TY - JOUR T1 - Cortical and subcortical cholinergic innervation in normal aging JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1749 LP - 1749 VL - 51 IS - supplement 2 AU - Nicolaas Bohnen AU - Martijn Muller AU - Roger Albin AU - Robert Koeppe AU - Michael Kilbourn AU - Kirk Frey Y1 - 2010/05/01 UR - http://jnm.snmjournals.org/content/51/supplement_2/1749.abstract N2 - 1749 Objectives There are two major sources of cholinergic projections in the brain. The nucleus basalis of Meynert provides the principal cholinergic input of the cortical mantle and the pedunculopontine nucleus provides the major cholinergic input to the thalamus. Neurodegenerative processes may preferentially involve these systems but effects of normal aging are not well studied. We investigated the effects of normal aging on cortical and thalamic cholinergic afferent integrity by measuring brain acetylcholinesterase (AChE) activity in middle-aged and elderly normal subjects. Methods Community-dwelling subjects (n=32, 14F/18M, mean age 65.9±10.3, range 50-84, mean Mini-Mental State Examination 29.8±0.5, range 28-30) underwent AChE [11C]methyl-4-piperidinyl propionate (PMP) PET imaging. No subjects were taking cholinergic or anti-cholinergic drugs. Results Mean cortical and thalamic AChE k3 hydrolysis rates were 0.0302±0.0033 and 0.0640±0.0068 min-1, respectively. Increasing age was associated with lower cortical (Rs= -0.38, P<0.05) but not with thalamic AChE activity (Rs= -0.08, ns). Conclusions Normal aging may have selective effects on cortical but not on thalamic cholinergic afferent projections. Lower cortical cholinergic activity in the elderly may increase the risk of cognitive and other side-effects when exposed to anti-cholinergic drugs. Research Support NIH P01 NS015655, Department of Veterans Affairs and the Michael J Fox Foundation ER -