Thalamic connections of the auditory cortex in marmoset monkeys: Core and medial belt regions
Article first published online: 9 MAR 2006
Copyright © 2006 Wiley-Liss, Inc.
Journal of Comparative Neurology
Volume 496, Issue 1, pages 72–96, 1 May 2006
How to Cite
De La Mothe, L. A., Blumell, S., Kajikawa, Y. and Hackett, T. A. (2006), Thalamic connections of the auditory cortex in marmoset monkeys: Core and medial belt regions. J. Comp. Neurol., 496: 72–96. doi: 10.1002/cne.20924
- Issue published online: 9 MAR 2006
- Article first published online: 9 MAR 2006
- Manuscript Accepted: 4 NOV 2005
- Manuscript Revised: 11 SEP 2005
- Manuscript Received: 10 JUL 2005
- National Institutes of Health/National Institute on Deafness and other Communications Disorders. Grant Number: R01 04318
In this study and its companion, the cortical and subcortical connections of the medial belt region of the marmoset monkey auditory cortex were compared with the core region. The main objective was to document anatomical features that account for functional differences observed between areas. Injections of retrograde and bi-directional anatomical tracers targeted two core areas (A1 and R), and two medial belt areas (rostromedial [RM] and caudomedial [CM]). Topographically distinct patterns of connections were revealed among subdivisions of the medial geniculate complex (MGC) and multisensory thalamic nuclei, including the suprageniculate (Sg), limitans (Lim), medial pulvinar (PM), and posterior nucleus (Po). The dominant thalamic projection to the CM was the anterior dorsal division (MGad) of the MGC, whereas the posterior dorsal division (MGpd) targeted RM. CM also had substantial input from multisensory nuclei, especially the magnocellular division (MGm) of the MGC. RM had weak multisensory connections. Corticotectal projections of both RM and CM targeted the dorsomedial quadrant of the inferior colliculus, whereas the CM projection also included a pericentral extension around the ventromedial and lateral portion of the central nucleus. Areas A1 and R were characterized by focal topographic connections within the ventral division (MGv) of the MGC, reflecting the tonotopic organization of both core areas. The results indicate that parallel subcortical pathways target the core and medial belt regions and that RM and CM represent functionally distinct areas within the medial belt auditory cortex. J. Comp. Neurol. 496:72–96, 2006. © 2006 Wiley-Liss, Inc.