Stereotactic system for accurately targeting deep brain structures in awake head-fixed mice

Area of Science:

• Neuroscience
• Neurophysiology
• Surgical Instrumentation

Background:

• Deep brain nuclei like the amygdala are vital for cognition and behavior.
• Accurate electrophysiological recordings in awake, head-fixed rodents are challenging due to limitations in stereotactic accuracy.

Purpose of the Study:

• To develop and validate a system for precise stereotactic targeting of deep brain structures in awake, head-fixed rodents.
• To enable accurate placement of recording electrodes and other probes for studying brain function.

Main Methods:

• Designed and implemented the DeepTarget system for stereotactic head fixation and recording.
• Validated the system using intracellular recordings from optogenetically tagged amygdalar neurons.
• Performed histological reconstruction to assess targeting accuracy and precision.

Main Results:

• The DeepTarget system demonstrated accuracy and precision within approximately 100 μm.
• Successfully targeted deep brain structures including the amygdala, mammillothalamic tract, and subthalamic nucleus.
• Enabled intracellular recordings from specific neuronal populations in awake mice.

Conclusions:

• The DeepTarget system overcomes previous challenges in stereotactic targeting for electrophysiological recordings in awake rodents.
• This approach significantly improves the accuracy and precision of probe placement in the brain.
• The system is adaptable for various probes and brain targets, advancing research in neuroscience.