Topography of corticothalamic projections from the auditory cortex of the rat

  • Hazama M
  • Kimura A
  • Donishi T
 et al. 
  • 50


    Mendeley users who have this article in their library.
  • 33


    Citations of this article.


Corticothalamic projections from cortical auditory field to the medial geniculate body (MG) in the rat were systematically examined by making small injections of biocytin in cortical area Te1. All injections, confined to 400 μm in diameter, resulted in two projections terminating in the ventral (MGV) and dorsal divisions (MGD) of the MG. The projections to the MGV were evidently topographic. The rostral and caudal portions of area Te1 projected to the ventromedial and dorsolateral parts of the MGV, respectively, forming narrow bands of terminal axons that extended in the mediolateral direction in the coronal plane of the MGV. The minimum dorsoventral width of the bands ranged approximately from 100 to 300 μm. Besides, the more rostral portion of area Te1 tended to project to the more rostral side of the MGV. The projections to the MGD consistently arborized in its ventral margin made up of the deep dorsal nucleus of the MGD. A similar weak topography along the rostrocaudal direction was observed in the projections to the MGD. Large terminals were occasionally found in the MGD after the injections involving cortical layer V. The distribution of large terminals also appeared topographic along with small terminals that were the major component of labeling. Collaterals of labeled axons produced slabs of terminal field in the thalamic reticular nucleus, which also exhibited a weak topography of distribution. These results provide insights into the structural basis of corticofugal modulations related to the tonotopic organizations in the cortex and MG. © 2004 IBRO. Published by Elsevier Ltd. All rights reserved.

Author-supplied keywords

  • Area Te1
  • Biocytin
  • Corticofugal projection
  • Giant terminal
  • Thalamic reticular nucleus
  • Tonotopic organization

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free