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1.
J Man Manip Ther ; 32(2): 166-172, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37574811

RESUMO

OBJECTIVES: The primary purpose of this study is to investigate the feasibility of using ultrasound to verify the placement of narrow-gauge dry needles within the supraspinatus and infraspinatus muscles utilizing palpation-based dry needle techniques. METHODS: This is a prospective observational study with 10 participants recruited. Each participant had a dry needle placed within the infraspinatus and supraspinatus muscles by a trained physical therapist utilizing palpation-based methods. Following needle placement, ultrasound examination was then performed to determine the feasibility of needle tip visualization within the targeted tissues. RESULTS: The needle tip was successfully visualized on ultrasound in 19/20 cases. The needle tip accurately resided in the targeted muscle tissue in each of the 19 cases it was successfully visualized. CONCLUSIONS: Narrow-gauge dry needles used in physical therapy practice can be consistently visualized in the supraspinatus and infraspinatus muscles using ultrasound imaging. Also, the palpation method utilized is an accurate means of guiding dry needles into the targeted rotator cuff muscles. These are significant findings because most physical therapy clinics do not have the benefit of real-time imaging guidance and must rely solely on palpation-based needling methods.


Assuntos
Indução Percutânea de Colágeno , Manguito Rotador , Humanos , Manguito Rotador/diagnóstico por imagem , Manguito Rotador/fisiologia , Estudos Prospectivos , Estudos de Viabilidade , Ultrassonografia
2.
J Vasc Interv Radiol ; 34(12): 2190-2196, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37673399

RESUMO

PURPOSE: To quantify perfusion changes during genicular artery embolization (GAE) with the qualitatively described "pruning" technique using parametric analysis. MATERIALS AND METHODS: A total of 12 patients underwent unilateral GAE with a total of 36 vessels embolized. Among 34 of the 36 vessels embolized, regions of interest (ROIs) were placed on parent vessels (PVs) and hyperemic target vessels (TVs) before and after GAE. For each ROI, peak intensity (PI), time to arrival (TTA), and area under the curve (AUC) were computed and compared between PV and TV. Volume of embolic administered was correlated with adverse events. RESULTS: No change was seen in PI, TTA, and AUC in the PV after GAE. Reduction in AUC (1,495.7 ± 521.5 vs 1,667.4 ± 574.0; P << .01) and PI (195.1 ± 43.8 vs 224.3 ± 49.2; P << .01) with increase in TTA (3.42 s ± 1.70 vs 1.92 s ± 1.45; P << .01) within the TV were observed after GAE. Median follow-up time was 89 days (range, 21-254 days). Reduction in clinical symptoms was also noted based on the Western-Ontario and McMaster Universities Arthritis Index total and pain scale at 1 month (total, 42.9% ± 23.0; pain, 54.4% ± 9.8; P << .01) and 3 months (total, 42.5% ± 14.9; pain, 57.8% ± 10.6; P << .01). Eight total mild adverse events (minor/self-limiting) were noted per Society of Interventional Radiology guidelines. A larger volume of embolic was observed in knees with skin changes (3.4 mL ± 0.4 vs 1.7 mL ± 0.4; P << .001). Furthermore, all skin changes were seen with embolic volumes >3.0 mL. CONCLUSIONS: Quantification of intraprocedural perfusion changes with GAE demonstrated reduced flow to the TV with maintained flow in the PV and acceptable clinical outcomes. A potential relationship between embolic volume and nontarget embolization was also highlighted.


Assuntos
Embolização Terapêutica , Humanos , Embolização Terapêutica/efeitos adversos , Embolização Terapêutica/métodos , Artérias , Perfusão , Angiografia Digital/métodos , Dor , Resultado do Tratamento
3.
Transl Sports Med ; 2023: 8824466, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38654915

