Natures wonders: insect migration; fly brain vector math (Introduction)

by David Turell , Thursday, December 16, 2021, 14:41 (1071 days ago) @ dhw

A careful study of fly neurons:

https://www.sciencedaily.com/releases/2021/12/211215113221.htm

"Neurons in the fly brain appear to literally perform vector math in order to signal the direction in which their bodies are traveling, regardless of which way their heads are pointing.

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"How the brain calculates an animal's direction of travel when the head is pointing one way and the body is moving in another is a mystery in neuroscience.

"A new study makes significant headway on solving this mystery by reporting that the fly brain has a set of neurons that signal the direction in which the body is traveling, regardless of the direction in which the head is pointing. The findings, published in Nature, also describe in detail how the fly's brain calculates this signal from more basic sensory inputs.

"'Not only do these neurons signal the fly's direction of travel, but they do also so in a world-centered reference frame," says Rockefeller neuroscientist Gaby Maimon. What's remarkable, adds first author Cheng Lyu, a graduate student in the Maimon lab, is that these insects are transforming body-referenced sensory inputs into a world-referenced signal, allowing the fly to know that it is traveling, for instance, 90 degrees to the right of the sun or northward.

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"Lyu glued fruit flies to miniature harnesses that hold only the insects' heads in place, enabling him to record brain activity while leaving the flies free to flap their wings and steer their bodies through a virtual environment. The setup contained several visual cues, including a bright light representing the sun and a field of dimmer dots that could be adjusted to make the fly feel like it was being blown backward or sideways.

"As expected, the head direction cells consistently indicated the fly's orientation to the sun, simulated by the bright light, independently of the dimmer dots' motion. In addition, the researchers identified a new set of cells that indicated which way the flies were traveling, and not just the direction their head was pointing. For example, if the flies were oriented directly toward the sun in the east while being blown backward, these cells indicated that the flies were (virtually) traveling west. "This is the first set of cells known to indicate which way an animal is moving in a world-centered reference frame," Maimon says.

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"'We make a strong argument that what's happening here is an explicit implementation of vector math in a brain." Maimon says. "What makes this study unique is that we show, with extensive evidence, how neuronal circuits implement relatively sophisticated mathematical operations."

"The present research clarifies how flies figure out which way they're going, in the moment."

Comment: as the article notes, our brain doe the same thing. How did this ability develop? Not by chance. It is so important to all activity by all organisms, it fits the need for
design.