A neural device to restore memory

Intended to help military service members with traumatic brain injury (TBI), but could also help with Alzheimer's disease and epilepsy
July 11, 2014

Lawrence Livermore National Laboratory (LLNL) will develop an implantable neural device with the ability to record and stimulate neurons within the brain to help restore memory (credit: LLNL)

The Defense Advanced Research Projects Agency (DARPA) has awarded Lawrence Livermore National Laboratory (LLNL) up to $2.5 million to develop an implantable neural device with the ability to record and stimulate neurons within the brain to help restore memory.

DARPA’s interest is in traumatic brain injury (TBI), which disrupts memory. DARPA says TBI has affected 270,000 military service members since 2000. It could also help with Alzheimer’s disease and epilepsy.

LLNL’s Neural Technology group, in collaboration with the University of California, Los Angeles (UCLA) and Medtronic, hopes to develop an implantable neural device that can restore individuals’ ability to form new memories and access previously formed ones.

How it will work

The device will be a neuromodulation system — a sophisticated electronics system to modulate (control) neurons, with real-time recording and closed-loop stimulation of neural tissues to bridge gaps in the injured brain and to understand how new memories are formed.

Artist’s impression of a neural stimulator/recorder wireless device being developed by LLNL (credit: LLNL)

This will be a miniature, wireless, implantable neural device to be implanted into the hippocampus (plays an important role in the formation of new memories) and the entorhinal cortex (the main interface between the hippocampus and neocortex). The device will be a closed-loop system that will stimulate and record 64 channels located on two high-density electrode arrays, with single- neuron and local-field-potential recordings.

The arrays will connect to an implantable electronics package capable of wireless data and power telemetry. An external electronic system worn around the ear will store digital information associated with memory storage and retrieval and provide power telemetry to the implantable package using a custom RF-coil system (similar to a cochlear implant).

Lawrence Livermore National Laboratory | This neural implant is
designed to be implanted in the human central and nervous systems

The team’s goal is clinical testing by UCLA by 2017, using a device fabricated by Medtronic.

“Currently, there is no effective treatment for memory loss resulting from conditions like TBI,” said LLNL’s project leader Satinderpall Pannu, director of the LLNL’s Center for Bioengineering, a unique facility dedicated to fabricating biocompatible neural interfaces.

“The RAM program poses a formidable challenge reaching across multiple disciplines from basic brain research to medicine, computing and engineering,” said Itzhak Fried, lead investigator for the UCLA on this project and  professor of neurosurgery and psychiatry and biobehavioral sciences at the David Geffen School of Medicine at UCLA and the Semel Institute for Neuroscience and Human Behavior. “But at the end of the day, it is the suffering individual, whether an injured member of the armed forces or a patient with Alzheimer’s disease, who is at the center of our thoughts and efforts.”

LLNL’s work on the Restoring Active Memory program supports President Obama’s Brain Research through Advancing Innovative Neurotechnologies (BRAIN) initiative. The research is funded by DARPA’s Restoring Active Memory (RAM) program*.

* The end goal of RAM is to develop and test a wireless, fully implantable neural-interface medical device for human clinical use, but a number of significant advances will be targeted on the way to achieving that goal.

To start, DARPA will support the development of multi-scale computational models with high spatial and temporal resolution that describe how neurons code declarative memories—those well-defined parcels of knowledge that can be consciously recalled and described in words, such as events, times, and places.

Researchers will also explore new methods for analysis and decoding of neural signals to understand how targeted stimulation might be applied to help the brain reestablish an ability to encode new memories following brain injury. “Encoding” refers to the process by which newly learned information is attended to and processed by the brain when first encountered.

Building on this foundational work, researchers will attempt to integrate the computational models developed under RAM into new, implantable, closed-loop systems able to deliver targeted neural stimulation that may ultimately help restore memory function. These studies will involve volunteers living with deficits in the encoding and/or retrieval of declarative memories and/or volunteers undergoing neurosurgery for other neurological conditions.

In addition to human clinical efforts, RAM will support animal studies to advance the state-of-the-art of quantitative models that account for the encoding and retrieval of complex memories and memory attributes, including their hierarchical associations with one another. This work will also seek to identify any characteristic neural and behavioral correlates of memories facilitated by therapeutic devices.

Restoring Active Memory (RAM)