Why 'Wanting' and 'Liking' something
simultaneously is overwhelming?
Wanting and liking are separate urges controlled by different brain
circuits and when combined at once, the impact on the brain is especially
powerful, according to University
of Michigan research (Smith and Berridge, 2007).
The U-M study reports that the brain divides
wanting and liking into separate circuits for the same sweet reward. Natural heroin-like chemicals (opioids) in a few brain
"pleasure hotspots" make individuals want to eat more of a tasty
sweet food, and make them like its sweet taste more when they eat it, the study
says. The same thing happens with addictions to drugs, sex, gambling and other
pursuits involving "brain reward" circuits.
The researchers Kyle Smith and Kent
Berridge show that two different brain circuits carry out the wanting and
liking for the sweet reward, even when both are triggered in the same brain
pleasure hotspots.
"We typically want what we
like, and like what we want," Smith said. "But these results suggest
that wanting and liking are processed by distinct brain circuits and may not
always go hand-in-hand."
Experimenters put an opioid drug
(Damgo) into a pleasure hotspot in the brains of rats—in the front base of the
brain—using a painless microinjection technique to deliver tiny chemical
droplets to the brain target without disturbing the rats.
The opioid made the rats want to eat
three times more food than normal, and to show double the normal number of
"liking" expressions when they tasted the sugar.
"Liking" expressions are
positive facial lip licking expressions that are similar in rats, monkeys, apes
and even human infants.
"The brain seems to be more stingy with
mechanisms for pleasure than for desire," Berridge said.
To turn off a particular brain circuit, the
experimenters simultaneously made another microinjection of an
opioid-suppressing chemical—in a different pleasure hotspot of the brain in
some rats.
The opioid-suppressing chemical in that second
hotspot completely prevented any increase in liking for the sugar taste from
being caused by the first opioid-activating drug in the nucleus accumbens.
Nucleus accumbens
Nucleus accumbens shell (neuronal cover around core),
but not core,
tracks motivational value (Loriaux et al., 2011)
But the opioid-activation in nucleus
accumbens still caused the rats to want to eat triple the normal amount of
food, even though the extra "liking" for it was gone.
A single looping circuit between hotspots was
found to be always activated by microinjections that caused
pleasure liking.
On the other hand, a different outgoing
circuit from nucleus accumbens appeared to cause the
wanting by going to the hypothalamus instead.
The U-M study reports that the brain divides
wanting and liking into separate circuits for the same sweet reward.
Natural heroin-like chemicals (opioids) in a
few brain "pleasure hotspots" make individuals want to eat more of a
tasty sweet food, and make them like its sweet taste more when they eat it, the
study says. The same thing happens with addictions to drugs, sex, gambling and
other pursuits involving "brain reward" circuits
The findings suggest that liking and
wanting for tasty treats can either change together or change separately,
depending on which brain circuits are involved.
For example, various eating
disorders might involve different activation patterns in the two brain circuits,
possibly dissociating liking from wanting in some cases but not in others.
"It's relatively
hard for a brain to generate pleasure, because it needs to activate
different opioid sites together to make you like something more," Berridge
said.
"It's easier to activate
desire, because a brain has several 'wanting' pathways available for the task. Sometimes
a brain will like the rewards it wants. But other times it just wants
them."
This
is what neuroscience opened for us. The scientific materials make it clear why majority
of people live under “the pressure of wanting”. The question arises easily: “Where
is satisfaction?”
Wanting
something strongly and not getting it, leads first to hyper-agitation, then to
stress. Life without satisfaction and physical pleasure fills the body with
tension.
It
turns out that most of people have no natural mechanisms of pleasure and
satisfaction, i.e. feeling happily released and good! To compensate for this shortage
or lack, people over-drink, over-eat and “over-do” other things they are not
proud of.
What
can be done? I found the solution to this problem and will reveal the
information in my book
“Pain?
Gone!”
I
still have not finished it because the mystery was uncovered for me only today.
The truth is so simple and elegant, that all pain disappears very fast, within
minutes.
Reference
articles
- Kyle S. Smith
and Kent C.
Berridge. Opioid Limbic
Circuit for Reward: Interaction between Hedonic Hotspots of Nucleus
Accumbens and Ventral Pallidum. The Journal of Neuroscience, 14 February 2007, 27(7): 1594-1605; doi: 10.1523. JNEUROSCI.4205-06.2007. Abstract/FREE
Full Text
- Amy L. Loriaux, Jamie D. Roitman,
and Mitchell F. Roitman. Nucleus
accumbens shell, but not core, tracks motivational value of salt J Neurophysiol September 2011 106:Abstract/
Full Text
/ Full Text
(PDF)/ Supplemental
Figures and Tables. 1537-1544; published ahead of
print June 22, 2011, doi:10.1152/jn.00153.2011 0022-3077 1522-1598 .
Love,
Natalia
Levis-Fox
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