brain plasticity - what causes it?
kckpaulc at aol.comABCXYZ
Mon Nov 8 04:38:07 EST 1999
>it's a difficult problem because disease conditions typically destroy, to a
>degree, the ability of the nervous system to converge upon specific
>configurations. effective use of 'drugs' would have to restore such. but how
>can such be achieved when the underlying tissue has 'gone away'?
should've been: how can such be =fully= achieved... 'take-over' of deinervated
cortex, following, for instance, loss of a limb, verifies that 'plasticity'
does take advantage of the newly-vacated cortex, yielding some
'recovery'-usefulness of the pre-existing neural architecture, even if the
'recovery' is with respect to unrelated functionality.
and similar 'plasticity', following stroke, verifies that some of the
functionality that's lost, with the tissue that's lost, can be 'recovered' to a
degree. the externally-observable discrepancies between pre-stroke and
post-stroke behaviors (say, the return of speach, but 'slurred' speach)
discloses that some functionality can be restored, via 'plasticity', but the
observable discrepancies that it's been restored either through a partial
'repair' (subset rewiring) within what remains of the original tissue, or via
round-about wiring, as in the case of limb loss, above, but retaining the
principle-of-the-functionality of the leisioned tissue, if not the same neural
with respect to an earlier post of mine in this thread, it's the elimination of
stereotypy within what remains after the leisions (including relatively-distant
neural architecture) that enables this sort of 'rush' of new 'plasticity'...
all via simple TD E/I-minimization.
...all wonderful glimpses into the great 'plasticity' of the nervous system.
cheers, ken (K. P. Collins)
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