Auditory projections from the IC to the SCN by way of the LG in the mole, Mogera

Abstract

To study morphological substrates for sensory specialization in subterranean mammals, we investigated both auditory and visual pathways in the mole. The inferior colliculus (IC), an auditory relay, projects not only to the medial geniculate, the major gateway to the auditory cortex, but also to the lateral geniculate (LG), the major gateway to visual cortex. Further evidence is that the LG does not send many fibers to the cortex in the mole. Instead, the auditory inputs to the LG are likely to be conveyed to the suprachiasmatic hypothalamic nucleus (SCN), which plays a role in photoperiodic functions in common mammals. Auditory inputs to the SCN may subserve periodic reproductive behaviors in the exclusively separated territorial domains of subterranean mammals.