On and off visual channels adapt differentially to object motion allowing arthropods to recognize novel stimuli occurrence

LUCCA SALOMÓN; PEREZ SCHUSTER VERONICA; GABRIELA HERMITTE; BERON DE ASTRADA, MARTIN

Córdoba

Congreso; Congreso Argentino de Neurociencias, 2018; 2018

Sociedad Argentina de Neurociencias

Object motion detection provides essential cues for a wide variety of behaviors such as mate, prey, or predator detection. In insects and decapod crustaceans, encoding of object motion is associated to visual processing in the third retinotopic optic neuropil, the lobula. Due to the thin caliber of the small-field lobula columnar neurons, almost all we know about object motion detection arises from studies on their postsynaptic and larger lobula output neurons. Here we used calcium imaging to study the activity of the columnar neurons that feed onto the crab?s lobula when stimulated by object motion stimuli that varied in contrast polarity. Dark edges translating over clear backgrounds evoked more powerful responses than stimuli with the opposite contrast relation. Besides, columnar neurons that were habituated to edge motion with certain contrast polarity recovered when stimulated with the opposite one. As lobula output neurons have been implicated in driving alert and defensive responses, we also studied the modulation of the crab cardiac activity (a variable indicative of animal internal state) to variations in the same visual parameters. We found a high correlation between the activity of the columnar neurons and changes in cardiac activity. These results are consistent with the involvement of the lobula in object motion coding. Moreover, the differential adaptation observed for the on and off visual channels allows arthropods to recognize novel visual stimuli.