RESUMO

Objectives: There is growing evidence regarding cannabinoid use in sports medicine and performance, especially cannabidiol (CBD). This study aims to determine if sports medicine physicians are recommending cannabinoids for therapeutic purposes, as well as analyze perceptions of cannabinoids within sports medicine and performance. Methods: Physician members of the American Medical Society for Sports Medicine (AMSSM) completed an anonymous survey on demographics, CBD and Cannabis recommendations, as well as attitudes toward cannabinoid products within sports medicine. Factors associated with CBD and cannabis recommendations as well as perceptual differences were found using multivariate regression modelling. Results: Responses from 333 physicians were recorded. The following groups were less likely to agree with allowing cannabis for recreational purposes: female gender (coeff. = 0.79 (0.33-1.25), p=0.001), increasing age (coeff. = 0.04 (0.02, 0.07), p < 0.001), and rural respondents (compared to baseline urban, coeff. = 1.16 (0.36, 1.95), p=0.004). Similarly, these three factors were associated with a higher likelihood of disagreeing with WADA removing cannabis from the prohibited substance list and with the NCAA allowing CBD use by collegiate athletes (p ≤ 0.045). CBD was less likely to be recommended by pediatricians, rural physicians, and academic physicians (p ≤ 0.030). Male physicians and younger physicians were less likely to identify cannabis as performance-enhancing (p ≤ 0.042). Conclusions: Sports medicine physicians have varying views on cannabinoids. While sports medicine physicians generally have favorable attitudes toward CBD and cannabis, these perceptions appear to be significantly affected by age, practice type, and gender.

4.
Phys Sportsmed ; 50(5): 419-428, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-34176424

RESUMO

OBJECTIVE: The SARS-CoV-2 pandemic has had an immense impact on healthcare, but little has been published on its impact on sports medicine physicians. This study aimed to assess the perceived impacts of the pandemic on practice changes, financial implications, and mental health of the physician members of the American Medical Society for Sports Medicine (AMSSM). METHODS: Online surveys were sent to physician members of the AMSSM, with questions asking about demographic information and personal associations to COVID-19. The main outcome measures included self-reported clinical practice volumes, visit types (telemedicine, face-to-face), Patient Health Questionnaire (PHQ-4) scores, personal finances, clarity of practice guidelines, and personal protective equipment (PPE) availability. RESULTS: A total of 825 respondents completed the initial survey, with a subset completing follow-ups. In-person clinical and procedural volumes were reported to be reduced to just 17.9% and 13.7% of the pre-pandemic baseline volumes at the first survey (March 2020), but increased to 81.1% and 77.3% (August 2020), respectively. PHQ-4 anxiety subscores significantly decreased over time (p < 0.001); younger physicians and female physicians were more likely to have higher scores (p < 0.05). Reported physician income significantly increased over time (p < 0.05), and financial concerns steadily decreased (p < 0.001). The perception of having an adequate PPE significantly increased over the study (p < 0.001) but not for having clear practice guidelines (p > 0.05). Physicians have become increasingly aware of others testing positive for the virus, but not themselves or someone they live with. CONCLUSIONS: Sports medicine physicians have been heavily impacted by the SARS-CoV-2 pandemic, with some recovery since it started. Sports medicine physicians should be aware of pandemic-related practice changes and resulting mental health and financial implications.


Assuntos
COVID-19 , Médicos , Medicina Esportiva , COVID-19/epidemiologia , Feminino , Humanos , Saúde Mental , Pandemias/prevenção & controle , Médicos/psicologia , SARS-CoV-2 , Inquéritos e Questionários
5.
Clin J Sport Med ; 32(1): e19-e22, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32032167

RESUMO

OBJECTIVES: To determine whether simple methods can improve identification of suprapatellar joint fluid during sonographic evaluation of the knee. DESIGN: Prospective cohort study. SETTING: Outpatient orthopaedic clinic. PATIENTS: Fifty-two patients were sequentially recruited from an orthopaedic clinic. INTERVENTIONS: Bilateral sonographic evaluation of the suprapatellar recess with static scanning, parapatellar pressure, or patient-initiated quadriceps contraction. MAIN OUTCOME MEASURES: Identification of fluid in the suprapatellar recess. RESULTS: Fifty-two patients (104 knees), consisting of 57 (54.8%) painful knees, were examined. Static scanning identified 45 effusions, parapatellar pressure identified 58 effusions, and quadriceps contraction identified 77 effusions. Quadriceps contraction was superior to parapatellar pressure for identifying an effusion {P < 0.001, proportion ratio [PR] = 1.33 [95% confidence interval (CI) = 1.16, 1.52]}, painful knee effusions [P = 0.036, PR = 1.24 (95% CI = 1.06-1.44)], and painless knee effusions (P = 0.006, PR = 1.50 [95% CI = 1.16-1.93]). Both methods were superior to static scanning. Parapatellar pressure identified effusions in 16.9% of knees not seen on static scanning, whereas quadriceps contraction identified effusions in 54.2% of knees not seen on static scanning. Inter-rater reliability kappa values were 0.771 for static scanning (95% CI = 0.605-0.937), 0.686 for parapatellar pressure (95% CI = 0.531-0.840), and 0.846 for quadriceps contraction (95% CI = 0.703-0.990). CONCLUSIONS: Parapatellar pressure and patient-initiated quadriceps contraction both improve sonographic detection of suprapatellar joint fluid with high inter-rater reliability; however, quadriceps contraction was superior to parapatellar pressure when assessing for grade 1 or occult effusions.


