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Unformatted text preview: kly Cha t on the Hotte st Topics in Scie nce Thurs day s 3 p.m. EDT
Sc i enc eNO W . ISSN 1947- 8062 Thos e differenc es trans lated into improvements on behavioral tes ts . Mic e with human as troc y tes performed better on
memory ex periments than thos e that had rec eived mous e c ell grafts , the team reports today in Cell Stem Cell. The
human as troc y te-endowed rodents learned to fear a partic ular s ound or part of their environment after as s oc iating
them jus t onc e with an elec tric s hoc k . This learning pers is ted for 3 day s , during whic h time ty pic al mic e did not
learn at all, des pite being treated in ex ac tly the s ame way . The mic e with trans planted human c ells als o learned to
find their way through a maz e in about half the time and were better able to rec ogniz e familiar objec ts in new
loc ations .
The res ults s upport the view that human brain evolution involved c ellular s pec ializ ations , inc luding the elaboration of
as troc y te s truc ture and a boos t in their ability to regulate c ommunic ation between neurons at s y naps es , the
res earc hers s ay . news.sciencemag .or g /sciencenow/2013/03/human- br ain- cells- boost- mouse- me.html?r ef= hp 1/2 4/24/13 Human Br ain Cells Boost M ouse M emor y - ScienceNOW Thes e are "very interes ting findings [that] s trongly s ugges t that human as troc y tes have an enhanc ed ability to
c ontrol s y naps es ," s ay s neurobiologis t Ben Barres of Stanford Univers ity in Palo Alto, California. But he adds that
the s tudy does not s how that human as troc y tes are genetic ally normal when engrafted into the mous e brain, and it
does not rule out the idea that the improved learning and memory "c ould be due to the pers is ting progenitor c ells ."
"It would be interes ting to s ee if they get the s ame effec ts by engrafting c himpanz ee or mac aque glia," adds
evolutionary neuroanatomis t Todd Preus s of the Yerk es National Primate Res earc h Center at Emory Univers ity in
Atlanta. This c ould determine whether the obs erved effec ts are due to properties that are unique to human c ells or
c ommon to thos e of all primates .
Goldman ac k nowledges thes e limitations , but he believes that the work will lead to a new way of inves tigating
neurologic al and ps y c hiatric dis orders . "W e c an generate glial progenitors from reprogrammed human s k in c ells ," he
s ay s , "and have already c reated mic e with glia from s c hiz ophrenic patients ." Suc h animals would be better than
ex is ting animal models for tes ting potential new treatments , he s ugges ts .
Chimeric mic e c ould als o provide more c lues about brain evolution by helping res earc hers identify as troc y te
s pec ializ ations that are unique to humans . "Many neuros c ientis ts are unc omfortable with open dis c us s ion of human
s pec ializ ations for fear that the adequac y of their animal model will be c alled into ques tion," Pre...
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