Title: Social Isolation's Lifespan Cascade: Linking Early Compensatory Hyperactivity to Late-Life Cognitive Decline and Alzheimer's Risk

Poster Number: #1580

Authors: Gierke, C., Morales, M., Palisson, T.M., Díaz-Gierke, W., Navarro, C.F., Diaz, R., Valderrama, A., Pizarro, M., Palma, J., Iturriaga, V., & Francisco del Pino

Abstract / Poster Summary

Background: Apathy and motivational deficits are hallmark symptoms of neurodegenerative disorders, yet their developmental origins remain poorly understood. Using Drosophila melanogaster as a powerful comparative model, this study explores how early-life social experience shapes motivational traits and neural circuit programming across the lifespan to influence long-term Alzheimer's disease (AD) risk.

Methods: Informed by human data from a Chilean cohort , social environments were experimentally manipulated during early development in Drosophila. Feeding, locomotor, and exploratory behaviors were longitudinally tracked from larval stages through adulthood. Larval feeding motivation was evaluated via mandibular retractions in a 5-minute assay at 96 hours , and adult hyperlocomotion was assessed via exploration in a novel environment under food deprivation at 7 days.

Results: Counter to traditional hypotheses, early-life social isolation induced a phenotype of persistent compensatory motivational hyperactivity. Socially isolated third-instar larvae exhibited a +17% increase in feeding activity compared to socially reared controls (62 vs. 53 retractions). This behavioral drive persisted into adulthood, where 7-day-old isolated flies showed a +25% increase in locomotor exploration under food deprivation.

Email: christinegierke@uchile.cl | fdelpino@med.uchile.cl