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Kappa-opioid receptors (KOR) control dopamine (DA) levels in the striatum and contribute significantly to the progression of drug addiction. Repeated exposure to psychostimulants has been associated with up-regulated KOR activity and increased DA levels in dorsal striatum. However, it has not been tested if both processes are linked. In this work, we studied if a mechanism mediated by KOR is contributing to the increase in DA levels in the dorsolateral striatum (DLS) after amphetamine (AMPH) sensitization. The AMPH sensitization was assessed after single or repeated once-a-day AMPH injections (1 mg/kg). Only repeated AMPH exposure produced a significant locomotor sensitization. No-net flux microdialysis was used to assess basal DA dialysate, DA extracellular concentration (C ext ), and DA uptake in DLS of anesthetized rats. The role of KOR on DA dynamics in DLS was evaluated by local perfusion (250 lM) and systemic administration (10 mg/kg) of the KOR antagonist nor-binaltorphimine. A significant decrease in DA C ext is observed in the DLS after an AMPH challenge in rats exposed to a single dose of AMPH. The decrease in DA C ext was associated with both a decreased basal DA dialysate and an increased DA uptake. Conversely, the expression of AMPH sensitization was accompanied by a significant increase in DA C ext associated with an increased basal DA dialysate and an attenuation in DA uptake. Both local and systemic administration of norbinaltorphimine reversed changes in DLS after AMPH pretreatment. These findings indicate that endogenous KOR system tunes DLS DA dynamics during the progression to AMPH sensitization.

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Objetivo: Reportar una experiencia piloto de atención por telemedicina en la especialidad de oftalmología, en el periodo de confinamiento por la pandemia Covid-19. Metodos: Estudio descriptivo. Se describen características demográficas y clínicas de pacientes atendidos en periodo de confinamiento de 10 semanas. Se evalúa la satisfacción de los pacientes y médicos participantes mediante una encuesta online Resultados: En las primeras 10 semanas, se realizaron 291 atenciones de telemedicina oftalmológica. Los principales motivos de consulta fueron afecciones inflamatorias de la superficie ocular y párpados (79,4%), seguido de requerimientos administrativos (6,5%), afecciones no inflamatorias de la superficie ocular (5,2%), sospecha de estrabismo (3,4%) y síntomas vitreoretinales (3,1%). 22 pacientes (7,5%) fueron derivados a atención presencial inmediata. El nivel de satisfacción con la prestación fue alto, tanto en médicos (100%) como en pacientes (93,4%). Conclusiones: La atención oftalmológica por telemedicina en periodo de pandemia es un instrumento de utilidad para realizar un filtro de potenciales consultas presenciales, ya sea electivas o de urgencia, y potencialmente reducir riesgo de contagio por Covid-19.