improving the human condition
TRANSCRIPT
Importance Sleepaffectseveryone! Seriousproblems/effectsofsleepdeprivation
Decreasedmentalfunction(memory,recognition,etc.) Cardiovascularproblems,weightgain
Impact Startwithspecificapplications:large“delta”forsmallpopulation Military,Collegestudents,etc.
Photo of yawning man
Expandtobroad removed due to copyright restrictions.
applications:smaller“delta”forlargepopulation Generalproductivitybooster?
Short‐andlong‐termhealthrisks?
Knowns/Unknowns Muchisstillunknownaboutsleep
Whydowesleepatall? Whataretheresultsofsleeping?
Whatweknowaboutsleep 4Stages:N1,N2,N3,REM Occursincycleslasting90‐110 Image of cartoon cat "Garfield"
in pajamas with cup of coffee
mins. removed due to copyright restrictions.
N3,REMare“deepsleep”cycles REMonlyaccountsfor~30%ofsleep
Possibleto“isolate”REMsleep?
Competition Manyresearchinstitutioncauses/effectsofsleep
Drugstimulants Caffeine!
sareinvestigatingthe
Modafinil
Image: Wikpedia (public domain)
Courtesy of Rynosoft on Flickr.
OurIdea “Curing”sleepmightbetooambitious,givenhowlittleisknownaboutthecausesofsleep
Increasetheleveloftoleranceforcaffeinebymanipulatingtheadenosinereceptors
Photo of sleepy person with 2 coffee cupsremoved due to copyright restrictions.
Althoughsleepisnotfullyunderstood,themanipulationofneuralreceptorscouldplayanimportantroleinincreasingtolerancetosleepdeprivation
Anotherimportantmethodforimprovingthefunctioningofthebrain,andparticularlyforhealingthedamagedbrain,isthroughtheregenerationofneurons
Importance Thereisnowaytorepairdamagedneurons Seriousproblems!
Lossofmotorfunctions Braindisorders Deadneurons
Impact Affectsonlyalimitedsegmentofthepopulation(injury,Alzheimer’s,etc.)–butimpactwouldbetremendous.
Wouldallowthosewhosufferfrombraindamagetohavereturnedphysicalandmentalfunctioning
Drawing of neurons removed due to copyright restrictions.
CompetingTechnologies Useofstemcellstoreplacedamagedneurons Stimulationofnervecellstohelpregrowneuralconnectionsinthebrain
Turningofforblockingpathwaysthatinhibitregrowthofneurons ThreeinhibitorsofaxonregrowthknowntodateareNogo,myelin‐associatedglycoprotein(MAG)andmyelin‐oligodendrocyteglycoprotein(OMgp)
Knowns Basicstructureofneurons Neuralpathwaysandtheuseofneurotransmitterstocommunicatewithinthebrain
Neuronscanberegeneratedwiththeuseofstemcells
Figure by MIT OpenCourseWare.
Unknowns Efficienttechniquesforreplacingdamagedneurons Image of neurons
removed due to copyright restrictions.
Natureofgenesassociatedwiththeregenerationofneurons
•Neuronswithintheadultbrainthatregrowaxialprojectionshavebeenfound,butthegenesthatencodeforthisgrowthandtheproteinsthattheytranslatearenotwellknown
Insertingregeneratedneuronsintothebrainorstimulatingtheregenerationofneurons Image of neurons
withinthebraincould removed due to copyright restrictions.
allowfortherecoveryofmentalandphysicalfunctioning
•Neuronregenerationcouldhelptocurepatientswhosufferfromneurodegenerativediseases,suchasAlzheimer’s
Importance
Highlydegenerativediseasethatisultimatelyfatal Lowersthequalityoflifeanddecreasesthecapacitytofunctionofsocietyofthosewhosufferfromit
Anestimated26.6millionpeople65yearsandolderhadAlzheimer’sworldwidein2006
ThusAlzheimer’shasterribleandirreversibledegenerativeeffectsonalargenumberofpeople
Impact Memorymakesyouwhoyou WillhelppeoplewithAlzheidementiaretaintheirlifelon
Preservesfamilyunity ReducesHumanSuffering
are!mer’sandotherformsofgexperiences
Image removed due to copyright restrictions. Diagram comparing hemispheres of healthy andAlzheimer's brains. See: http://www.alz.org/brain/09.asp
Howtostoptheloss? Rearrangethefiberstotheiroriginalposition KILLtheplaques Weareproposingtomonitorthemusing“bio‐markers”
Blood‐BrainBarrier LimitedImagingoftheBrain
IssuesforTreatmentImage removed due to copyright restrictions.Neurons of healthy and Alzheimer's brains.See: http://www.alz.org/brain/10.asp
Knowns SenileplaquesandneurofibrillarytanglesaredirectlyassociatedwithAlzheimer’s
PossibleGeneticComponent:MutationsonChromosomes9and19
Thecellsultimatelydie Causesthebraintoshrink Proteinpiecesclumptogetherinthebrain Chemically“sticky”(theybondeasily) Theclumpsblocksignalsandultimatelykillthecells!!
Unknowns Whatcausesplaquestoform Whattypesofneuronsareaffected
Whyarecertainareasofthebrainaffected
Structureoftheproteinplaques Timethatittakestheclumpstobe“big”enoughtoblocktheneuro‐signals
“Twisted”Proteins:Whatcausesthemtoentangle?
Image removed due to copyright restrictions.Plaques diagram. See: http://www.alz.org/brain/11.asp
CompetingTechnologies ManypharmaceuticaltreatmentsfocusonneurotransmittersNOTonplaquesandtangles
ClinicalTrials TheU.S.FoodandDrugAdministrationhasapprovedfourdrugstotreatAD.ForpeoplewithmildormoderateAD,donepezil(Aricept®),rivastigmine(Exelon®),orgalantamine(Razadyne®).
Namendaregulatesglutamatewhichplaysakeyroleinprocessinginformation.
TreatmentsResearched:Breakingdownbeta‐amyloidplaques,anti‐inflammatorydrugs
Summary Manipulatingreceptorsonneuronscanplayamajorroleinthetransferof
informationthroughneuralpathways Changingadenosinereceptorscanhelpincreasetolerancetocaffeine
Caffeinesupplementscouldbemorecontinuouslyeffectiveindecreasingtheneedforsleep
Changingneuralreceptorscanalsoallowforspecificdrugtreatmentsandchemicalstobetransferredtoneuronsformedicinalpurposes
Regenerationofneuronsisamajorconcernsincemostneuronsareinastateofnon‐replication
TheregenerationofneuronscouldallowforthetreatmentofpatientswithAlzheimer’sandotherformsofdementia
TheremovalofplaquesandthedetanglingofneurofiberscouldimproveneuralfunctioningandultimatelyhelptopreventtheprogressionofAlzheimer’s
Resources http://www.pnas.org/content/100/13/7430.full http://www.alseres.com/science‐technology/nerve‐repair.asp http://www.narcis.info/research/RecordID/OND1325851/Language/en/;jsessio
nid=i0hc281m2bl http://alzheimersdiseaseaid.com/origins‐unknown‐‐the‐battle‐with‐
alzheimer‐s‐continues.php http://www.nia.nih.gov/Alzheimers/AlzheimersInformation/Treatment/
http://alzheimers.about.com/od/treatmentofalzheimers/a/treatments.htm http://web.mit.edu/newsoffice/2008/alzheimers‐protein‐0821.html
http://www.nanowerk.com/spotlight/spotid=5262.php
MIT OpenCourseWarehttp://ocw.mit.edu
20.020 Introduction to Biological Engineering Design Spring 2009
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