Cedars-Sinai researchers have made a breakthrough in understanding how brain cells responsible for working memory coordinate intentional focus and short-term storage of information. This study, published in Nature, identified a group of neurons influenced by brain waves that play a crucial role in the storage of short-term memories. Working memory, which involves storing information for moments at a time, requires continued focus to be maintained and can be impacted by various diseases and conditions such as Alzheimer’s disease and attention-deficit hyperactivity disorder.
By recording brain activity in 36 hospitalized patients with electrodes implanted in their brains, the researchers explored how working memory functions. Patients were shown photos on a computer screen and then asked to remember them after a brief blank interval. When patients responded quickly and accurately, two groups of neurons were observed firing: “category” neurons that respond to the photo categories shown, such as animals, and PAC neurons. PAC neurons use phase-amplitude coupling to coordinate with category neurons and enhance the ability to recall information stored in working memory by firing in time with the brain’s theta and gamma waves.
The PAC neurons work in the hippocampus, a region of the brain typically associated with long-term memory, showing for the first time that the hippocampus also plays a role in controlling working memory. This research was part of a consortium funded by the NIH’s BRAIN Initiative and involved pooling data from multiple institutions to create a statistically powerful study that a single institution could not have accomplished alone. By leveraging innovative technologies and collaboration across institutions, the Rutishauser Lab is shedding light on how neurons support memory storage in the brain, which could have implications for understanding and potentially treating conditions like Alzheimer’s disease and other dementias.
This discovery provides a deeper understanding of how the brain maintains and controls working memory, which is essential for tasks requiring short-term retention of information, such as remembering a phone number or following a set of instructions. The coordination between category neurons and PAC neurons, facilitated by phase-amplitude coupling, enables the brain to focus on and retain memories once they are formed. This research also highlights the importance of the hippocampus in working memory, challenging previous perceptions of its role primarily in long-term memory.
By linking brain waves, neuron activity, and memory storage in a novel way, this study offers a new perspective on how the brain processes information and maintains working memory. Understanding the control aspect of working memory is crucial for developing treatments for neurological conditions that affect memory retention and focus, such as Alzheimer’s disease and ADHD. Leveraging advanced technologies and collaboration through initiatives like the BRAIN Initiative, researchers are making significant strides in unraveling the complex mechanisms underlying memory storage and cognitive function, with implications for improving treatment strategies for a range of neurological disorders.