Assuntos
Articulação do Joelho , Líquido Sinovial , Humanos , Articulação do Joelho/diagnóstico por imagem , Estudos Prospectivos , Reprodutibilidade dos Testes , Ultrassonografia
6.
Handb Clin Neurol ; 158: 345-351, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30482362

RESUMO

Cervical spine trauma is a relatively rare but catastrophic event in sports. These critical situations depend on sports medicine personnel understanding every aspect of sideline care to ensure a safe and successful evaluation. This involves thorough preparation, vigilant observation of the sporting event to detect the possible mechanism of injury, and initiation of the appropriate action plan when a potentially catastrophic injury is suspected. Sideline management of cervical spine trauma requires the appropriate primary survey, with spine stabilization if necessary, secondary survey for concomitant injury, and, potentially, initiation of full spine stabilization with a spine board. In this chapter, our primary focus is discussion of the sideline evaluation of cervical spine trauma, and sideline practices designed to stabilize the athlete and minimize risk for further injury.


Assuntos
Traumatismos em Atletas/complicações , Traumatismos da Coluna Vertebral/diagnóstico , Traumatismos da Coluna Vertebral/etiologia , Humanos
7.
Pain Physician ; 20(5): E721-E726, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28727716

RESUMO

BACKGROUND: Higher body mass index (BMI) is associated with difficulty in obtaining imaging studies. While there is a small body of literature regarding the relationship between fluoroscopy time and BMI during injections for pain management, this has not been studied for intraarticular (IA) hip injections. Further, in academic training centers, trainee involvement may affect this relationship. OBJECTIVE: To determine the relationship between BMI and fluoroscopy time during IA hip injections, both with and without involvement of a trainee. STUDY DESIGN: Multicenter retrospective cohort study. SETTING: Three academic, outpatient musculoskeletal and pain medicine centers. METHODS: Patients who underwent fluoroscopically guided IA hip injections with encounter data regarding fluoroscopy time during the procedure and BMI were included. Mean and standard deviation fluoroscopy time were recorded. Comparisons were made between BMI categories of normal (18.5 - 24.9 kg/m2), overweight (25.0 - 29.9 kg/m2), and obese (greater than or equal to30.0 kg/m2). Statistical significance was set at P = 0.01 due to multiple comparisons. RESULTS: A total of 559 IA hip injections are represented in this cohort. Patients had a mean age of 58 (standard deviation [SD] 14) years and 63% were women. There was no significant difference in fluoroscopy time when comparing BMI categories (P = 0.02). However, when trainees were not involved in the injection, fluoroscopy times were significantly shorter with decreasing BMI category, with normal weight patients requiring the shortest fluoroscopy times (P = 0.01). LIMITATIONS: This study evaluated total fluoroscopy time, not radiation dose exposure per injection, which provides more direct and precise information with regard to provider and patient radiation exposure and overall safety. Future study of the impact of BMI on radiation dose during fluoroscopically guided IA hip injections is needed. CONCLUSIONS: Fluoroscopy times during IA hip injections increase with higher BMI categories in a statistically significant manner when performed by experienced clinicians but this relationship is not observed when injections are performed with a trainee in a teaching institution. This finding appears to be related to longer fluoroscopy time required to complete an IA hip injection in patients with lower BMI when a trainee is involved. KEY WORDS: Hip, injections, obesity, overweight, body mass index, fluoroscopy, radiation, pain.


