Monday, November 21, 2011

Touch sense is enhanced by deafness gene

Voltage-gated K+ channel protein KCNQ4
We recently discussed the role of ion channels in membrane potentials of excitable cells in my A&P class.  I don't think my students believe me when I say that ion channels are a "hot area" of neuroscience research and that understanding them better will lead to all kinds of new insights about how our nervous system works.

Well, today in Nature Neuroscience researchers reveal that a gene for a protein in voltage-gated potassium channels in sensory cells that is mutated in a form of progressive deafness is also responsible for helping us sense vibration in the skin.  When the gene is mutated, it limits hearing.  But the mutation heightens touch sensitivity in the skin. 

So folks with this form of deafness lose hearing but gain touch sensitivity. 

However, there doesn't seem to be any measurable advantage to the increased touch sensitivity.  Probably, there is a disadvantage.

The important thing here, I think, is that it shows us something about how this particular potassium ion channel, which inhibits neuron excitability, can be used to adjust the sensitivity of sensory neurons for touch.

Studies such as this help us understand that certain genes can be expressed in different cells and have similar functions--but different roles to play.  It also underscores the tendency of the human body to make more than one use of a particular process. 

If our A&P students start looking for the same mechanisms that appear in different parts of the body, then they'll gain a deeper understanding of human structure and function.

Want to know more?

Deafness Gene Heightens Touch
Tia Ghose
TheScientist November 20, 2011
[Brief news article summarizing the discovery]

KCNQ4 K+ channels tune mechanoreceptors for normal touch sensation in mouse and man

M. Heidenreich, et. al.
Nature Neuroscience  20 November , 2011

[Original research article]

1 comment:

Anonymous said...

Why Music Touches Us
March 23, 2006
Nov 11, 2005 DH, in biologicalEvolution forum

On music 'touching/moving' us:

Music is a human cultural - artifactual elaboration of creatures' vocal communication which is an extension-elaboration of >24 wks-old in-womb fetus' and of newborns' intimate safe/coddle/sooth experiences. Both 'touch' and 'hear' senses are founded on mechanical sensing processes involving in-cell ions leakage forming electrical action potentials interpreted neurologically.
I suggest/conjecture that the same neurological constellation may be handling both 'touch' and 'hear' senses, being of commom mechanisms and differing essentially only in switch-on modes, and that this evolves in all vocal creatures in conjunction with in-womb safety, followed with baby codling/handling and vocal soothing/communicating, and later also with intimate emotional implications. Hence music has 'engulfing-touching-emotional' connotation and personal music orientation has also childhood-ethnic roots.

Dov Henis (comments from 22nd century)

Post a Comment