RESUMEN
Although ubiquitous in biological studies, the enhanced green and yellow fluorescent proteins (EGFP and EYFP) were not specifically optimized for neuroscience, and their underwhelming brightness and slow expression in brain tissue limits the fidelity of dendritic spine analysis and other indispensable techniques for studying neurodevelopment and plasticity. We hypothesized that EGFP's low solubility in mammalian systems must limit the total fluorescence output of whole cells, and that improving folding efficiency could therefore translate into greater brightness of expressing neurons. By introducing rationally selected combinations of folding-enhancing mutations into GFP templates and screening for brightness and expression rate in human cells, we developed mGreenLantern, a fluorescent protein having up to sixfold greater brightness in cells than EGFP. mGreenLantern illuminates neurons in the mouse brain within 72 h, dramatically reducing lag time between viral transduction and imaging, while its high brightness improves detection of neuronal morphology using widefield, confocal, and two-photon microscopy. When virally expressed to projection neurons in vivo, mGreenLantern fluorescence developed four times faster than EYFP and highlighted long-range processes that were poorly detectable in EYFP-labeled cells. Additionally, mGreenLantern retains strong fluorescence after tissue clearing and expansion microscopy, thereby facilitating superresolution and whole-brain imaging without immunohistochemistry. mGreenLantern can directly replace EGFP/EYFP in diverse systems due to its compatibility with GFP filter sets, recognition by EGFP antibodies, and excellent performance in mouse, human, and bacterial cells. Our screening and rational engineering approach is broadly applicable and suggests that greater potential of fluorescent proteins, including biosensors, could be unlocked using a similar strategy.
Asunto(s)
Expresión Génica , Proteínas Fluorescentes Verdes/genética , Imagen Molecular , Neuronas/metabolismo , Animales , Encéfalo/metabolismo , Técnica del Anticuerpo Fluorescente , Genes Reporteros , Proteínas Fluorescentes Verdes/química , Ratones , Microscopía Fluorescente , Imagen Molecular/métodos , Mutación , Estabilidad Proteica , Proteolisis , Solubilidad , Análisis EspectralRESUMEN
The successful treatment of depressive disorders critically depends on adherence to prescribed treatment regimens. Despite increasing rates of antidepressant medication prescription, adherence to the full treatment course remains poor. Rates of antidepressant non-adherence are higher for uninsured patients and members of some marginalized racial and ethnic communities due to factors such as inequities in healthcare and access to insurance. Among patients treated in a free, student-run and faculty-supervised clinic serving uninsured patients in a majority Hispanic community in East Harlem, adherence rates are lower than those observed in patients with private or public New York State health insurance coverage. A prior study of adherence in these patients revealed that difficulty in obtaining medications from an off-site hospital pharmacy was a leading factor that patients cited for non-adherence. To alleviate this barrier to obtaining prescriptions, we tested the effectiveness of on-site, in-clinic medication dispensing for improving antidepressant medication adherence rates among uninsured patients. We found that dispensing medications directly to patients in clinic was associated with increased visits at which patients self-reported proper adherence and increased overall adherence rates. Furthermore, we found evidence that higher rates of antidepressant medication adherence were associated with more favorable treatment outcomes. All patients interviewed reported increased satisfaction with on-site dispensing. Overall, this study provides promising evidence that on-site antidepressant dispensing in a resource-limited setting improves medication adherence rates and leads to more favorable treatment outcomes with enhanced patient satisfaction.
Asunto(s)
Antidepresivos , Pacientes no Asegurados , Antidepresivos/uso terapéutico , Prescripciones de Medicamentos , Humanos , Cumplimiento de la Medicación , Satisfacción del PacienteRESUMEN
Minority groups experience higher depression but lower treatment rates. Student-run free mental health (MH) clinics, such as the East Harlem Health Outreach Partnership (EHHOP) MH clinic, address this disparity. This study scrutinized EHHOP MH's depression treatment by measuring adherence to antidepressants. Pharmacy data from seventy-nine patients were reviewed according to HEDIS criteria. Results compare EHHOP MH to New York State (NYS) Medicaid and NYS commercial insurance providers. In the acute treatment phase, EHHOP MH performed similarly to NYS Medicaid. In all other comparisons, EHHOP MH had lower adherence rates. Physician notes were reviewed to identify reasons for low adherence.
