Skip to main content
. Author manuscript; available in PMC: 2014 Jul 1.
Published in final edited form as: Brain Lang. 2012 Jun 23;126(1):22–28. doi: 10.1016/j.bandl.2012.05.004

Figure 1.

Figure 1

Thalamocortical connections mediating higher order auditory processing. Primary auditory cortex (AI) receives ascending information from the ventral division of the MGB (V) ending in layer 4, while the secondary auditory cortex (AII) receives information from the dorsal division of the MGB (D) (red thick lines). Feedforward corticothalamic projections from layer 5 (red thick lines) of AI establish a corticothalamocortical route for information transfer between AI and AII. In contrast, feedback corticothalamic projections from layer 6 of AI and AII are not primary conduits of information flow, but rather modulate thalamic activity in MGBv and MGBd, respectively (green dashed lines). Calbindin-expressing neurons in the medial division of the MGB (M) project widely to multiple cortical areas (black thin lines), targeting apical dendrites in layer 1 primarily. These projections have the potential to synchronize activity across broad cortical territories. Light grey shading (tonotopic nuclei and areas), dark grey shading (non-tonotopic nuclei and areas).