Assuntos
Índice de Massa Corporal , Fluoroscopia/métodos , Quadril , Injeções Intra-Articulares/métodos , Obesidade , Adulto , Feminino , Fluoroscopia/estatística & dados numéricos , Quadril/diagnóstico por imagem , Humanos , Injeções Intra-Articulares/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo
8.
PM R ; 9(11): 1175-1178, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28483687

RESUMO

Osteogenesis imperfecta (OI) is one of the most common inherited bone disorders. These individuals are high-risk for developing fractures during their lifetime secondary to bone fragility. This case presents a female with type I OI involved in a high speed motor vehicle accident resulting in a traumatic spinal cord injury (SCI) and paraplegia. Inpatient rehabilitation was complicated by fractures of the femur and lumbar spine which impacted her level of independence upon discharge to prevent additional fractures and maintain safety. OI coupled with SCI creates a difficult combination for the rehabilitation team. This case highlights the complexity of this challenge to bring awareness to the rehabilitation team in order to safely maximize independence and minimize and prevent unnecessary injury when designing an interdisciplinary treatment plan. LEVEL OF EVIDENCE: V.


Assuntos
Fraturas do Fêmur/etiologia , Vértebras Lombares/lesões , Osteogênese Imperfeita/complicações , Traumatismos da Medula Espinal/reabilitação , Fraturas da Coluna Vertebral/etiologia , Feminino , Fraturas do Fêmur/diagnóstico por imagem , Humanos , Pessoa de Meia-Idade , Osteogênese Imperfeita/diagnóstico por imagem , Traumatismos da Medula Espinal/complicações , Fraturas da Coluna Vertebral/diagnóstico por imagem
10.
Pain Med ; 17(7): 1241-8, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26814282

RESUMO

OBJECTIVE: To determine the relationship between BMI and fluoroscopy time during intra-articular sacroiliac joint (SIJ) injections performed for a pain indication. DESIGN: Multicenter retrospective cohort study. SETTING: Three academic, outpatient pain treatment centers. SUBJECTS: Patients who underwent fluoroscopy guided SIJ injection with encounter data regarding fluoroscopy time during the procedure and body mass index (BMI). MAIN OUTCOME MEASURE: Median and 25-75% Interquartile Range (IQR) fluoroscopy time. RESULTS: 459 SIJ injections (350 patients) were included in this study. Patients had a median age of 57 (IQR 44, 70) years, and 72% were female. The median BMI in the normal weight, overweight, and obese groups were 23 (IQR 21, 24), 27 (IQR 26, 29), and 35 (IQR 32, 40), respectively. There was no significant difference in the median fluoroscopy time recorded between these BMI classes (p = 0.45). First-time SIJ injection (p = 0.53), bilateral injection (p = 0.30), trainee involvement (p = 0.47), and new trainee involvement (trainee participation during the first 2 months of the academic year) (p = 0.85) were not associated with increased fluoroscopy time for any of the three BMI categories. CONCLUSIONS: Fluoroscopy time during sacroiliac joint injection is not increased in patients who are overweight or obese, regardless of whether a first-time sacroiliac joint injection was performed, bilateral injections were performed, a trainee was involved, or a new trainee was involved.


Assuntos
Índice de Massa Corporal , Fluoroscopia , Dor Lombar/tratamento farmacológico , Radiografia Intervencionista/métodos , Adulto , Idoso , Anti-Inflamatórios/administração & dosagem , Estudos de Coortes , Feminino , Glucocorticoides/administração & dosagem , Humanos , Injeções Intra-Articulares/métodos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Articulação Sacroilíaca , Fatores de Tempo
11.
Cell Mol Neurobiol ; 30(1): 23-33, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19582570

RESUMO

We have characterized a newly generated mouse model of obesity, a mouse strain deficient in all five previously described leptin receptor isoforms. These transgenic mice, named the db (333)/db (333) mice, were identified from an ENU mutagenesis screen and carry a point mutation in the seventh exon of the db gene encoding the leptin receptor, resulting in a premature stop codon (Y(333)Stop) and gene product that lacks STAT signaling domains. db (333)/db (333) mice have a morbidly obese phenotype, with body weights diverging from wild type as early as 4 weeks of age (P < 0.05). To determine the contribution of the short isoforms of the leptin receptor in this metabolic phenotype, we performed an extensive metabolic characterization of the db (333)/db (333) mouse in relation to the well-characterized db/db mouse lacking only the long form of the leptin receptor. db (333)/db (333) mice have similar endocrine and metabolic parameters as previously described in other leptin receptor transgenic mice including db/db mice that lack only the long isoform of the leptin receptor. However, db (333)/db (333) mice show a subtle trend toward higher body weight and insulin levels, lower oxygen, carbon dioxide production, respiratory exchange ratio (RER), and temperature than db/db mice suggesting the short isoforms may play an additional role in energy homeostasis.