Asunto(s)
Antidepresivos/uso terapéutico , Trastorno Depresivo/tratamiento farmacológico , Trastorno Depresivo/psicología , Cumplimiento de la Medicación/psicología , Cumplimiento de la Medicación/estadística & datos numéricos , Adolescente , Adulto , Anciano , Auditoría Clínica , Centros Comunitarios de Salud Mental , Femenino , Humanos , Masculino , Medicaid , Persona de Mediana Edad , Ciudad de Nueva York , Facultades de Medicina , Estudiantes de Medicina , Estados Unidos , Adulto JovenRESUMEN
Frontal top-down cortical neurons projecting to sensory cortical regions are well-positioned to integrate long-range inputs with local circuitry in frontal cortex to implement top-down attentional control of sensory regions. How adolescence contributes to the maturation of top-down neurons and associated local/long-range input balance, and the establishment of attentional control is poorly understood. Here we combine projection-specific electrophysiological and rabies-mediated input mapping in mice to uncover adolescence as a developmental stage when frontal top-down neurons projecting from the anterior cingulate to visual cortex are highly functionally integrated into local excitatory circuitry and have heightened activity compared to adulthood. Chemogenetic suppression of top-down neuron activity selectively during adolescence, but not later periods, produces long-lasting visual attentional behavior deficits, and results in excessive loss of local excitatory inputs in adulthood. Our study reveals an adolescent sensitive period when top-down neurons integrate local circuits with long-range connectivity to produce attentional behavior.
Asunto(s)
Envejecimiento/fisiología , Atención/fisiología , Conducta Animal/fisiología , Neuronas/fisiología , Potenciales de Acción/fisiología , Animales , Channelrhodopsins/metabolismo , Giro del Cíngulo/fisiología , Masculino , Ratones Endogámicos C57BL , Modelos Neurológicos , Inhibición Neural/fisiología , Terminales Presinápticos/fisiología , Rabia/fisiopatología , Sinapsis/fisiología , Visión Ocular/fisiologíaRESUMEN
Attention is disrupted commonly in psychiatric disorders, yet mechanistic insight remains limited. Deficits in this function are associated with dorsal anterior cingulate cortex (dACC) excitotoxic lesions and pharmacological disinhibition; however, a causal relationship has not been established at the cellular level. Moreover, this association has not yet been examined in a genetically tractable species such as mice. Here, we reveal that dACC neurons causally contribute to attention processing by combining a chemogenetic approach that reversibly suppresses neural activity with a translational, touchscreen-based attention task in mice. We virally expressed inhibitory hM4Di DREADD (designer receptor exclusively activated by a designer drug) in dACC neurons, and examined the effects of this inhibitory action with the attention-based five-choice serial reaction time task. DREADD inactivation of the dACC neurons during the task significantly increased omission and correct response latencies, indicating that the neuronal activities of dACC contribute to attention and processing speed. Selective inactivation of excitatory neurons in the dACC not only increased omission, but also decreased accuracy. The effect of inactivating dACC neurons was selective to attention as response control, motivation, and locomotion remain normal. This finding suggests that dACC excitatory neurons play a principal role in modulating attention to task-relevant stimuli. This study establishes a foundation to chemogenetically dissect specific cell-type and circuit mechanisms underlying attentional behaviors in a genetically tractable species.
Asunto(s)
Atención/fisiología , Giro del Cíngulo/fisiología , Neuronas/fisiología , Receptor Muscarínico M4/fisiología , Animales , Atención/efectos de los fármacos , Clozapina/administración & dosificación , Clozapina/análogos & derivados , Antagonistas del GABA/administración & dosificación , Vectores Genéticos , Giro del Cíngulo/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Neuronas/efectos de los fármacos , Pentilenotetrazol/administración & dosificación , Tiempo de Reacción , Receptor Muscarínico M4/genética , Receptor Muscarínico M4/metabolismoRESUMEN
Early temporary windows of heightened brain plasticity called critical periods developmentally sculpt neural circuits and contribute to adult behavior. Regulatory mechanisms of visual cortex development - the preeminent model of experience-dependent critical period plasticity-actively limit adult plasticity and have proved fruitful therapeutic targets to reopen plasticity and rewire faulty visual system connections later in life. Interestingly, these molecular mechanisms have been implicated in the regulation of plasticity in other functions beyond vision. Applying mechanistic understandings of critical period plasticity in the visual cortex to fear circuitry may provide a conceptual framework for developing novel therapeutic tools to mitigate aberrant fear responses in post traumatic stress disorder. In this review, we turn to the model of experience-dependent visual plasticity to provide novel insights for the mechanisms regulating plasticity in the fear system. Fear circuitry, particularly fear memory erasure, also undergoes age-related changes in experience-dependent plasticity. We consider the contributions of molecular brakes that halt visual critical period plasticity to circuitry underlying fear memory erasure. A major molecular brake in the visual cortex, perineuronal net formation, recently has been identified in the development of fear systems that are resilient to fear memory erasure. The roles of other molecular brakes, myelin-related Nogo receptor signaling and Lynx family proteins - endogenous inhibitors for nicotinic acetylcholine receptor, are explored in the context of fear memory plasticity. Such fear plasticity regulators, including epigenetic effects, provide promising targets for therapeutic interventions.