138 | IMPLEMENTATION OF THE AUTOMATIZED INTERVAL-TIMING EXPERIMENTAL SETUP AND EXPLORATION OF MUSHROOM BODIES INVOLVEMENT IN TIME-REFERENCE MEMORY

Cognition, Behavior, and Memory

Author: Canela Pedreira González | Email: canelaghia@gmail.com


Canela Pedreira González , Malena Cortasa , Lia Frenkel

1° Laboratorio Neurociencias del Tiempo, iB3, Instituto de Biociencias, Biotecnología y Biología traslacional, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires

The neurobiological basis of time estimation has not been clearly established yet. One possibility is that It encloses cognitive processes such as attention and/or working memory. We hypothesise that time estimation could be a type of immediate/short-term memory in which time itself is the stimulus that launches a behaviour. We first developed a manual setup for the study of a time-referenced memory in flies based on the proboscis extension response (PER) to a sucrose solution. When analysing the last PER for each interval, we found that a 9-trials fixed-interval training significantly increases the time until last-PER (from 32.53±3.29s to 50,83±1.49s), which results in almost a 10s anticipation of sucrose appearance. Here we show the development of an automatized interval-timing experimental setup for Drosophila melanogaster in which the isolated fly is presented at a fixed or variable interval with a sucrose drop that is only available for 10s. Moreover, we show the implementation of DeepLabCut software to track proboscis position over time and automatically analyse it. In addition, we study the necessity of mushroom bodies (MB) processing for this time-reference memory. We introduce some experiments where we can reversibly deplete synaptic vesicles specifically in the MB by keeping the flies at high temperature. We also rule out whether differences among groups could be due to alterations in general responsiveness.