INVESTIGADORES
FAILLACE Maria Paula
congresos y reuniones científicas
Título:
Glutamatergic control of cell growth in the zebrafish retina
Autor/es:
CARLOS DAVID BRUQUE AND MP FAILLACE
Lugar:
Buenos Aires
Reunión:
Simposio; 2do SIMPOSIO FRANCO ARGENTINO DE NEUROCIENCIAS; 2012
Institución organizadora:
LIA DEVENIR (LaNyN, IBCN and CGPhiMC (CNRS, Univ Lyon 1 , France)
Resumen:
Glutamatergic control of cell growth in the zebrafish retina
Carlos Bruque1, Maria
Paula Faillace1,2
1Departamento de Fisiología,
Facultad de Medicina, UBA
2IQUIFIB-CONICET,
Buenos Aires, Argentina
The retina of zebrafish grows throughout animals
life from an intrinsic germinal region at the periphery of the retina called
ciliary marginal zone (CMZ). This animal model allows studying cell
proliferation and differentiation processes to generate new cell types of the
adult retina. We have described variations in the number of cells in S-phase of
the cell cycle during the light/dark photoperiod with a peak of cell
proliferation observed at the middle of the light phase. On the other hand, glutamatergic
transmission from photoreceptors to bipolar cells (BC) and from BC to ganglion cells
(GC) mediates light processing and information transmission to the visual brain
centers. We blocked the depolarization of ON BC, which are activated in
response to light, through an agonist (L-AP4) of mGluR6 receptors, whose activation
by glutamate hyperpolarizes ON BC. We also used an antagonist of AMPA receptors
DNQX, to block excitatory synapses between photoreceptors and OFF BC and between
BC and all GC (although part of the response is NMDA receptor-mediated). DNQX
treatment significantly increased proliferating cell number (measured by BrdU
incorporation for 4 h in the CMZ). Moreover, L-AP4 did not modify cell
proliferative activity. However, AP5 (an antagonist of NMDA receptors)
significantly decreased cell proliferation in the CMZ. Therefore, these results
suggest a relevant role of glutamate (possibly in response to the light/dark cycle)
in regulating mitotic activity and retinal growth in the adult zebrafish. Whether
glutamate effect occurs directly on proliferating cells or throughout other
extracellular signals is under investigation.