Meeting Abstract
Task performance in social insects is governed by the interplay between ecological and social factors that influence task demand and regulated by neurobiological mechanisms. Workers of the ant Pheidole dentata develop their pluripotent and flexible task repertoire over the first few weeks of adult life in concert with a suite of physiological, neuroanatomical, and neurochemical changes. Our current research probes the limits of nervous system miniaturization and behavioral flexibility in P. dentata workers by impairing olfaction, their primary sensory modality, through ablation of one antenna. Using age-matched worker cohorts and multiple behavioral and neurobiological assays, we demonstrate remarkable resilience following reduction in the size of an already miniaturized nervous system. Unilateral ablation results in a 25% reduction in the volume of the primary olfactory input region of the brain, but increased expression of synaptic vesicle proteins in ipsilateral higher-order areas, potentially reflecting compensation in olfactory circuits. Worker task performance is largely preserved after our experimental injury: only pheromone trail-following is impaired, and preliminary evidence suggests that workers that sustain injuries earlier in life may regain some trail-following ability. Injured ants leave the nest sooner, engage in riskier behaviors such as foraging and aggressive interactions, and have increased levels of biogenic amine neuromodulators in their brains relative to same-aged, non-injured nestmates. Our results suggest that despite their minute brains, ants can compensate for significant sensory deficits and continue to effectively contribute to colony labor needs.
