A new study published in Nature, “Stereo olfaction underlies stable coding of head direction in blind mice,” led by Dr. Stuart Trenholm, with key contributions from Kadjita Asumbisa and Adrien Peyrache, reveals that mice without vision rely on stereo olfaction – the difference in scent between their two nostrils – to maintain a stable sense of spatial orientation.
Using NeuroNexus Buz32 and Buz64 multi-shank silicon microelectrode arrays, the team recorded head direction (HD) cells in the anterior dorsal nucleus (ADn) of the thalamus. They found that impairing stereo olfaction, by blocking one nostril or merging airflow between nostrils, significantly disrupted HD cell tuning, causing animals to lose their internal compass.
Furthermore, behavioral assays showed that blind mice with disrupted stereo olfaction struggled to maintain head direction awareness, confirming that olfactory-based spatial coding is critical for navigation in the absence of vision.