Effects of monochromatic light in the expression patterns of the transcription factors LIM 1+2 and Islet-1 in horizontal neurons

BEJARANO, CLAUDIO ALEJANDRO,; PAGANELLI,ALEJANDRA R.; FOSSER, NICOLÁS S,; RÍOS, HUGO

cordoba

Congreso; XXVI Congreso Anual de la Sociedad de Investigación en Neurociencias; 2011

Sociedad Argentina de Investigación en Neurociencias

Effects of monochromatic light in the expression patterns of the transcription factors LIM 1+2 and Islet-1 in horizontal neurons. C.A. Bejarano, A. R. Paganelli, N. S. Fosser y H. Ríos Instituto de Biología Celular y Neurociencias .Dr. Eduardo de Robertis.. Facultad de Medicina, UBA. Paraguay 2155 Piso 3 (1121) Ciudad Autónoma de Buenos Aires. Argentina. Horizontal cells provide the pathways for local and long range interactions between photoreceptors. They are related to lateral inhibition, contrast and color processing. It is known that light modifies the intraretinal synaptic connection pattern, however, little or nothing is known about how each subtype of horizontal neurons (H1-H4) respond to a particular wavelength. To analyze the effect of spectral deprivation, chickens were reared with cycles of 12 h light-12 h dark with white or longer (LWL), medium (MWL) or short wavelength light (SWL) for 12days). Retinas were analyzed after labeling with calretinin (CR) and the transcription factors, Islet-1, LIM 1 +2.Animals reared in MWL showed an increase in the number of horizontal cells islet-1+, and a decrease in LIM 1+2. Conversely, LWL stimulated chicks showed Islet-1 diminished and LIM1+2 increased. Besides, in the SWL group we observed a decrement in LIM1+2. Also changes were observed in the pattern of horizontal cells connections with cones. These results show that monochromatic stimulation change gene expression as well as modify the connectivity of horizontal neurons. Postnatal visual experience showed plastic changes in the neuronal circuits in which subtype H1 and H3 of horizontal cells are involved. PIP00404