Doctoral researcher working in Sehgal's lab, was interested in examining which neurons in the fly brain other than the clock cells might play a role in determining rhythms. Cavanaugh's results showed that the Pars Intercerebralis (PI), a group of neurons in the dorsal part of the fly brain, was required for maintaining rhythms (Cavanaugh et al. 2014). A polysynaptic circuit extends from central cl