7/
We also tested blind mice with bilateral ablation of olfactory sensory neurons on the task.

And as expected, their performance tanked!

6/
Interestingly, during rewarded trials, mice with one nostril blocked adopted a "hunting" strategy: scanning until they randomly hit the target, then used self-motion cues to secure extra rewards. However, once they strayed too far, they were unable to relocate the target.

5/
However, blind mice with one nostril blocked struggled, and often waited at random angles. This breakdown was pronounced in probe trials.

4/
Blind control mice quickly mastered the task and maintained their head at the correct target angle even during unrewarded probe trials.

3/
We then asked: if HD signals deteriorate after disrupting stereo olfaction, do HD-related behaviors suffer as well? To test this, we designed a closed-loop task where mice received brain stimulation as reward for keeping their head at a specific allocentric angle for 500 ms.

2/
Could the loss of tuning simply be stemming from reduced odor input due to sealing one nostril? To address this possibility, we employed an alternative method to disrupt stereo odor processing. Again, HD tuning was impaired.

1/
Many organisms, incl. rodents, use stereo olfaction to pinpoint odor direction. This prompted us to ask if our blind mice were using this mechanism to fine-tune their HD system. To test this, we sealed one nostril & recorded from HD cells. The result? HD cells became unstable!