Tuesday, November 29, 2011

Caffeine strengthens synapses

Can caffeine help us learn A&P (or anything else)?  Can it improve our memory?

Recent research published in Nature Neuroscience this week suggests that the answer may be yes.  In animal studies, caffeine strengthened synaptic connections in the hippocampus of the brain.  That's not enough to demonstrate that caffeine will be an effective learning enhancer . . . but is does suggest the possibility.

We've been talking about synapses and memory in our A&P 1 course recently, so I thought you might also.  And perhaps want to drop in this tidbit about the latest research.

Next time our students ask how they can possibly remember everything in the A&P course, perhaps a trip to the campus coffee shop may be in order, eh?

Want to know more?
Coffee delivers jolt deep in the brain
Laura Sanders
Science News Web edition : Monday, November 21st, 2011

[A brief synopsis discussing the discovery.]

Caffeine-induced synaptic potentiation in hippocampal CA2 neurons
Stephen B Simons, et. al.
Nature Neuroscience (2011) Published online 20 November 2011 doi:10.1038/nn.2962

[The original research article]

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]