Preprint: Cytoarchitecture and Myeloarchitecture of the sheep (Ovis aries) auditory cortex

An updated version of this preprint has now been published open access in the Journal of Anatomy

Abstract

The auditory cortex is central to auditory perception, but its detailed structural and functional organization in sheep (Ovis aries) has not been thoroughly investigated. In this study, we sought to address this gap by providing an in-depth overview of the cytoarchitecture and myeloarchitecture of the sheep auditory cortex, using cresyl violet staining and the neurochemical markers myelin basic protein and parvalbumin. Tissue samples from four sheep were used to characterize cortical layers, cellular composition, and myelination patterns, revealing a six-layered organization with variations in cell density and distribution. Myelin basic protein staining highlighted myelinated regions, providing insights into the myeloarchitecture, while parvalbumin staining identified the distribution of GABAergic interneurons, providing indications of the potential location of the primary auditory cortex. These findings deepen our knowledge of the auditory cortex in sheep, a key model for investigating sensory processing in large mammals. The structural and functional organization of the ovine auditory cortex aligns with findings in other mammals, suggesting that both are conserved across species and supporting the idea of evolutionary conservation in auditory processing mechanisms. However, future functional studies, using auditory stimulation paradigms, are necessary to fully understand the functional organization of this important sensory region.