18987.不同背景亮度下貓初級視皮層神經(jīng)元的on反應和off反應

1、分類號UDC密級編號中國科學院研究生院碩士學位論文丕國萱量壺廛至貓麴級塑皮屋袖經(jīng)丞的Q叢廈應麴QEE廈應袁鋒展鋒指導教師三塑班塞雖生墾科堂陵生物塑堡硒宜壓申請學位級別亟學科專業(yè)名稱生物物堡堂論文提交日期2Q至2生壘旦論文答辯日期2Q12生墨旦培養(yǎng)單位主國型堂瞳生物物理巫塞壓學位授予單位主國型堂陵硒塞生院二零一二年一／I月一夸一一=中月AbstractFengYuan(Biophysics)SupervisedbyProfYiWangLu

2、minanceinformationisthefundamentalinformationthatthevisualsystemreceives，whichincludestheincrement(ON)anddecrement(OFF)inlightlevelTheearlyvisualsystemhastwopathwaystoprocessthelightluminanceOneistheONpathwaytodetectthel

3、ightincrement，andtheotherisOFF‘pathwaytodetectthelightdecrementIntheearlystageofthevisualinformationprocessing，theONpathwayandtheOFFpathwayarelargelyseparate，andconvergeintheprimaryvisualcortexforthefirsttimeThepreviouss

4、tudiesindicatethatOFFdominantcellsoutnumberONdominantcells，andtheOFFpathwaydominatesoverON—pathwayintheprimaryvisualcortex(v1)TheseresultsaremainlyobtainedinafixedbackgroundluminanceThebackgroundluminance，howeverisnotcon

5、stantinthenaturalenvironmentTherefore，whetherthedominanceofOFFresponseoverONresponsemaintainsoverbackgroundluminanceremainsunknownThepsychologicalexperimentsshowthatthethresholdstodetectluminanceincrementanddecrementarer

6、elatedwiththebackgroundluminanceinhuman，buttheconclusionlacksthesupportofphysiologicalresultsWestudiedONresponseandOFFresponseoftheneuronsinthecatVlindifferentbackgroundluminances，andanalyzedtheONsubregionandtheOFFsubreg

7、ionoftheirreceptivefieldsWeshowedthattheOFFdominancewasmoreobviousinalowbackgroundluminanceWiththebackgroundluminanceincreasing，theONresponseincreasedsignificantlytheOFFresponsedidnotshowobviouschanges，andasaresulttheOFF

8、dominancewasweakenedMoreoverthepeaktimeofOFFresponsewasshorterthanthatofONresponse，andbothofthembecameshortenasthebackgroundluminanceincreasedTheseresultsareconsistentwiththoseofthepreviouspsychologicalexperimentsWediscu