Let's study ID: what dopamine does (Introduction)

by David Turell @, Sunday, October 31, 2021, 19:17 (34 days ago) @ David Turell

How did chance mutations find this specific molecule?:


"Among the neurotransmitters in the brain, dopamine has gained an almost mythical status. Decades of research have established its contribution to several seemingly unrelated brain functions including learning, motivation, and movement, raising the question of how a single neurotransmitter can play so many different roles.

"Untangling dopamine's diverse functions has been challenging, in part because the advanced brain of humans and other mammals contain different kinds of dopamine neurons, all embedded in highly complex circuits. In a new study, Rockefeller's Vanessa Ruta and her team dive deep into the question by looking instead at the much simpler brain of the fruit fly, whose neurons and their connections have been mapped in detail.

"As in humans, a fly's dopamine neurons provide a signal for learning, helping them to link a particular odor to a particular outcome. Learning that, for example, apple cider vinegar contains sugar serves to shape the animals' future behavior on their next encounter with that odor. But Ruta's team discovered that the same dopamine neurons also correlate strongly with the animal's ongoing behavior. The activity of these dopamine neurons does not simply encode the mechanics of movement, but rather appears to reflect the motivation or goal underlying the fly's actions in real time. In other words, the same dopamine neurons that teach animals long-term lessons also provide moment-to-moment reinforcement, encouraging the flies to continue with a beneficial action.


"They found that the activity of dopamine neurons closely reflects movements as they were happening, but only when the flies engage in purposeful tracking, and not when they are just wandering about.


"Together, the findings reveal how one dopamine pathway can perform two functions: conveying motivational signals to rapidly shape ongoing behaviors while also providing instructive signals to guide future behavior through learning. "It gives us a deeper understanding of how a single pathway can generate different forms of flexible behavior," Ruta says."

Comment: look at its structure which is not complex:


But very valuable in its various actions in a brain. What are the chances of finding it? About 10^22 chances as natural odds. But then think about an average enzyme, thousands of which are necessary to make life's reactions occur, and each one contains thousands of amino acids in specific patterns, so their odds have to be 10 to the thousands. Each vital molecule has to be found to make life work. So the odds for life on a finding basis for one bacteria is 2x10^100,000,000,000!!! (quote in my science vs religion book, page 77). Only a finding designer fits.

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