Assuntos
Isoformas de Proteínas/deficiência , Receptores para Leptina/deficiência , Animais , Sequência de Bases , Temperatura Corporal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Dióxido de Carbono/metabolismo , Códon sem Sentido/genética , Análise Mutacional de DNA , Glândulas Endócrinas/efeitos dos fármacos , Glândulas Endócrinas/metabolismo , Teste de Tolerância a Glucose , Hiperfagia/complicações , Inflamação/complicações , Inflamação/patologia , Insulina/farmacologia , Leptina/administração & dosagem , Leptina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Dados de Sequência Molecular , Atividade Motora/efeitos dos fármacos , Obesidade/complicações , Obesidade/metabolismo , Obesidade/patologia , Consumo de Oxigênio/efeitos dos fármacos , Fenótipo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Receptores para Leptina/genética , Receptores para Leptina/metabolismo , Respiração/efeitos dos fármacos
12.
J Neuroimmunol ; 214(1-2): 43-54, 2009 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-19640592

RESUMO

The cytokine IL-18 acts on the CNS both in physiological and pathological conditions. Its action occurs through the heterodimeric receptor IL-18Ralpha\beta. To better understand IL-18 central effects, we investigated in the mouse brain the distribution of two IL-18Ralpha transcripts, a full length and an isoform lacking the intracellular domain hypothesized to be a decoy receptor. Both isoforms were expressed in neurons throughout the brain primarily with overlapping distribution but also with some unique pattern. These data suggest that IL-18 may modulate neuronal functions and that its action may be regulated through expression of a decoy receptor.


Assuntos
Encéfalo/metabolismo , Subunidade alfa de Receptor de Interleucina-18/metabolismo , Interleucina-18/metabolismo , Processamento Alternativo , Animais , Encéfalo/imunologia , Cerebelo/metabolismo , Córtex Cerebral/metabolismo , Éxons , Hipocampo/metabolismo , Hipotálamo/metabolismo , Imuno-Histoquímica , Hibridização In Situ , Interleucina-18/imunologia , Subunidade alfa de Receptor de Interleucina-18/imunologia , Subunidade beta de Receptor de Interleucina-18/metabolismo , Íntrons , Camundongos , Camundongos Endogâmicos C57BL , Isoformas de Proteínas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Gênica
13.
Neuropeptides ; 42(4): 387-97, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18554714

RESUMO

Neuropeptide galanin modulates a variety of central nervous system functions by signaling through three G-protein-coupled receptor subtypes, GalR1 through GalR3. Galanin and its receptors are expressed at high levels in the limbic structures of the rodent brain. Intracerebroventricular injection of galanin has been shown to modulate depression and anxiety-like behaviors in the rat. We have previously shown that chronic antidepressant treatments increase the binding of a GalR2-preferring ligand, galanin (2-11), to the dorsal raphe nucleus (DRN) of the rat, which, along with the finding that intra-DRN infusion of galanin (2-11) increases the release of serotonin in the hippocampus, suggests that GalR2 signaling might exert antidepressant-like actions by modulating ascending serotonergic outflow. Recently, two research groups reported their phenotypic analysis of a GalR2 knockout (GalR2KO) mouse line, produced by gene-trapping method and maintained on a 129S1/SvImJ genetic background. The only positive finding in that GalR2KO mouse line was an anxiogenic-like phenotype specific to the elevated plus-maze. Because it is known that genetic background can affect the outcome of behavioral tests, in the present study, we analyzed a separate GalR2KO line, which was produced by targeted deletion and maintained on a C57BL/6 background, using a different set of depression- and anxiety-related tests. GalR2KO mice exhibited a more persistent depressive-like phenotype in the learned helplessness paradigm as well as increased immobility in the tail suspension test when results from the present studies were combined by fixed effect meta-analysis with that reported by Gottsch and colleagues. GalR2KO mutants showed anxiety-like behavior comparable to wild-type littermates in the elevated plus-maze, open-field, and light-dark transfer tests. The present findings are consistent with a predicted antidepressant-like effect of GalR2 signaling, suggesting that GalR2 might be a valid drug target for depressive disorders.


