title: Dual compartments of the ventral division of the medial geniculate body projecting to the core region of the auditory cortex in C57BL/6 mice.
abstract: We investigated precise projection patterns from the ventral division of the medial geniculate body (MGv) projecting to the core region of the auditory cortex in C57BL/6 mice. The core region in mice comprises two different tonotopically organized areas, the anterior auditory field (AAF) and the primary auditory cortex (AI). In the present study, AAF and AI were functionally identified using flavoprotein fluorescence imaging. Biotinylated dextran amine (BDA) was injected iontophoretically into the tonotopic bands to 5kHz and 20kHz in AAF, and those to 5kHz, 10kHz, and 20kHz in AI for staining MGv neurons projecting to the injected sites. MGv neurons projecting to AAF were found in the medial part of MGv, while MGv neurons projecting to AI were found in the lateral part. In the medial part of MGv, areas projecting to 5-20kHz bands in AAF were aligned along the medio lateral axis. In the lateral part of MGv, areas projecting to 5-20kHz bands in AI were aligned along the dorso ventral axis. These results indicate that AAF and AI receive auditory information via two different MGv compartments with independent tonotopic axes, respectively.
authors.affiliation: Division of Neurobiology and Anatomy, Graduate School of Medicine and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata 951-8510, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Horie
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tsukano
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Hishida
authors.forename: Hirohide
authors.initials: H
authors.lastname: Takebayashi
authors.forename: Katsuei
authors.initials: K
authors.lastname: Shibuki
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D001303:Auditory Cortex / Q000166:cytology / Q000502:physiology*; D001306:Auditory Pathways / Q000502:physiology; D005829:Geniculate Bodies / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000166:cytology; D013788:Thalamus / Q000166:cytology / Q000502:physiology*
keywords: Anterior auditory field; C57BL/6 mice; Dual compartments; Parallel pathway; Primary auditory cortex; Ventral division of the medial geniculate body