Neural Circuits and Systems Neuroscience
Author: Ana Paulova Contreras Vera | Email: apavlovac@fbmc.fcen.uba.ar
Ana Contreras1°, Julieta Sztarker1°2°
1° Instituto de Fisiología, BiologíaMolecular y Neurociencias (IFIBYNE), UBA-CONICET, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales.
2° Departamento de Fisiología, Biología Molecular y Celular “Dr HéctorMaldonado”, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires
Semiterrestrial crabs possess a highly developed visual system and display conspicuous visually guided behaviors. The brain structures processing visual information are called optic neuropils. These are highly ordered structures containing thousands of retinotopically-arranged columns performing the parallel processing of visual signals from different points in space. From periphery to center, they are called: lamina, medulla, and lobula complex (composed by the lobula and the lobula plate). These names are shared with insects given the similar organizational principles, cell types, and functional properties. In flies, 22 types of lobula columnar neurons (LC) were described. Each LC is proposed to integrate a different behaviorally relevant visual feature. An anatomical property of LC neurons is the convergence of their axons onto cell-type specific target regions in the lateral protocerebrum called optic glomeruli. Previous work in Neohelice using Golgi impregnation revealed 29 types of LC projecting out of the lobula although their terminals were not described. Since Golgi is a stochastic technique the number of existing elements could be even greater. In this work we aimed to characterize the projection sites of LC in crabs using the massive staining of columnar cells applying dextran-conjugated dyes in the lobula. We also used Golgi impregnations and Bodians stainings to reveal the number, shape and location of optic glomeruli and gain further details about LC terminals.