As novel sights become familiar, different brain rhythms, neurons take over

PV neurons are known to produce high frequency gamma rhythms in the cortex. Gamma rhythms give way to lower frequency beta rhythms and the activity of PV neurons dies out in favor of a rise in activity by inhibitory somatostatin (SOM) expressing neurons. In parallel experiments, they engineered some mice so that their PV or SOM neurons would flash brightly when active. PV neurons responded strongly to images when they were novel but that activity became replaced by increasing SOM activity over several days as the image became familiar. SOM neurons are believed to suppress PV neurons, Bear said, but to prove that SOM inhibition of PV accounts for visual recognition memory, the lab still needs to perform more experiments.