care behavior, reduced physical activity and sleep time and fear of contagion. The COVID-19 pandemic has significantly increased levels of depression among persons with chronic disease. Pandemics and other emergency events have a major impact on mental health, so early psychological interventions and health management policies are needed to reinforce chronic patients' physical and mental health.

9.
Pharmaceutics ; 14(6)2022 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-35745693

RESUMO

Alzheimer's disease (AD) is the most common cause of dementia. The pathophysiology of this disease is characterized by the accumulation of amyloid-ß, leading to the formation of senile plaques, and by the intracellular presence of neurofibrillary tangles based on hyperphosphorylated tau protein. In the therapeutic approach to AD, we can identify three important fronts: the approved drugs currently available for the treatment of the disease, which include aducanumab, donepezil, galantamine, rivastigmine, memantine, and a combination of memantine and donepezil; therapies under investigation that work mainly on Aß pathology and tau pathology, and which include γ-secretase inhibitors, ß-secretase inhibitors, α-secretase modulators, aggregation inhibitors, metal interfering drugs, drugs that enhance Aß clearance, inhibitors of tau protein hyperphosphorylation, tau protein aggregation inhibitors, and drugs that promote the clearance of tau, and finally, other alternative therapies designed to improve lifestyle, thus contributing to the prevention of the disease. Therefore, the aim of this review was to analyze and describe current treatments and possible future alternatives in the therapeutic approach to AD.

10.
Front Mol Neurosci ; 14: 788039, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34938160

RESUMO

Intrinsic membrane excitability (IME) sets up neuronal responsiveness to synaptic drive. Several neurotransmitters and neuromodulators, acting through G-protein-coupled receptors (GPCRs), fine-tune motoneuron (MN) IME by modulating background K+ channels TASK1. However, intracellular partners linking GPCRs to TASK1 modulation are not yet well-known. We hypothesized that isoform 2 of rho-kinase (ROCK2), acting as downstream GPCRs, mediates adjustment of MN IME via TASK1. Electrophysiological recordings were performed in hypoglossal MNs (HMNs) obtained from adult and neonatal rats, neonatal knockout mice for TASK1 (task1 -/-) and TASK3 (task3 -/-, the another highly expressed TASK subunit in MNs), and primary cultures of embryonic spinal cord MNs (SMNs). Small-interfering RNA (siRNA) technology was also used to knockdown either ROCK1 or ROCK2. Furthermore, ROCK activity assays were performed to evaluate the ability of various physiological GPCR ligands to stimulate ROCK. Microiontophoretically applied H1152, a ROCK inhibitor, and siRNA-induced ROCK2 knockdown both depressed AMPAergic, inspiratory-related discharge activity of adult HMNs in vivo, which mainly express the ROCK2 isoform. In brainstem slices, intracellular constitutively active ROCK2 (aROCK2) led to H1152-sensitive HMN hyper-excitability. The aROCK2 inhibited pH-sensitive and TASK1-mediated currents in SMNs. Conclusively, aROCK2 increased IME in task3 -/-, but not in task1 -/- HMNs. MN IME was also augmented by the physiological neuromodulator lysophosphatidic acid (LPA) through a mechanism entailing Gαi/o-protein stimulation, ROCK2, but not ROCK1, activity and TASK1 inhibition. Finally, two neurotransmitters, TRH, and 5-HT, which are both known to increase MN IME by TASK1 inhibition, stimulated ROCK2, and depressed background resting currents via Gαq/ROCK2 signaling. These outcomes suggest that LPA and several neurotransmitters impact MN IME via Gαi/o/Gαq-protein-coupled receptors, downstream ROCK2 activation, and subsequent inhibition of TASK1 channels.

