Recently, they've recommenced animal studies, which Keysers says are necessary to map "a more detailed wiring diagram, in terms of what neurons speak to what neuron with what neurotransmitters".
Thus, the ARD distribution closely matches that of the boutons of the cha-Tan neurons, but it is not clear what neuron type(s) expresses the receptor.
As Yuste explained to me, the key goal of the project is not to map what neurons are connected to which other neurons (yielding a static "connectome"), but to visualize the action of all the individual neurons in a given organism simultaneously, as organisms behave, akin to the difference between a snapshot and a high-resolution video.
At Janelia Farm, Dr. Card is continuing the work on fly takeoff, using a variety of methods, like turning different brain circuits on and off, to attempt to understand just how the fly brain makes the decision — what exactly happens in what neurons in the milliseconds between the sight of a predator and takeoff.
The latter is what neurons respond to according to the response-averaging model.
To confirm circuitry integration, and to map what neurons form synaptic inputs to the newly reprogrammed cells, we used modified rabies virus (ΔG-rabies) to trace connectivity of the reprogrammed neurons.
It would help to be more specific as to what neurons (presumably at a level higher than the IC) are being considered here (indeed, there are precious few spatially tuned neurons at higher levels, and the hemispheric model doesn't require such neurons, does it?).
However, even if the intensity of a stimulus has a high variance, and it is correlated with reward, it is not useful to a neuron if it is highly predictable, since it would merely be telling the neuron what the neuron already knows.
"We've created mathematical models of what a neuron does when it receives a signal, and then, having processed it, sends out a different signal," he said.
To define what a neuron's electrical phenotype is, one would need to know what the function of a given neuronal type is.
According to Charles Stevens of the Salk Institute, our brains distinguish noise from signal through redundancy of neurons and a canny averaging of what those neurons have to say.
