Sharp wave ripples

Researchers at the New York University School of Medicine reported…that they had improved the memory of lab animals by tinkering with the length of a dynamic signal in their brains… The feat is exciting in its own right, with the potential to enhance recall in people someday, too. 

But it also points to a more comprehensive way of thinking about memory, and it identifies an important clue, rooted in the duration of a neural event, that could pave the way to a greater understanding of how memory works.

Since the 1980s, scientists have been tuning in to short bursts of synchronized neural activity in the brain area called the hippocampus. The activity consists of complex, cascading electrical patterns that, when recorded, “sound like an explosion,” said Shantanu Jadhav, a neuroscientist at Brandeis University. 

Since their discovery, these sharp wave ripples have been associated with memory because they arise when neurons suddenly replicate their prior firing patterns in an accelerated surge, as if quickly replaying snippets of a previous experience. They do so when an animal is asleep, presumably to consolidate newly gained knowledge for long-term storage.