Kei M. Igarashi, Ph.D
Chancellor’s Fellow & Associate Professor
Department of Anatomy and Neurobiology, School of Medicine
University of California, Irvine

Circuit mechanisms of associative memory and its disruption in Alzheimer’s disease

Memory has multiple components: “what” memory (item/object), “when” memory (time) and “where” memory (space). Research in the past decades revealed neurons involved in spatial memory, including place cells in the hippocampus and grid cells in the medial entorhinal cortex (MEC). However, circuit mechanisms of memory about time and item/object remain largely unclear. Our lab focuses on identifying mechanisms for item/object memory, and how these circuits become impaired in the disease of memory – Alzheimer’s disease. We previously reported that neurons in the lateral entorhinal cortex (LEC) are involved in odor object-reward associative learning (Igarashi et al., 2014), and recently found that the encoding of odor-reward association in LEC neurons are controlled by dopamine signals from the VTA (Lee et al., Nature, 2021). I would like to follow up with our recent work on output layers of the LEC (layer 5/6) and their major target, the medial prefrontal cortex. In the second part of the talk, I will share our results on the loss of place cell and grid cell activities (Jun et al., Neuron 2020), and impairment of dopamine activity in the LEC of Alzheimer’s disease mouse model.

Faculty Host: Jim Knierim