Cre driver mouse lines for thalamocortical circuit mapping.

Area of Science:

• Neuroscience
• Genetics
• Mouse Models

Background:

• Targeting specific neuronal subpopulations in mice is crucial for understanding brain function.
• Existing Cre driver lines lack sufficient specificity for thalamocortical (TC) neurons.

Purpose of the Study:

• To characterize novel Cre driver lines for selective targeting of dorsal thalamus nuclei, particularly TC neurons.
• To evaluate the utility of these lines for developmental and functional studies.

Main Methods:

• Characterization of Olig3-Cre, HDC-Cre, and CRH-Cre driver lines in mice.
• Analysis of Cre expression patterns using Cre-dependent reporter (CAG-tdTomato, Ai9).
• Optogenetic activation of TC afferents using channelrhodopsin-2 (Ai32) with HDC-Cre and CRH-Cre.

Main Results:

• Olig3-Cre shows broad thalamic expression, including TC neurons and interneurons.
• HDC-Cre and CRH-Cre exhibit unique, restricted expression patterns within TC neurons of sensory relay nuclei.
• All three lines demonstrate Cre expression by birth, suitable for developmental studies.
• Optogenetic activation of TC afferents revealed frequency-dependent depression in the visual cortex.

Conclusions:

• HDC-Cre and CRH-Cre lines provide selective targeting of TC neurons.
• These novel Cre driver lines are valuable tools for anatomical and functional studies of thalamocortical circuitry.
• The lines are suitable for investigating neural circuit development and function.