In neonatal rodents, olfaction is already functional and more mature than the other senses. By silencing the outputs of olfactory bulb in the early postnatal days of mice, we found that the transient suppression of olfactory output led to a long-lasting reduction of oscillatory coupling in the downstream entorhinal-hippocampal networks and poor performance in cognitive tasks later in life, which is accompanied by dendritic sparsification of entorhinal pyramidal neurons. This indicates that olfaction early in life is necessary for cognitive development.
Olfactory bulb activity shapes the development of entorhinal-hippocampal coupling and associated cognitive abilities. Chen Y-N, Kostka JK, Bitzenhofer SH, Hanganu-Opatz IL (2023). Current Biology