Hitting head, seeing stars

Alexander Reiprich Alexander.Reiprich at uni-duesseldorf.de
Thu Oct 24 13:00:22 EST 1996


Ron Blue wrote:
> 
> > What I find really interesting is that it's not just random points of
> > "light", It's randomly *moving* points of light. The stars sort of swim
> > around in little wavy arcs. They appear to be generated at random
> > locations in the visual field, then swim a little way, then fade out
> > quickly, but not instantaneously. It's really pretty cool. So my theory
> > about this is that we're not just "seeing" some neurons firing, but
> > actually watching the propagation of activity in waves across fields of
> > neurons through the tissue. As a thumbnail estimate, I'd say that each
> I agree totally with Matt.  This is very similar to migraine auras
> reported by Oliver Sachs.  This is in my opinion due to interacting
> wavelet trains and the temporary lost of homestatis.
> Ron Blue
I do not know too much about migraine auras but as far as I know there
exists a model involving spreading depressions which can be initiated in
the neocortex in vitro by short time hypoxia, application of potassium
or glutamate, high frequency stimulation and maybe also by mechanical
stress.
SD's are characterized by slowly (2-3 mm/min) spreading waves of
membrane depolarizations possibly propagated by gap junctions. These
waves can move in all directions and are often several times reflected
so that several depolarizations in can be observed on one recording
point. 
In my eyes this could well explain the observation of wandering stars
after traumatic injuries if the visual cortex would be more sensitive to
a temporary lost of homeostatis than other cortical areas.



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