Fig. 10.

Spike and LFP recordings in the context of the known connectivity of the midbrain tectoisthmic circuit. The superficial layers receive direct visual input from retinal afferents (red), but no direct auditory input from primary auditory structures. LFP oscillations in the superficial layers were prominent in the low-gamma range, and synchronized bursts recorded in these layers included putative axonal inputs from neurons in the adjoining nucleus isthmi pars parvocellularis (Ipc, blue). Ipc neurons, in turn, receive visual and auditory input from layer 10 of the OT (black), and provide bursting input with low-gamma periodicity to the superficial layers. The OT also receives input from the adjoining cholinergic nucleus semiluminaris (SLu, blue).