Assuntos
Comportamento Animal/fisiologia , Depressão/metabolismo , Receptor Tipo 2 de Galanina/metabolismo , Animais , Antidepressivos Tricíclicos/farmacologia , Comportamento Animal/efeitos dos fármacos , Desipramina/farmacologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Testes Neuropsicológicos , Fenótipo , Ratos , Receptor Tipo 2 de Galanina/genética
14.
Dev Neurobiol ; 68(3): 409-19, 2008 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-18161851

RESUMO

Transcellular interactions between neuroligins (NL) and beta-neurexin have been widely documented to promote maturation and function of both glutamatergic and GABAergic synapses. Recently it has been shown that neuroligin-1 plays a similar role at nicotinic synapses on chick ciliary ganglion neurons in culture, acting from the postsynaptic side to enhance transmitter release from adjacent cholinergic terminals and boost nicotinic input to the cells. We show here that the ciliary ganglion expresses three forms of neuroligin as well as two beta-neurexins and an alpha-neurexin. Overexpression of the beta-neurexins, but not the alpha-neurexin, can induce clustering of endogenous PSD-95 in adjacent neurons, presumably engaging neuroligin in the postsynaptic cell. The trans effects of beta-neurexins are selective; though both alpha3- and alpha7-containing nicotinic receptors are available on opposing cells, beta-neurexins induce coclustering of alpha3- but not alpha7-containing nicotinic receptors. Overexpression of other putative synaptogenic molecules, including SynCAM and L1, are ineffective at trans-clustering of PSD-95 on adjacent neurons. The beta-neurexins also exert a cis effect, coclustering presynaptic markers along with beta-neurexin in neurites juxtaposed to postsynaptic proteins, consistent with organizing presynaptic components as well. Striated muscle, the synaptic target of ciliary neurons in vivo, also expresses neuroligin. The results demonstrate that NL and neurexins are present at multiple sites in nicotinic cholinergic pathways and suggest the possibility of both cis- and trans-interactions to influence nicotinic signaling.


Assuntos
Gânglios Parassimpáticos/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Animais , Moléculas de Adesão Celular Neuronais , Células Cultivadas , Embrião de Galinha , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Membrana/genética , Proteínas do Tecido Nervoso/genética , Neurônios/citologia , Terminações Pré-Sinápticas/metabolismo , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismo , Transfecção/métodos , Receptor Nicotínico de Acetilcolina alfa7
15.
Dev Biol ; 307(1): 79-91, 2007 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-17521624

RESUMO

Neuroligins are cell adhesion molecules that interact with neurexins on adjacent cells to promote glutamatergic and GABAergic synapse formation in culture. We show here that neuroligin enhances nicotinic synapses on neurons in culture, increasing synaptic input. When neuroligin is overexpressed in neurons, the extracellular domain induces presynaptic specializations in adjacent cholinergic neurons as visualized by SV2 puncta. The intracellular domain is required to translate the SV2 puncta into synaptic input as reflected by increases in the frequency of spontaneous mini-synaptic currents. The PDZ-binding motif of neuroligin is not needed for these effects. Together, the extracellular and proximal intracellular domains of neuroligin are sufficient to induce presynaptic specializations, align them over postsynaptic receptor clusters, and increase synaptic function. Manipulation of endogenous neuroligin with beta-neurexin-expressing cells confirms its presence; repressing function with dominant negative constructs and inhibitory shRNA shows that endogenous neuroligin helps confer functionality on existing nicotinic synaptic contacts. Endogenous neuroligin does not appear to be required, however, for initial formation of the contacts, suggesting that other components under these conditions can also initiate synapse formation. The results indicate that postsynaptic neuroligin is important for functional nicotinic synapses on neurons and that the effects achieved will likely depend on neuroligin levels.


Assuntos
Proteínas de Membrana/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Terminações Pré-Sinápticas/fisiologia , Sinapses/fisiologia , Animais , Moléculas de Adesão Celular Neuronais , Células Cultivadas , Embrião de Galinha , Potenciais Pós-Sinápticos Excitadores/fisiologia , Humanos , Neurônios/citologia , Nicotina , Sinapses/química , Transfecção
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