It occurs to me that people might hesitate to download such a long
post, so I'm re-posting the references with most of the rest of it
trimmed:
In <73an3m$dgn at sjx-ixn5.ix.netcom.com> flefever at ix.netcom.com(F. Frank
LeFever) writes:
>>>Deep in the following exchange, John inserted two requests for further
>info; one re the corpus callosum and neurochemical interhemispheric
>balance, and another about cc function more broadly.
>>re cc and neurochem balance:
>>Glick, S.D. et al. (1975) Nature, 254, 616-617.
>>This was in the context of a long series of papers on various aspects
>of hemispheric asymmetries (usually focused on caudate differences),
>for which do a Medline search for years c. 1974-84? I had forgotten,
>until I pulled his file to answer John's request, that I had invited
>Stanley to speak to a meeting of the New York Neuropsychology Group,
c.
>1983! He sooon relocated to Albany, and much of his recent work has
>been on aspects of the neurochemistry of drug addiction, which I
>personally do not find so intteresting as the interhemispheric
>relations work; but he is still doing some of that--viz.,
>>Carlson, J.N. et al. (incl. Glick)(1996) Brain Research, 711, 1-9.
>>Carlson, J.N. et al. (ditto) (1996) Brain Research, 707, 122-126.
>>For other approaches to interhemispheric relations (mainly via cc),
>here are a few oldies from my files:
>>Williamson, P.D. et al. (1985) Neurology, 35, 1069-1071.
>(relevant to the idea that a malfunctioning hemisphere can interfere
>with an intact hemisphere's performance of a task)
>>Liederman, J. et al. (1985) Neuropsychologia, 23, 673-683.
>(relevant to interhemispheric collaboration)
>>Dennis, M. (1976) Neuropsychologia, 14, 455-469.
>(suggests role for callosal inhibition in development)
>>Banquet, J.P. (1983) Electroencephalography and Clinical
>Neurophysiology, 55, 51-59.
>(provocative suggestion of role for cc in phase synchronization, in
>contrast to frequency synchronization via thalamo-cortical circuits)
>>More recent work? Liederman still in busines (q.v.)
>Using Ovid disk for last 4 yrs of Medline, search strategy using
>"interhemispheric AND cognition" yielded 13 articles;
"interhemispheric
>AND inhibition" yielded 16 more.
>>for ex:
>>Baynes, K. et al. (1998) Science, 280, 902-905
>>F. Frank LeFever, Ph.D.
>New York Neuropsychology Group
>>>>>In <7319r3$mbv$1 at news.bix.asn.au> "John" <go at away.com> writes:
>>>>>>- - - - - -(snip) - - - - - - - - - -
>>>> Besides a pretty good general professional knowledge of not oonly
>the
>>>> corpus callosum but also the anterior commissure, posterior
>commissure,
>>>> and hippocampal commissure (to say nothing of indirect influences
>via
>>>> the diencephalon), there are several more "personal" experiences
to
>>>> keep me alert to interhemispheric relationships.
>>>>>>>> For ex., about 35 years ago, in preparation for research with a
>recent
>>>> post-doc from Sperry's lab (a "classmate" of Gazzaniga's), I was
>>>> practicing corpus callosum section and unilateral hippocampal
>excisions
>>>> in (dead) cat heads--project fell through when NYU delayed too
>long in
>>>> buying cages for LIVE cats.
>>>>>>>> For ex., about 18-20 years ago, one of my patients with MS, a
>>>> right-hander, switched to the left hand to do the Block Design
>(WAIS).
>>>> Having seen demonstrations of the superiority of left-hand Block
>Design
>>>> performances by split-brain patients (compared to right-hand), I
>had
>>>> the sudden insight that inasmuch as the corpus callosum is the
>largest
>>>> myelinated stucture in the brain, MS patients may have a partial
>>>> disconnection syndrome--unfortunately, did not write this up, but
>>>> others have indeed demontrated that this is true.
>>>>>>>> For ex., sometime in the past 20-30 years, a former student of
mine
>>>> (Stanley Glick) found that the CC was impoortant in
>neurotransmitter
>>>> balance across the hemispheres--after it was cut, prior DA
>asymmetries
>>>> increased and ACh asymmetries developed.
>>>>>>This sounds interesting, where can I read about it?
>>>>>> About 15 years ago, using a computer-driven visual display I built
>>>> (LEDs in a plexiglass dome) I was able to replicate Brend Milner's
>>>> finding of a slight latency difference between ipsilateral and
>>>> contralateral reaction times in a patient with callosal agenesis
>(about
>>>> the same order of magnitude as she found, if I recall correctly).
>>>>>>>> More recently (5-6 yrs?), a former colleague, Robert Sloviter,
>>>> described long inhibitory fibers from each hippocampus to the
other
>(I
>>>> heard it from the horse's mouth).
>>>>>>>> ACCOORDINGLY, you may be sure I did not forget callosal
>transmission
>>>> when I wrote about unilateral vs. bilateral ECT.
- - - - -(snip) - - - - - - - - - -
>>>>Talking of the cc, can you direct me to a good text dealing with
>theories
>>regarding just what is happening here? I sometimes wonder if the cc
is
>>overlooked to some extent yet this massive bundle must provide
>important
>>clues. Is it true that across the visual cortex the numbe of cc
>connections
>>increases from primary to tertiary visual structures? If so, can you
>>speculate on what this may indicate?
- - - - - -(snip) - - - - - - - - -