Variations in Acetylcholinesterase Activity within Human Cortical Pyramidal Neurons Across Age and Cognitive Trajectories.
We described an extensive network of cortical pyramidal neurons in the human brain with abundant acetylcholinesterase (AChE) activity. Emergence of these neurons during childhood/adolescence, attainment of highest density in early adulthood, and virtual absence in other species led us to hypothesize involvement of AChE within these neurons in higher cortical functions. The current study quantified the density and staining intensity of these neurons using histochemical procedures. Few faintly stained AChE-positive cortical pyramidal neurons were observed in children/adolescents. These neurons attained their highest density and staining intensity in young adulthood. Compared with the young adult group, brains of cognitively normal elderly displayed no significant change in numerical density but a significant decrease in staining intensity of AChE-positive cortical pyramidal neurons. Brains of elderly above age 80 with unusually preserved memory performance (SuperAgers) showed significantly lower staining intensity and density of these neurons when compared with same-age peers. Conceivably, low levels of AChE activity could enhance the impact of acetylcholine on pyramidal neurons to counterbalance other involutional factors that mediate the decline of memory capacity during average aging. We cannot yet tell if elderly with superior memory capacity have constitutively low neuronal AChE levels or if this feature reflects adaptive neuroplasticity.
Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Monica
M
Janeczek
Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Tamar
T
Gefen
Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Mehrnoosh
M
Samimi
Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Garam
G
Kim
Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Sandra
S
Weintraub
Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Eileen
E
Bigio
Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Emily
E
Rogalski
Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
M-Marsel
MM
Mesulam
Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Changiz
C
Geula
D000110:Acetylcholinesterase / Q000378:metabolism*; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D002540:Cerebral Cortex / Q000166:cytology*; D002648:Child; D002675:Child, Preschool; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016874:Neurofibrillary Tangles / Q000502:physiology; D017966:Pyramidal Cells / Q000201:enzymology*; D055815:Young Adult
D000110:Acetylcholinesterase