Neural Circuits and Systems Neuroscience
Author: Maria Grazia Lepore | email: lepore.mgrazia@gmail.com
Maria Grazia Lepore 1°, Daniel Tomsic 1°, Julieta Sztarker 1°
1° Instituto de Fisiología, BiologíaMolecular y Neurociencias (IFIBYNE), UBA-CONICET, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina. Departamento de Fisiología, Biología Molecular y Celular Dr HéctorMaldonado, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
Vision is essential for animals as it allows them to acquire, process and transform visual information to build an internal representation of the environment and to select appropriate behavioral responses. The semiterrestrial crab Neohelice granulata possesses a highly developed visual system and displays conspicuous visually guided behaviors. The brain structures that processes visual information are called optic neuropils. Here, we present the first anatomical study of individual columnar elements composing the third optic neuropil, the lobula. This is involved in motion processing, binocular and multimodal integration and learning-induced plasticity. Using Golgi staining and camera lucida reconstructions, we characterized 140 types of elements, including input, translobular, centrifugal, and input columnar elements, each of them morphologically distinct in the distribution of their arborizations, their size, and shape. In the present work, we divided the lobula into 13 layers to separate the arborization patterns seen in the reconstructed elements together with available descriptions of tangential layers in the lobula. Our results reveal a complex and dense neuropil presenting many synaptic layers and an important number of lobula columnar neurons that could encode behaviorally relevant visual features. We analyze and discuss our findings considering the similarities and differences found between the layered organization and components of crustacean and insect lobul.