Temporal processing in Drosophila melanogaster

Descrizione del progetto

Elaborazione temporale delle informazioni nel cervello

Per elaborare le informazioni, il cervello si basa su modelli spaziali e temporali dell’attività elettrica; mentre quelli del primo tipo sono dettati dall’anatomia del cervello, i meccanismi che regolano le dinamiche temporali dell’attività nell’arco di millisecondi o minuti sono tuttora poco compresi. Il progetto TEMPRODROME, finanziato dal CER, studierà questi meccanismi impiegando come organismo modello il moscerino della frutta Drosophila melanogaster. I ricercatori utilizzeranno registrazioni patch-clamp in vivo, imaging funzionale ed esperimenti comportamentali allo scopo di studiare il modo in cui il cervello filtra e memorizza le informazioni sugli stimoli visivi nel corso del tempo, come raccoglie le informazioni sul movimento visivo e le modalità attraverso cui tiene traccia della distanza percorsa nel tempo durante il movimento.

Obiettivo

All information processing in nervous systems relies on spatial and temporal patterns of neural activity. While spatial patterns are dictated by neuroanatomy, the mechanisms that give rise to temporal activity patterns are diverse. They range from fast voltage dynamics of single neurons at one end of the spectrum to slow transcriptional and structural changes at the other, but the rules that shape signals at timescales in between milliseconds and minutes are poorly understood. The proposed research aims to uncover mechanisms of temporal information processing at these intermediate timescales, at which temporal patterns are thought to emerge from recurrently connected circuits. Detailed insight into the function of these circuits has been limited by the large number of circuit elements, by the lack of knowledge about their connectivity, and by the impracticability of recording from all circuit elements under naturalistic conditions. In Drosophila melanogaster, these limitations no longer apply. The comparatively low number of neurons, their well-mapped connectivity, and our ability to record and control their activities make mechanistic concepts testable. We will focus on three processes in the brain of Drosophila that unfold over three timescales ranging from milliseconds to minutes: 1) temporal filtering in the motion vision system, 2) sequential sampling of motion information in the lead-up to a perceptual judgement, and 3) temporal integration of distance during locomotion. Patch clamp experiments in the smallest of invertebrate neurons in vivo will allow us to record activity at the highest temporal resolution. We will combine this technique with behavioural, genetic, and imaging experiments to test the roles of individual neurons, their biophysical properties, and their synaptic connections in processing signals at intermediate timescales. The proposed experiments will further our understanding of motion vision, perceptual decision-making, and path integration.