Tullekit: integrated deep brain neural recording system for non-human primate models

The National Institute of Mental Health awarded Neuralthread Inc. $2.149 million on September 17, 2025, under the Mental Health Research Grants program (CFDA 93.242) to develop TULLEKIT, an integrated deep-brain neural recording system for non-human primates.

TULLEKIT combines ultraflexible 384-channel polymer probes, a minimally invasive port system for deep-brain implantation, and a wireless recording headstage to achieve stable, high-density neural recordings in freely moving subjects. The 45-millimeter probes incorporate on-board amplification and digitization, reducing device size while preserving biocompatibility. A refined robotic assembly process ensures reproducible fabrication of probe-shuttle assemblies. The platform features a scalable implant-ready port fixture, robotic stereotaxic actuation tools for precise probe insertion and retraction, and seamless integration with wireless data-logging capability. The system addresses tissue trauma, probe breakage, and chronic inflammatory responses that degrade long-term signal quality in existing tethered recording systems.

The project includes rigorous in vitro validation with mechanical stress testing and accelerated lifetime aging, followed by planned non-human primate studies in deep brain regions such as the hippocampus or striatum to assess device longevity and unit yield. The primary goal is to demonstrate stable recordings for up to one year, with groundwork laid for future expansions to up to 1,152 channels and additional functionalities including stimulation or imaging.

Performance occurs in San Francisco, California, with completion targeted for July 31, 2028. This is a Project Grant, the standard assistance type under the NIMH program.

Abstract

This grant application proposes a fully integrated solution, called tullekit, to achieve stable, high-density neural recordings in freely moving non-human primates (nhps). By uniting ultraflexible 384-channel probes, a minimally invasive port system for deep-brain implantation, and a wireless recording headstage, tullekit addresses key hurdles such as tissue trauma, probe breakage, and chronic inflammatory responses that degrade long-term signal quality. Its 45-MM-long polymer probes incorporate on-board amplification and digitization, reducing size and permitting dense insertion in deep structures without compromising biocompatibility. A refined robotic assembly process ensures reproducible fabrication of delicate probe-shuttle assemblies, minimizing error and streamlining production. The core innovation lies in an all-in-one platform featuring a scalable, implant-ready port fixture, robotic stereotaxic actuation tools for precise insertion and retraction, and seamless integration with a wireless data-logging headstage. This combination lowers surgical complexity, preserves recording stability over time, and alleviates behavioral constraints imposed by tethered systems. Rigorous in vitro validation-including mechanical stress tests and accelerated lifetime aging-precedes planned NHP studies that assess device longevity and unit yield in deep brain regions such as the hippocampus or striatum. The project's goal is to demonstrate stable recordings for up to one year, laying the groundwork for future expansions up to 1,152 channels or additional functionalities like stimulation or imaging. By merging robust fabrication techniques, novel shuttles, and an operator-friendly CO-developed pedestal and headstage design, tullekit stands to revolutionize chronic, large-scale electrophysiological research in nhps and beyond, paving the way for more effective diagnostics, fundamental research breakthroughs, and emerging neurotherapeutic technologies.