Layer 5 and 6 auditory corticocollicular neurons are differentially distributed with respect to their subcortical targets in the mouse

Yudintsev, Georgiy; Llano, Daniel A.

Permalink

https://hdl.handle.net/2142/95193 Copy

Description

Title

Layer 5 and 6 auditory corticocollicular neurons are differentially distributed with respect to their subcortical targets in the mouse

Author(s)

• Yudintsev, Georgiy
• Llano, Daniel A.

Issue Date

2015-10-19

Keyword(s)

• Auditory cortex
• In vivo imaging
• Top-down projections
• Inferior colliculus

Abstract

The auditory corticocollicular projection has recently garnered much attention due to its ability to alter response properties of cells in the inferior colliculus. However, the basic anatomical organization of this pathway remains poorly understood. Corticocollicular neurons emanate from two distinct bands of the auditory cortex – layer 5 and deep layer 6 – and differ in their firing properties and cellular morphology. In addition, preliminary results from our laboratory in mouse demonstrate significant heterogeneity in the global distributions of layer 5 and 6 corticocollicular projections, with layer 6 cells spanning a broader region of the auditory cortex, extending more anteriorly and ventrally than layer 5, while layer 5 neurons are more concentrated in the primary auditory cortex, as confirmed by parvalbumin and SMI32 immunoreactivity. To further characterize the differences within the corticocollicular system, we ipsilaterally injected two retrograde tracers Cholera toxin B and Fluorogold into the inferior colliculus and the medial geniculate body, respectively. A subset of layer 5 corticothalamic neurons were also found to project to the inferior colliculus, while layer 6 corticocollicular neurons were found in a band that was distinct from layer 6 corticothalamic neurons. These data extend previous findings that suggest that layer 5 and layer 6 corticocollicular projections have different organizations and, presumably, different roles in modifying inferior colliculus function.

Type of Resource

• text
• image

Language

en

Permalink

http://hdl.handle.net/2142/95193

Sponsor(s)/Grant Number(s)

NIDCD R01 DC013073 02

Owning Collections