Anatomical identification of primary auditory cortex in the developing gerbil

Cortical development is an active field of study. The gerbil provides an excellent model for research because at the moment of birth its brain is rather immature, anatomically and functionally. Furthermore, the gerbil auditory cortex is particularly amenable to investigation in that the gerbil’s onset of hearing occurs approximately after 14 days of postnatal life. Despite these advantages of the gerbil for auditory cortex development not much is known about the anatomy of the postnatal gerbil auditory cortex. For example, where is the gerbil auditory cortex? Prior to the onset of hearing, sounds cannot be used to localize auditory cortex. Therefore, the localization of the auditory cortex with anatomical landmarks alone during development is necessary. Anatomical and physiological approaches to localize the auditory cortex are published in the literature, but evaluated only in adult gerbils, and many of them are based on the fresh brain slice preparation and not applicable in vivo. The present study compares the anatomical references of the adult gerbil published in the literature with the anatomical references in the developing gerbil. Using specific blood vessel positions as landmarks, the position of the primary auditory cortex was estimated on fixed brains and in vivo. The lipophilic tracer Neurovue was used to confirm whether the position resulting from the anatomical analysis was consistent with the position of the auditory cortex.