Introducing the brain: precise synapse controls (Introduction)

by David Turell , Wednesday, April 20, 2022, 15:26 (736 days ago) @ David Turell

Signals very carefully modulated:

https://medicalxpress.com/news/2022-04-enzyme-brain.html

"Almost 100 billion nerve cells perform their service in the human brain. Each of these has an average of 1,000 contacts with other neurons. At these so-called synapses, information is passed on between the nerve cells.

"However, synapses are much more than simple wiring. This can already be seen in their structure: They consist of a kind of transmitter device, the presynapse, and a receiver structure, the postsynapse. Between them lies the synaptic cleft. This is actually very narrow. Nevertheless, it prevents the electrical impulses from being easily transmitted. Instead, the neurons in a sense shout their information to each other across the gap.

"For this purpose, the presynapse is triggered by incoming voltage pulses to release certain neurotransmitters. These cross the synaptic cleft and dock to specific "antennae" on the postsynaptic side. This causes them to also trigger electrical pulses in the receiver cell. "However, the amount of neurotransmitter released by the presynapse and the extent to which the postsynapse responds to it are strictly regulated in the brain," explains Prof. Dr. Susanne Schoch McGovern of the Department of Neuropathology at University Hospital Bonn.

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"'We have now shown that a protein called RIM1 plays a key role in this process," says Schoch McGovern. RIM1 is clustered in the so-called "active zone" of the presynapse—the area where neurotransmitters are released.

"Like any protein, RIM1 consists of a large number of contiguous amino acids. The researchers have now shown that some of these amino acids are linked by an enzyme to a chemical compound, a phosphate group. Depending on which amino acid is modified in this way, the presynapse can subsequently release more or less neurotransmitter. The phosphate groups form the "memory" of the synapses, so to speak, with which they remember the current activity level. "In the presynapse, transmitter-filled vesicles stand ready to be fired like the arrows of a taut bow," Dietrich says. "As soon as a voltage pulse comes in, they are released at lightning speed. Phosphorylation changes the number of these vesicles.'" (my bold)

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"This means that the brain can presumably adjust the activity of individual synapses very precisely via RIM1. Another key role is played by the enzyme SRPK2: It attaches the phosphate groups to the amino acids of RIM1. However, there are also other players, such as enzymes that remove the phosphate groups again if necessary. "We assume that there is a whole network of enzymes that act on RIM1 and that these enzymes also control each other's activity," Dietrich explains."

Comment: as usual, we see very fine tuning to modulate brain activity as my bold shows. Only a designer can create such a system with individual amino acids precisely changed or modified