Piriform cortex and olfactory tubercle

Abstract

This chapter describes perspectives on the possible functional logic of neuronal circuits in the central olfactory system. The central olfactory system has multiplex pathways and loops that connect the olfactory bulb, olfactory cortex, neocortex, thalamus, ventral striatum, amygdala, hippocampus, and hypothalamus. Among the complex circuits, this chapter focuses on the possible functional differentiation of "olfactory bulb axon-Ib association axon (afferent) circuits" and "deep association axon (recurrent and top-down) circuits" in the piriform cortex. It is hypothesized that the activity of the former circuits is induced mainly by olfactory sensory inputs during the on-line inhalation phase of the sniff cycle, whereas activity of the latter circuits may occur mainly during the off-line exhalation phase. This chapter also discusses the possible function of motivation modules in the neuronal circuits of the olfactory tubercle.