ISIFO SIKA-ALZHEIMER: INGABE I-NEURON PLASTICITY IYAQHUBEKA NOKUBOHLOKA KWE-AXONAL NEUROFIBRILLARY?
I-New England Journal of Medicine, Umq. 313, amakhasi 388-389, 1985
ISIFO SIKA-ALZHEIMER: INGABE I-NEURON PLASTICITY IYAQHUBEKA NOKUBOHLOKA KWE-AXONAL NEUROFIBRILLARY?
KuMhleli: U-Gajdusek ucabanga ukuthi ukuphazanyiswa kwe-neurofilaments kuyisisekelo sezifo eziningana zokudangala (umagazini ka-March 14). 1 Ukuze achaze ukuthi kungani amanye ama-neurons ebuchosheni athintekayo hhayi amanye, uphakamisa ukuthi amangqamuzana anezihlahla ezinkulu ze-axonal, ngenxa yezidingo zabo ezinkulu zokuthutha i-axonal, asengozini yokulimala kwe-axoskeletal. I-hypothesis kaGajduseks iyathandeka kodwa yehluleka ukulandisa ngokuqaphela ukuthi ama-otor neurons amakhulu athinteke kancane esifweni i-Alzheimer's.
Siphakamisa ukuthi ipulasitiki yamaseli kanye nobukhulu besihlahla se-axonal kungase kubeke izidingo ekuthuthweni kwe-axonal. I-plasticity yamaseli e-neural iye yahlotshaniswa nezinto ezihlukahlukene ze-trophic,2 ezinye zazo zibandakanya ukuthuthwa kwe-axonal. Isibonelo esifanelekile ukuhluma okubonwa kumatheminali e-septal norepinephrine,3 ngokunokwenzeka kuhambisana nokungena okukhulu kwama-neurofilaments amasha.
Ama-Neurons abonisa izinga eliphezulu le-plasticity cishe akha i-substrate ye inkumbulo nokufunda; bobabili bakhubazekile esifo i-Alzheimer's. Izindlela ze-norepinephrine ziye zahlotshaniswa nokufunda okuhlobene nomvuzo, i-4 futhi amaseli we-norephinephrine we-locus ceruleus ayabhujiswa kwezinye izimo Isifo i-Alzheimer's.5 Ukuncipha kwe-Alzheimer kulimaza nendawo yomsuka wamaseli e-serotonin ku-raphe yobuchopho obuphakathi,6 futhi i-serotonin iye yahlongozwa njengomlamuleli we-classic conditioning.7 Izindlela ze-acetylcholine eziphuma ku-nucleus basalis yaseMeynert kuya ku-cortex zingase zibe nendima. ye-latchkey kwinkumbulo eyinkimbinkimbi ukugcinwa nokubuyiswa,8.9 futhi njengoba kwaziwa kahle, isifo se-Alzheimer sihlotshaniswa nokulahlekelwa kwala maseli kanye nama-enzyme awo.10 Ezingeni le-cortical ukuwohloka kohlobo lwe-Alzheimer kuthinta kakhulu i-neuron ezindaweni ezihlangene, ngokuphawulekayo i-hippocampus ne-amygdala, 11 zombili ezidlala indima enkulu enkumbulweni.12 Ngaphezu kwalokho, ukuwohloka kwe-neurofibrillary kwenzeka ngokukhetha kuma-neurons ane-axon exhuma i-hippocampus ne-entorhinal cortex.13 Njengoba ama-neurons avela kuqembu ngalinye kulawa enza ukuxhumana okuhlotshaniswa nokufakwa kwekhodi yolwazi,14 okudinga izinga eliphezulu lepulasitiki, ukuwohloka kwawo kusekela umbono wokuthi amangqamuzana abonisa ipulasitiki enkulu athambekele ekuphazamisekeni kwe-neurofibrillary.
Ukuphazamiseka kwendlela yokuhamba kancane ye-axonal-zokuthutha kuma-neurons anezinga eliphakeme lepulasitiki kungase kuholele ekungasebenzi kahle kwenkumbulo okugcwele, uphawu oluyisisekelo ukuwohloka komqondo kungakhathaliseki ukuthi iyini imbangela. Lokhu kungasebenzi kahle kwe-axonal-filament kungase kunikeze isisekelo se-micropathological sesixhumanisi esithunyelwe ngaphambili phakathi kwe-microtubular diathesis kanye nohlobo lwe-Alzheimer. ukuwohloka komqondo 15,16 nokuhlanganisa isigaba esincane sezifo zokuwohloka komqondo.
J. Wesson Ashford, MD, Ph.D.
U-Lissy Jarvik, MD, Ph.D.
I-UCLA Neuropsychiatric Institute
I-Los Angeles, CA 90024