Catching the engram: strategies to examine the memory trace

Tagging neural ensembles using a c-fos promoter tTA/TetOLacZ-tTA mouse. The mouse has two transgenic alleles. One allele encodes the doxycycline sensitive ... Skiptomaincontent Advertisement SearchallBMCarticles Search Figure3|MolecularBrainTaggingneuralensemblesusingac-fospromotertTA/TetOLacZ-tTAmouse.Themousehastwotransgenicalleles.Onealleleencodesthedoxycyclinesensitivetetracyclinetransactivator(tTA)underthecontrolofthec-fospromoter.tTAbindsthetetracyclineoperator(TetO)sequencetoinducetranscriptionofthedownstreamgene,andtheinductionactivityissuppressedbythepresenceofdoxycycline.Theotherexpressesthesecondarytransactivator(tTA*)andtauLacZunderthecontrolofTetO.tTA*isbothinsensitivetodoxycyclineandconstitutivelyactive,therefore,onceexpressed,tTA*activatesTetOregardlessofdoxycycline.A.tTAisexpressedexclusivelyinneuronswherethec-fospromoterisactivated.However,inthepresenceofdoxycycline,tTAactivityisinhibitedandhencepreventsinteractionwithTetO.B.Afterwithdrawalofdoxycycline,tTAisactivatedandbindstoTetOtoinduceexpressionoftTA*andtauLacZproteininc-fosactivatedneurons(purple).C.Afterre-administrationofdoxycycline,tTAbecomesinactivatedonceagainbutastTA*isstillpresent,itcanmaintaintheexpressionoftauLacZbyactivatingTetOinthepositive-feedbackloop.Thissystemtherebyallowsthepermanenttaggingofneuronsactivatedevenintheabsenceofdoxycycline.Backtoarticlepage MolecularBrain ISSN:1756-6606 Contactus Submissionenquiries:AccesshereandclickContactUs Generalenquiries:[email protected]