IFIBIO HOUSSAY   25014
INSTITUTO DE FISIOLOGIA Y BIOFISICA BERNARDO HOUSSAY
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Excitotoxic role of endogenous glutamate as a mediator of the damage induced by cobalt chloride in the zebrafish retina
Autor/es:
PAEZ NATALIA; FAILLACE MP; SANCHIS, PABLO ANTONIO
Lugar:
Mar del Plata
Reunión:
Congreso; LXIII Reunión Anual SAIC, LXVI Reunión Anual SAI, y Reunión Anual SAFIS; 2018
Institución organizadora:
SAIC, SAI, SAFIS
Resumen:
Zebrafish (Danio rerio) represents a useful vertebrate model for theinvestigation of human diseases and for studying mechanisms involved in tissuegrowth and regeneration. We have previously characterized a cytotoxic retinaldamage in adult zebrafish by the injection of cobalt chloride (CoCl2)into the vitreous cavity (VC), which injures mainly the photoreceptors. This causesa strong induction of the proliferative activity of multipotent Müller glia andderived progenitors that are activated for retinal repair.We divided 6 groups of zebrafishby injecting into the VC CoCl2 (injury) or saline solution (injurycontrol). Injured and uninjured zebrafish were also injected 18 h before and 6and 30 h after lesion with vehicle or glutamate ionotropic receptor antagonists(0.25 mM DNQX ?AMPAR antagonist? and 1.5 mM APV ?NMDAR antagonist?). Weperformed immunohistochemistry to label different kind of retinal cells and Hoechststaining to observe retina morphology after injury in presence or absence ofthe antagonists. We also performed behavioural studies to correlate locomotor behaviour with visualacuity of the experimental groupsvideotaping them during 1 min for further analysis. We demonstrated CoCl2 deleteriouseffect on photoreceptors and progenitor cell proliferation were significantlyreduced by treatment with DNQX and APV. At different intervals post-injuryzebrafish in the different groups showed variable behavioural responses tovisual stimuli, indicating different degrees of visual deficit. Themorphological level of retina degeneration was correlated with the deficitobserved in visual acuity for each group. Cone photoreceptor regeneration andvisual acuity recovery occurred by 25 days after injury.In conclusion, our resultsindicate that glutamate receptor antagonists showed strong neuroprotective effectsthat were evidenced both at the morphological as well as the behavioural level.We have also demonstrated CoCl2 toxic effects for retinal cells areimportantly mediated by glutamate cytotoxicity.