Identification of a new brain cell important for object memory
Adrienne Kinman, working in the laboratory of Dr. Mark Cembrowski at the University of British Columbia, has identified a new type of brain cells, called ovoid neurons, and showed it responds specifically to novel, but not familiar objects. Named for the egg-like shape of their cell body, ovoid neurons can be found in the subiculum of the hippocampus, a brain region important for memory. In this publication, the researchers identified and characterized this previously undescribed excitatory neuron type and showed they were molecularly, anatomically, and functionally distinct from previously identified pyramidal neurons. Using a multiscale approach combining advanced brain imaging and manipulation techniques (including 100 days of longitudinal miniscope calcium imaging, transcriptomics, circuit mapping, electrophysiology, modeling, and optogenetics) the researcher showed that ovoid neurons form a dedicated channel for object-based novelty processing. Functionally, they display remarkably large and sustained responses to novel, but not familiar, objects, maintaining their novelty-selective signatures across weeks to months.
Manipulating ovoid-cell activity demonstrated their causal contribution to object memory. Optogenetic silencing during encoding abolished object-recognition memory, while activation drove animals toward familiar-object seeking. These optogenetic manipulations were able to toggle behavioural object preference based on the state of a single excitatory cell type while, remarkably, sparing spatial memory. In contrast, neighbouring pyramidal neurons showed no such specificity and instead largely supported spatial memory encoding and retrieval.
Scientific publication:
Adrienne I. Kinman, Derek N. Merryweather, Sarah R. Erwin, Regan E. Campbell, Kaitlin E. Sullivan, Larissa Kraus, Margarita Kapustina, Brianna N. Bristow, Mingjia Y. Zhang, Madeline W. Elder, Sydney C. Wood, Ali Tarik, Esther Kim, Joshua Tindall, William Daniels , Mehwish Anwer, Caiying Guo & Mark S. Cembrowski. Atypical hippocampal excitatory neurons express and govern object memory. Nature Communications 16, 1195 (2025). https://doi.org/10.1038/s41467-025-56260-8