11.
Biomedicines ; 9(12)2021 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-34944723

RESUMO

Alzheimer's disease (AD) is the most common cause of dementia. It is characterized by cognitive decline and progressive memory loss. The aim of this review was to update the state of knowledge on the pathophysiological mechanisms, diagnostic methods and therapeutic approach to AD. Currently, the amyloid cascade hypothesis remains the leading theory in the pathophysiology of AD. This hypothesis states that amyloid-ß (Aß) deposition triggers a chemical cascade of events leading to the development of AD dementia. The antemortem diagnosis of AD is still based on clinical parameters. Diagnostic procedures in AD include fluid-based biomarkers such as those present in cerebrospinal fluid and plasma or diagnostic imaging methods. Currently, the therapeutic armory available focuses on symptom control and is based on four pillars: pharmacological treatment where acetylcholinesterase inhibitors stand out; pharmacological treatment under investigation which includes drugs focused on the control of Aß pathology and tau hyperphosphorylation; treatment focusing on risk factors such as diabetes; or nonpharmacological treatments aimed at preventing development of the disease or treating symptoms through occupational therapy or psychological help. AD remains a largely unknown disease. Further research is needed to identify new biomarkers and therapies that can prevent progression of the pathology.

12.
Neuropathol Appl Neurobiol ; 47(7): 1004-1018, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33508894

RESUMO

AIMS: Alterations in excitability represent an early hallmark in Amyotrophic Lateral Sclerosis (ALS). Therefore, deciphering the factors that impact motor neuron (MN) excitability offers an opportunity to uncover further aetiopathogenic mechanisms, neuroprotective agents, therapeutic targets, and/or biomarkers in ALS. Here, we hypothesised that the lipokine lysophosphatidic acid (lpa) regulates MN excitability via the G-protein-coupled receptor lpa1 . Then, modulating lpa1 -mediated signalling might affect disease progression in the ALS SOD1-G93A mouse model. METHODS: The influence of lpa-lpa1 signalling on the electrical properties, Ca2+ dynamic and survival of MNs was tested in vitro. Expression of lpa1 in cultured MNs and in the spinal cord of SOD1-G93A mice was analysed. ALS mice were chronically treated with a small-interfering RNA against lpa1 (siRNAlpa1 ) or with the lpa1 inhibitor AM095. Motor skills, MN loss, and lifespan were evaluated. RESULTS: AM095 reduced MN excitability. Conversely, exogenous lpa increased MN excitability by modulating task1 'leak' potassium channels downstream of lpa1 . Lpa-lpa1 signalling evoked an excitotoxic response in MNs via voltage-sensitive calcium channels. Cultured SOD1-G93A MNs displayed lpa1 upregulation and heightened vulnerability to lpa. In transgenic mice, lpa1 was upregulated mostly in spinal cord MNs before cell loss. Chronic administration of either siRNAlpa1 or AM095 reduced lpa1 expression at least in MNs, delayed MN death, improved motor skills, and prolonged life expectancy of ALS mice. CONCLUSIONS: These results suggest that stressed lpa-lpa1 signalling contributes to MN degeneration in SOD1-G93A mice. Consequently, disrupting lpa1 slows down disease progression. This highlights LPA1 signalling as a potential target and/or biomarker in ALS.


Assuntos
Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Neurônios Motores/patologia , Receptores de Ácidos Lisofosfatídicos/metabolismo , Superóxido Dismutase-1/genética , Esclerose Lateral Amiotrófica/genética , Animais , Modelos Animais de Doenças , Progressão da Doença , Camundongos Transgênicos , Microglia/patologia , Degeneração Neural/genética , Degeneração Neural/patologia , Medula Espinal/patologia
13.
Nat Commun ; 10(1): 3784, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31439839

RESUMO

Disruption in membrane excitability contributes to malfunction and differential vulnerability of specific neuronal subpopulations in a number of neurological diseases. The adaptor protein p11, and background potassium channel TASK1, have overlapping distributions in the CNS. Here, we report that the transcription factor Sp1 controls p11 expression, which impacts on excitability by hampering functional expression of TASK1. In the SOD1-G93A mouse model of ALS, Sp1-p11-TASK1 dysregulation contributes to increased excitability and vulnerability of motor neurons. Interference with either Sp1 or p11 is neuroprotective, delaying neuron loss and prolonging lifespan in this model. Nitrosative stress, a potential factor in human neurodegeneration, stimulated Sp1 expression and human p11 promoter activity, at least in part, through a Sp1-binding site. Disruption of Sp1 or p11 also has neuroprotective effects in a traumatic model of motor neuron degeneration. Together our work suggests the Sp1-p11-TASK1 pathway is a potential target for treatment of degeneration of motor neurons.


