Jeevan Padiyar's Link Blog

Interesting findings from the interewebs

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neuromorphogenesis:

What Makes Memories Last?

Prions can be notoriously destructive, spurring proteins to misfold and interfere with cellular function as they spread without control. New research, published in the open access journal PLOS Biology on February 11, 2014, from scientists at the Stowers Institute for Medical Research reveals that certain prion-like proteins, however, can be precisely controlled so that they are generated only in a specific time and place. These prion-like proteins are not involved in disease processes; rather, they are essential for creating and maintaining long-term memories.

“This protein is not toxic; it’s important for memory to persist,” says Stowers researcher Kausik Si, Ph.D., who led the study. To ensure that long-lasting memories are created only in the appropriate neural circuits, Si explains, the protein must be tightly regulated so that it adopts its prion-like form only in response to specific stimuli. He and his colleagues report on the biochemical changes that make that precision possible.

Si’s lab is focused on finding the molecular alterations that encode a memory in specific neurons as it endures for the days, months, or years—even as the cells’ proteins are degraded and renewed. Increasingly, their research is pointing toward prion-like proteins as critical regulators of long-term memory.

In 2012, Si’s group demonstrated that prion formation in nerve cells is essential for the persistence of long-term memory in fruit flies. Prions are a fitting candidate for this job because their conversion is self-sustaining: once a prion-forming protein has shifted into its prion shape, additional proteins continue to convert without any additional stimulus.

Si’s team found that in fruit flies, the prion-forming protein Orb2 is necessary for memories to persist. Flies that produce a mutated version of Orb2 that is unable to form prions learn new behaviors, but their memories are short-lived. “Beyond a day, the memories become unstable. By three days, the memory has completely disappeared,” Si explains.

In the new study, Si wanted to find out how this process could be controlled so that memories form at the right time. “We know that all experiences do not form long-term memory—somehow the nervous system has a way to discriminate. So if prion-formation is the biochemical basis of memory, it must be regulated.” Si says. “But prion formation appears to be random for all the cases we know of so far.”

Si and his colleagues knew that Orb2 existed in two forms—Orb2A and Orb2B. Orb2B is widespread throughout the fruit fly’s nervous system, but Orb2A appears only in a few neurons, at extremely low concentrations. What’s more, once it is produced, Orb2A quickly falls apart; the protein has a half-life of only about an hour.

“When Orb2A binds to the more abundant form, it triggers conversion to the prion state, acting as a seed for the conversion. Once conversion begins, it is a self-sustaining process; additional Orb2 continues to convert to the prion state, with or without Orb2A. By altering the abundance of the Orb2A seed”, Si says, “cells might regulate where, when, and how the conversion process is engaged”. But how do nerve cells control the abundance of the Orb2A seed?

Their experiments revealed that when a protein called TOB associates with Orb2A , it becomes much more stable, with a new half-life of 24 hours. This step increases the prevalence of the prion-like state and explains how Orb2’s conversion to the prion state can be confined in both time and space.

The findings raise a host of new questions for Si, who now wants to understand what happens when Orb2 enters its prion-like state, as well as where in the brain the process occurs. While unraveling these mechanisms will likely be more accessible in the fruit fly than in more complex organisms, Si points out that proteins related to Orb2 and TOB have also been found in the brains of mice and humans. He has already shown that in the sea snail Aplysia, conversion to a prion-like state facilitates long-term change in synaptic strength. “This basic mechanism appears to be conserved across species,” he notes.

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caitluffs:

applethefruit:

crrocs:

how am i supposed to make creative funny text posts when nothing happens in my life at all

you just use a story from sims and pretend it really happened to you

one time i was swimming but the pool ladders disappeared so i couldn’t get out of the pool and i swam for 10 hours then died

(via troyesivan)

3,880 notes

neuromorphogenesis:

Human brain reacts to emoticons as real faces
Humans have developed to read :-) in the same way as a human face, but do not have the same connection with (-:

Emoticons such as :-) have become so important to how we communicate online that they are changing the way that our brains work.


They are used to provide clues to the tone of SMS, emails and tweets that can be hard to succinctly describe in words alone. But Dr Owen Churches, from the school of psychology at Flinders University in Adelaide, has found that they have become so important that we now react to them in the same way as we would to a real human face.


When we see a face there is a very specific reaction in certain parts of the brain such as the occipitotemporal cortex. When that image of a face is inverted there is another very specific reaction. This can be tracked using advanced brain scanning techniques.


Churches found that the same reaction occurred when 20 participants in a study were shown emoticons, but only when they were viewed in the traditional, left-to-right format. When they were “inverted”, or flipped to be read right-to-left, the expected reaction was not found.


This showed that humans have now developed to read :-) in the same way as a human face, but do not have the same connection with (-:. The study, published in the Social Neuroscience journal, also included participants being shown real faces and meaningless strings of characters as controls.


Emoticons and evolution.

neuromorphogenesis:

Human brain reacts to emoticons as real faces

Humans have developed to read :-) in the same way as a human face, but do not have the same connection with (-:

Emoticons such as :-) have become so important to how we communicate online that they are changing the way that our brains work.

They are used to provide clues to the tone of SMS, emails and tweets that can be hard to succinctly describe in words alone. But Dr Owen Churches, from the school of psychology at Flinders University in Adelaide, has found that they have become so important that we now react to them in the same way as we would to a real human face.

When we see a face there is a very specific reaction in certain parts of the brain such as the occipitotemporal cortex. When that image of a face is inverted there is another very specific reaction. This can be tracked using advanced brain scanning techniques.

Churches found that the same reaction occurred when 20 participants in a study were shown emoticons, but only when they were viewed in the traditional, left-to-right format. When they were “inverted”, or flipped to be read right-to-left, the expected reaction was not found.

This showed that humans have now developed to read :-) in the same way as a human face, but do not have the same connection with (-:. The study, published in the Social Neuroscience journal, also included participants being shown real faces and meaningless strings of characters as controls.

Emoticons and evolution.

17,605 notes

neuromorphogenesis:

Dream On: Why Sleep is So Important 

This infographic showcases some studies on just how dangerous—and costly—sacrificing sleep can be, and it concludes with some facts on how you can try and improve your sleep quality if it’s something you struggle with. 

by  JASON (FRUGAL DAD)

Sleep facts.