Professor Ben de Bivort (Harvard): 'The neurobiology of zombie flies' School of Psychology and Neuroscience Seminar

Our first Friday Seminar of the semester will be by Professor Ben de Bivort (Harvard) on ‘The neurobiology of zombie flies: mechanisms of parasite host-manipulation', hosted by Eleonora Gagliardi. The seminar will be a hybrid presentation hosted online and in the Seminar Room for us all to get together.

For at least two centuries, scientists have been enthralled by the “zombie” behaviours induced by mind-controlling parasites. Despite this interest, the mechanistic bases of these uncanny processes have remained mostly a mystery. In their research, Professor de Bivort group leveraged the Entomophthora muscae-Drosophila melanogaster ‘zombie fly' system to reveal the molecular and cellular underpinnings of summit disease, a manipulated behaviour evoked by many fungal parasites. Using high-throughput behaviour assays to measure summiting, they discovered that summiting behaviour is characterised by a burst of locomotion and requires the host circadian and neurosecretory systems, specifically DN1p circadian neurons, pars intercerebralis to corpora allata projecting (PI-CA) neurons and corpora allata (CA), the sole site of juvenile hormone (JH) synthesis and release.

The blood-brain barrier of flies late in their infection was significantly permeabilized, suggesting that factors in the hemolymph may have greater access to the central nervous system during summiting. Metabolomic analysis of hemolymph from summiting flies revealed differential abundance of several compounds compared to non-summiting flies. Transfusing the hemolymph of summiting flies into non-summiting recipients induced a burst of locomotion, demonstrating that factor(s) in the hemolymph likely cause summiting behaviour.

Altogether, the work reveals a neuro-mechanistic model for summiting wherein fungal cells perturb the fly's hemolymph, activating the neurohormonal pathway linking clock neurons to juvenile hormone production in the CA, ultimately inducing locomotor activity in their host.