Tragic events like wars, famines, earthquakes, and accidents create fearful memories in our brain. These memories continue to haunt us even after the actual event has passed. Luckily, researchers from Tokyo University of ...
Apr 25, 2022
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(Medical Xpress) -- Traditionally, treatment for drug addicts has centered around so-called extinction procedures designed to disassociate memories tied with taking drugs to help reduce the cravings that so often result in ...
(Medical Xpress) -- The antidepressant fluoxetine, which is marketed under the name "Prozac," has been approved for use in the US for over two decades, and while some people find it effective, the results vary widely from ...
QBI researchers have discovered a DNA modification that enhances our ability to extinguish fear.
Feb 19, 2019
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(Medical Xpress) -- Neuroscientists at UQ's Queensland Brain Institute have discovered a previously unrecognized layer of gene regulation associated with fear extinction.
Aug 15, 2011
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Modern Papuans' immune system likely evolved with a little help from the Denisovans, a mysterious human ancestor who interbred with ancient humans, according to a new study led by Irene Gallego Romero of the University of ...
Dec 8, 2022
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Fear is an important survival mechanism and so too is the ability to inhibit fear when it's no longer needed. In order to counter-balance fear, the brain engages in fear extinction. In this process, memories are formed during ...
May 4, 2020
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(Medical Xpress) -- In a new study, University of Michigan researchers identified brain circuits in rats that are responsible for the return of fear after it has been suppressed behaviorally.
Nov 29, 2011
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Endogenous cannabinoids, or endocannabinoids for short, are lipid-based neurotransmitters known to support various physiological processes. Recent studies have hinted at the role of these neurotransmitters in so-called fear ...
A new study by Weill Cornell Medical College researchers shows that adolescents' reactions to threat remain high even when the danger is no longer present. According to researchers, once a teenager's brain is triggered by ...
Sep 27, 2012
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In biology and ecology, extinction is the end of a species or group of taxa. The moment of extinction is generally considered to be the death of the last individual of that species (although the capacity to breed and recover may have been lost before this point). Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "re-appears" (typically in the fossil record) after a period of apparent absence.
Through evolution, new species arise through the process of speciation—where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche—and species become extinct when they are no longer able to survive in changing conditions or against superior competition. A typical species becomes extinct within 10 million years of its first appearance, although some species, called living fossils, survive virtually unchanged for hundreds of millions of years. Extinction, though, is usually a natural phenomenon; it is estimated that 99.9% of all species that have ever lived are now extinct.
Prior to the dispersion of humans across the earth, extinction generally occurred at a continuous low rate, mass extinctions being relatively rare events. Starting approximately 100,000 years ago, and coinciding with an increase in the numbers and range of humans, species extinctions have increased to a rate unprecedented since the Cretaceous–Tertiary extinction event. This is known as the Holocene extinction event and is at least the sixth such extinction event. Some experts have estimated that up to half of presently existing species may become extinct by 2100.
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