  Recent research has revealed the unique functionality of cortical pyramidal
cell subtypes, namely intratelencephalic neurons (IT) and pyramidal-tract
neurons (PT). How these two populations interact with each other to fulfill
their functional roles remains poorly understood. We propose the existence of a
functional hierarchy between IT and PT due to their unidirectional connection
and distinct roles in sensory discrimination and motor tasks. To investigate
this hypothesis, we conducted a literature review of recent studies that
explored the properties and functionalities of IT and PT, including causal
lesion studies, population-based encoding, and calcium imaging experiments.
Further, we suggest future experiments to determine the relevance of the
canonical IT-PT circuit motif for temporal processing. Our work provides a
novel perspective on the mechanistic role of IT and PT in temporal processing.
