Masturbation and its effect

Autism isn’t just a brain disease, new evidence suggests 
This changes everything.

Researchers have found evidence that suggests
autism spectrum disorder (ASD) – conditions
characterised by impaired social ability,
repetitive behaviours, and abnormal reactions
to sensory stimuli – are not merely the result
of defects in brain development - a possibility
that scientists have been mulling over for
years.
Instead, at least some effects of ASD go
beyond the brain, and could impact the
peripheral nerves that send sensory
information from limbs to the brain, the
researchers suggest. This means that other
parts of the nervous system - besides the brain
- could partly be responsible for the way people
with ASD experience and react to stimuli.
The new study, led by David Ginty from the
Harvard Medical School, was performed on
mice, and looked at several genetic mutations
that are commonly found in people with ASD.
Two of these variants affect the genes Mecp2
and Gabrb3. Both of these genes are known to
impact synaptic function in the brain , meaning
they're essential for neurons to communicate.
The variants are typically found in people with
ASD.
"Although we know about several genes
associated with ASD, a challenge and a major
goal has been to find where in the nervous
system the problems occur," Ginty said in a
statement . "By engineering mice that have
these mutations only in their peripheral sensory
neurons, which detect light touch stimuli acting
on the skin, we've shown that mutations there
are both necessary and sufficient for creating
mice with an abnormal hypersensitivity to
touch."
When the team bred mice with these genetic
mutations , they noticed that they could no
longer use their sense of touch to navigate
different objects, and also responded differently
to puffs of air being blown on their
necks. Based on this reaction, the team
suggests that the altered mice experience
touch in a completely different way from
regular mice.
Next, they studied how these genes affected
social interactions – one of the hallmark
symptoms of ASD – by introducing genetically
altered mice to other mice and examining how
often they ventured into an open space inside
their habitats.
They found that the altered mice showed signs
of heightened anxiety compared to the
unaltered mice. The team says this anxiety
could stem from their altered sense of touch .
How does this work? The experience of touch
and other sensory stimuli might be overloading
the mice with information, causing them to get
overly nervous for what seems like no reason,
though the team is still investigating this
hypothesis.
"A key aspect of this work is that we've shown
that a tactile, somatosensory dysfunction
contributes to behavioural deficits, something
that hasn't been seen before," Ginty said . "In
this case, that deficit is anxiety and problems
with social interactions."
The team’s findings suggest that ASD might
not just be brain related. Instead, genetic
mutations could make those with ASD actually
feel and sense the world differently – on a
physical level – than those without it.
The best way to think about these findings is
to imagine that your sense of touch has a
volume knob. For most of us, this knob would
be turned to, say, five. For someone with an
ASD, it might be as high as 10, making
everyday tasks feel heightened to the point of
chaos. The team is basically saying that this
'volume knob' is controlled by genes, not a
brain disease.
"The sense of touch is important for mediating
our interactions with the environment, and for
how we navigate the world around us," said
one of the team, Luren Orefice. "An abnormal
sense of touch is only one aspect of ASD, and
while we don't claim this explains all the
pathologies seen in people, defects in touch
processing may help to explain some of the
behaviours observed in patients with ASD."
It’s important to point out that the study was
only done with mice. While these results are
promising, they need to be replicated in
humans for them to have relevance for future
treatments.
But it's an intriguing insight into what could be
going on in a disease that we still don't really
understand, and which affects roughly 3.5
million Americans .
The study has been published in the journal
Cell.