ISIFO SIKA-ALZHEIMER: INGABA I-NEURON PLASTICITY IYA KUXHALASELWA NGE-AXONAL NEUROFIBRILLARY?
New England Journal of Medicine, Vol. 313, iphepha 388-389, 1985
ISIFO SIKA-ALZHEIMER: INGABA I-NEURON PLASTICITY IYA KUXHALASELWA NGE-AXONAL NEUROFIBRILLARY DENERATION?
KuMhleli: I-Gajdusek iqikelela ukuba ukuphazamiseka kwe-neurofilaments kuyisiseko sezifo ezininzi eziphazamisayo (i-14 kaMatshi). 1 Ukucacisa ukuba kutheni ezinye ii-neurons ezingqondweni zichaphazelekayo kwaye kungekhona ezinye, ucebisa ukuba iiseli ezinemithi emikhulu ye-axonal, ngenxa yeemfuno zabo ezinkulu zokuthutha i-axonal, zisengozini kakhulu kumonakalo we-axoskeletal. I-hypothesis ye-Gajduseks inomtsalane kodwa iyasilela ukunika ingxelo ngokuqaphela ukuba ii-otor neurons ezinkulu zichaphazeleka kancinane kwi-Alzheimer's disease.
Sicebisa ukuba iplastiki yeeseli kunye nobukhulu bomthi we-axonal inokunyanzelisa iimfuno zothutho lwe-axonal. Iplastiki yeeseli ze-neural iye yanxulumana nezinto ezahlukeneyo zetrophic,2 ezinye zazo zibandakanya ukuthuthwa kwe-axonal. Umzekelo ofanelekileyo kukuhluma okubonwa kwi-septal norepinephrine terminals,3 kuqikelelwa ukuba ikhatshwa kukuthontelana okukhulu kweeneurofilaments ezintsha.
IiNeurons ezibonisa umgangatho ophezulu weplastiki mhlawumbi zenza i-substrate ye inkumbulo kunye nokufunda; bobabini banokukhubazeka kwisifo sika-Alzheimer. Iindlela ze-norepinephrine ziye zanxulunyaniswa nokufunda okunxulumene nomvuzo, i-4 kunye neeseli ze-norephinephrine ze-locus ceruleus zitshatyalalisiwe kwezinye iimeko Isifo se-Alzheimer.5 I-Alzheimer's degeneration nayo iyonakalisa indawo yemvelaphi yeeseli ze-serotonin kwi-raphe ye-midbrain, i-6 kunye ne-serotonin iye yacetywayo njengomlamli we-classic conditioning.7 Iindlela ze-acetylcholine eziphuma kwi-nucleus basalis yaseMeynert ukuya kwi-cortex ingaba nendima. yelatchkey kwimemori enzima ukugcinwa kunye nokubuyiswa, i-8.9 kwaye njengoko kuyaziwa, isifo se-Alzheimer sihambelana nokulahlekelwa kwezi mizimba yeeseli kunye ne-enzymes yazo.10 Kwinqanaba le-cortical i-Alzheimer-type deterioration ichaphazela ngokukhethekileyo i-neuron kwiindawo ezidibeneyo, ngokugqithiseleyo i-hippocampus kunye ne-amygdala, I-11 zombini idlala indima enkulu kwimemori.12 Ngaphezu koko, ukuchithwa kwe-neurofibrillary kwenzeka ngokukhethiweyo kwi-neurons kunye ne-axons edibanisa i-hippocampus kunye ne-entorhinal cortex. Iqondo eliphezulu leplastiki, ukuwohloka kwabo kuxhasa ingqikelelo yokuba iiseli ezibonisa iplastiki eninzi zinokuphazamiseka kwe-neurofibrillary.
Ukuphazamiseka kwendlela ecothayo ye-axonal-transport kwi-neurons enenqanaba eliphezulu leplastiki kunokukhokelela kukungasebenzi kakuhle kwememori, uphawu oluphambili isifo sengqondo esiyingozi nokuba siyintoni na isizathu. Ukungasebenzi kakuhle kwe-axonal-filament kunokubonelela ngesiseko se-micropathological kwikhonkco elithunyelwe ngaphambili phakathi kwe-microtubular diathesis kunye nohlobo lwe-Alzheimer. isifo sengqondo esixhalabisayo 15,16 kwaye sibophe kunye udidi olungaphantsi lwezifo eziphazamisayo.
J. Wesson Ashford, MD, Ph.D.
ULissy Jarvik, MD, Ph.D.
UCLA Neuropsychiatric Institute
Los Angeles, CA 90024