Assuntos
Esclerose Lateral Amiotrófica/patologia , Anexina A2/metabolismo , Neurônios Motores/patologia , Degeneração Neural/patologia , Proteínas do Tecido Nervoso/genética , Canais de Potássio de Domínios Poros em Tandem/genética , Proteínas S100/metabolismo , Fator de Transcrição Sp1/metabolismo , Esclerose Lateral Amiotrófica/etiologia , Animais , Membrana Celular/patologia , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Masculino , Potenciais da Membrana , Camundongos , Camundongos Transgênicos , Neurônios Motores/citologia , Degeneração Neural/etiologia , Proteínas do Tecido Nervoso/metabolismo , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Cultura Primária de Células , Regiões Promotoras Genéticas , Ratos , Fator de Transcrição Sp1/genética , Medula Espinal/citologia , Medula Espinal/patologia
14.
PLoS Biol ; 13(5): e1002153, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25996636

RESUMO

Synaptic communication is a dynamic process that is key to the regulation of neuronal excitability and information processing in the brain. To date, however, the molecular signals controlling synaptic dynamics have been poorly understood. Membrane-derived bioactive phospholipids are potential candidates to control short-term tuning of synaptic signaling, a plastic event essential for information processing at both the cellular and neuronal network levels in the brain. Here, we showed that phospholipids affect excitatory and inhibitory neurotransmission by different degrees, loci, and mechanisms of action. Signaling triggered by lysophosphatidic acid (LPA) evoked rapid and reversible depression of excitatory and inhibitory postsynaptic currents. At excitatory synapses, LPA-induced depression depended on LPA1/Gαi/o-protein/phospholipase C/myosin light chain kinase cascade at the presynaptic site. LPA increased myosin light chain phosphorylation, which is known to trigger actomyosin contraction, and reduced the number of synaptic vesicles docked to active zones in excitatory boutons. At inhibitory synapses, postsynaptic LPA signaling led to dephosphorylation, and internalization of the GABAAγ2 subunit through the LPA1/Gα12/13-protein/RhoA/Rho kinase/calcineurin pathway. However, LPA-induced depression of GABAergic transmission was correlated with an endocytosis-independent reduction of GABAA receptors, possibly by GABAAγ2 dephosphorylation and subsequent increased lateral diffusion. Furthermore, endogenous LPA signaling, mainly via LPA1, mediated activity-dependent inhibitory depression in a model of experimental synaptic plasticity. Finally, LPA signaling, most likely restraining the excitatory drive incoming to motoneurons, regulated performance of motor output commands, a basic brain processing task. We propose that lysophospholipids serve as potential local messengers that tune synaptic strength to precedent activity of the neuron.


Assuntos
Lisofosfolipídeos/metabolismo , Neurônios Motores/fisiologia , Plasticidade Neuronal , Transmissão Sináptica , Animais , Calcineurina/metabolismo , Feminino , Masculino , Camundongos , Técnicas de Patch-Clamp , Gravidez , Ratos Wistar , Receptores de GABA-A/metabolismo , Sinapses/metabolismo , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo
15.
Neuropharmacology ; 92: 69-79, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25595101

RESUMO

Impairment of motor skills is one of the most common acute adverse effects of cannabis. Related studies have focused mainly on psychomotor alterations, and little is known about the direct impact of cannabinoids (CBs) on motoneuron physiology. As key modulators of synaptic function, CBs regulate multiple neuronal functions and behaviors. Presynaptic CB1 mediates synaptic strength depression by inhibiting neurotransmitter release, via a poorly understood mechanism. The present study examined the effect of CB agonists on excitatory synaptic inputs incoming to hypoglossal motoneurons (HMNs) in vitro and in vivo. The endocannabinoid anandamide (AEA) and the synthetic CB agonist WIN 55,212-2 rapidly and reversibly induced short-term depression (STD) of glutamatergic synapses on motoneurons by a presynaptic mechanism. Presynaptic effects were fully reversed by the CB1-selective antagonist AM281. Electrophysiological and electron microscopy analysis showed that WIN 55,212-2 reduced the number of synaptic vesicles (SVs) docked to active zones in excitatory boutons. Given that AM281 fully abolished depolarization-induced depression of excitation, motoneurons can be feasible sources of CBs, which in turn act as retrograde messengers regulating synaptic function. Finally, microiontophoretic application of the CB agonist O-2545 reversibly depressed, presumably via CB1, glutamatergic inspiratory-related activity of HMNs in vivo. Therefore, evidence support that CBs, via presynaptic CB1, induce excitatory STD by reducing the readily releasable pool of SVs at excitatory synapses, then attenuating motoneuron activity. These outcomes contribute a possible mechanistic basis for cannabis-associated motor performance disturbances such as ataxia, dysarthria and dyscoordination.


