This video demonstrates the design of a custom implant system, the Head Adjustment Tool (HAT), for head-restrained neural recordings in mice. The system comprises three key components:

Head Frame: A robust and biocompatible frame designed to be implanted on the skull using adhesive cement. The frame includes external slots for clamping, ensuring secure head restraint during experimental procedures. Printed in a durable material, the frame maintains structural integrity over extended use and has been tested for four months on four mice with no issues.

Helmet: A protective cover that clips onto the frame and is secured with two M1 screws, one at the front (rostral side) and one at the back (caudal side). Constructed from a flexible yet tough resin, the helmet withstands potential damage from cage activities and prevents exposure to the implanted area. This feature protects the surgical site and brain implants during recovery and between experimental sessions, and it can be in contact with the skin of cage mates without causing irritation.

Docking System: Designed to interface seamlessly with motorized stages for precise alignment, the head frame allows repeatable targeting of brain structures. The system facilitates precise craniotomy and probe insertion while maintaining the animal’s stability during imaging or recording sessions (not shown in the video).

The HAT implant design provides robust protection for the skull and implant, ensuring long-term usability and animal welfare. By combining precision engineering with practical animal care considerations, this system supports high-quality neuroscience research.