Low nutritional state impairs novel object recognition memory in Drosophila

ALVAREZ PAULO AUGUSTO; MARIO RAFAEL PAGANI

Cordoba

Congreso; XXXIII CONGRESO ANUAL SAN 2018; 2018

Sociedad Argentina de Neurociencias

Specific behaviors are driven by specific motivational states, which in turn depend on a computation relating the internal state, the specific contexts and previous experiences. To examine how the brain processes environmental information in distinct internal states and its effects on learning, we adapted to Drosophila the novel object recognition (NOR) test, in which novelty, but not adverse stimuli, drives the behavior. The NOR test, widely used to study recognition memory in rodents, consists of three stages: habituation to the context, training and testing, across which different behavioral variables can be quantified. For this, we developed a device in which freely behaving flies can be recorded and subjected to thermo and optogenetics. First, we found that fruit flies habituate better to contexts with visual cues. The habituation response became a habituation memory only if flies were removed from the context. Then, we found that the behavior in well fed flies was normally driven by novelty and were capable of forming NOR memory. However, mild fasting eliminates recognition memory, but did not affect habituation or aversive olfactory conditioning memory. The effect of fasting on NOR memory was mimic by classic mutants with reduced insulin-like signaling. In addition to constitutive genetic manipulations, in this study we examined by acute thermogenetic manipulations the contribution of mushroom body neurons and neuromodulation to NOR memory.