Assuntos
Tronco Encefálico/citologia , Agonistas de Receptores de Canabinoides/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Vesículas Sinápticas/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Benzopiranos/farmacologia , Tronco Encefálico/ultraestrutura , Relação Dose-Resposta a Droga , Estimulação Elétrica , Fármacos Atuantes sobre Aminoácidos Excitatórios/farmacologia , Feminino , Imidazóis/farmacologia , Técnicas In Vitro , Iontoforese , Masculino , Microscopia Eletrônica de Transmissão , Neurônios Motores/citologia , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/fisiologia , Técnicas de Patch-Clamp , Ratos , Ratos Wistar , Sinapses/ultraestrutura
16.
J Neurosci ; 32(1): 68-84, 2012 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-22219271

RESUMO

Rho-associated kinase (ROCK) regulates neural cell migration, proliferation and survival, dendritic spine morphology, and axon guidance and regeneration. There is, however, little information about whether ROCK modulates the electrical activity and information processing of neuronal circuits. At neonatal stage, ROCKα is expressed in hypoglossal motoneurons (HMNs) and in their afferent inputs, whereas ROCKß is found in synaptic terminals on HMNs, but not in their somata. Inhibition of endogenous ROCK activity in neonatal rat brainstem slices failed to modulate intrinsic excitability of HMNs, but strongly attenuated the strength of their glutamatergic and GABAergic synaptic inputs. The mechanism acts presynaptically to reduce evoked neurotransmitter release. ROCK inhibition increased myosin light chain (MLC) phosphorylation, which is known to trigger actomyosin contraction, and reduced the number of synaptic vesicles docked to active zones in excitatory boutons. Functional and ultrastructural changes induced by ROCK inhibition were fully prevented/reverted by MLC kinase (MLCK) inhibition. Furthermore, ROCK inhibition drastically reduced the phosphorylated form of p21-associated kinase (PAK), which directly inhibits MLCK. We conclude that endogenous ROCK activity is necessary for the normal performance of motor output commands, because it maintains afferent synaptic strength, by stabilizing the size of the readily releasable pool of synaptic vesicles. The mechanism of action involves a tonic inhibition of MLCK, presumably through PAK phosphorylation. This mechanism might be present in adults since unilateral microinjection of ROCK or MLCK inhibitors into the hypoglossal nucleus reduced or increased, respectively, whole XIIth nerve activity.


Assuntos
Nervo Hipoglosso/enzimologia , Neurônios Motores/enzimologia , Terminações Pré-Sinápticas/enzimologia , Transmissão Sináptica/fisiologia , Vesículas Sinápticas/enzimologia , Quinases Associadas a rho/fisiologia , Animais , Animais Recém-Nascidos , Feminino , Nervo Hipoglosso/crescimento & desenvolvimento , Nervo Hipoglosso/ultraestrutura , Sistema de Sinalização das MAP Quinases/fisiologia , Masculino , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/ultraestrutura , Técnicas de Cultura de Órgãos , Terminações Pré-Sinápticas/metabolismo , Terminações Pré-Sinápticas/ultraestrutura , Ratos , Ratos Wistar , Transmissão Sináptica/efeitos dos fármacos , Vesículas Sinápticas/metabolismo , Vesículas Sinápticas/ultraestrutura , Quinases Associadas a rho/antagonistas & inibidores
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