Research Projects

Brain circuit mechanisms for associative memory
in Health and Disease


Associative memory is the most common but fundamental form of memory. The scent of your parents’ signature dish, for example, could be associated with sweet childhood memories and will vividly remind you of past events.

Impairments of associative memory function of the brain, on the other hand, directly lead to the disruption of our daily life, which affects >50 million Alzheimer’s disease patients worldwide. Identifying the circuit mechanisms underlying associative memory is not only a major goal for the basic systems neuroscience field, but also an ultimate goal for clinical neurology.


The Kei Igarashi laboratory at UC Irvine investigates:
(i) How our brain circuits enable associative memory in healthy animals?
(ii) How these circuits become impaired in Alzheimer’s disease? Can we restored the circuits?

To solve these problems, we are targeting the entorhinal-hippocampal circuits, using state-of-the-art systems neuroscience techniques:
– Optogenetic-assisted in vivo multi-unit spike and LFP recordings
– Olfactory-cued memory behavior tasks
– High-resolution functional anatomy




These works are supported by grants from the Whitehall Foundation, Alzheimer’s Association, Brain Research Foundation, Office of Naval Research, and Japan Science and Technology Agency.