Who can see your viewing activity?
Q: All those landmarks are visual?
Max - yes in these conditions
Q - Is the fluctuation in Ca2+ activity in both ellipsoid body and protocerebral bridge simultaneous or is there a time delay?
Is the phase in reference to the head position of the fly to a given landmark?
Q: What about the up-down directions?
Thank you for sharing this spectacular story with us. Do we know how the fly’s velocity is encoded in the central complex? Do we know if the fly’s traveling velocity modulate the amplitude of the d7/PFN sinusoids?
Kate Otter [she/her]
Given the visual ring inputs to the ellipsoid body, this circuit and these computations seem specific to visual navigation, in the case of a fly born blind do you think this circuit could be co-opted by another sensory system? Would you predict that a similar architecture would exist to do these computations for other navigational systems (auditory/olfactory, etc.)?
Do flies have a 45 degree quantization of the world?
Great developmental question Kate
Wonderful talk! Certain insects perform path integration in the dark. Since the visual motion signal enters the system through the PFNs would you expect the travelling direction signal to persist in these insects? Or would you expect them to get a signal from a different modality (wind direction maybe?)
Thank you, wonderful talk. Question: Apologies if I missed this, but how old were the flies used in the experiments and when does the ellipsoid body and protocerebral bridge finishing developing?
@kate I believe it can also track wind direction, from another set of wind direction ring neurons
Besides velocity, were there any other types of information you expected to be represented in this circuit that did not appear?
How do you believe these findings correspond to human navigation? What do you think the major similarities/differences would be?
There are many times when different streams of sensory information will hold more/less weight for determining how that animal properly navigates its environment (i.e. cloudy day vs. bright blue skies). In this case then, the animal’s compass would likely use wind direction (for the sake of argument), or another sensory cue, so the animal’s ability to properly traverse its environment and achieve its goal remains intact. Assuming, neurons from different sense modalities are integrated before/within the compass, and the fly can achieve similar behavioral goals/outcomes, do we know if there are neurons/circuit motifs in place that could allow for this sort of “information gating” or synapse reweighing in the central complex?
In the paper with the realistic scenes that you mentioned, the offset for the compass changes for different scenes. Sorry if I missed this, but how does this play into the mathematics of the vector addition?
Thank you for the great talk!!
gotta meet with my PI, but thanks again larry
Thank you so much!