Study of the effect of visual stimuli on weak field electric fish Gymnotus carapo

• Grant number: 19/26178-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2020
• End date: November 30, 2020
• Field of knowledge: Biological Sciences - Biophysics - Biophysics of Processes and Systems
• Principal Investigator: Reynaldo Daniel Pinto
• Grantee: Beatriz Saiani Bellini
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Gymnotus carapo has an organ that generates electrical pulses (which propagate in the water around the animal) and an extensive electrical sensory system scattered throughout the body, both integrated into its nervous system, constituting an "electrical sense". Thus they are able to "see" an electrical image of their surroundings and establish a kind of electrical communication with their specifics. There is much work on the electrical sense of these animals but little is known about their other sensory modalities. They are known to be very sensitive to any kind of stimulus (visual, electrical, mechanical, etc.), reacting immediately with transient accelerations of the pulses of their electrical organ, which is called Novelty Response (NR).In this project we intend to build an experimental apparatus to produce simple visual stimuli. Color LEDs will be positioned to produce light pulses inside an aquarium where a photoreceptor will be installed to measure the light intensity that reaches the fish. The apparatus will capture and record the electrical pulses produced by the fish as it moves freely, as well as the intensity of light stimuli reaching the interior of the aquarium. We intend to use the NR as a tool to study the sensitivity of the visual system to color and light intensity. The light stimuli, always separated by long dark intervals, will be produced with the parameters color, duration and intensity following pre-established patterns. In data analysis, the occurrence of NR and its causal relationship with each stimulus will be used to infer whether or not it was perceived by the animal and to determine its sensitivity to the stimulus parameters. (AU)