Pupillary cholinergic hypersensitivity predicts cognitive decline in community dwelling elders.

Previous research demonstrated that it is possible to distinguish patients with probable Alzheimer's disease from age-matched controls based on an exaggerated pupil dilation response to dilute tropicamide. The research reported here employed a prospective longitudinal design to follow over time (2-4 years) a sample of 55 community dwelling elders with and without an exaggerated pupil response using the pupil assay and a comprehensive battery of neuropsychological tests sensitive to pre-clinical AD. Discrete time survival modeling was used to assess the ability of the assay to predict a pattern of cognitive decline consistent with early AD.

Age-related differences in novelty and target processing among cognitively high performing adults.

Previous research on age-related changes in ERP components in response to novel and target stimuli has not carefully controlled for differences in level of cognitive status between age groups, which may have contributed to the common findings of increased P3 latency, decreased P3 amplitude, and altered P3 scalp distribution. Here, cognitively high-performing (top third based on published norms) old, middle-aged, and young adults matched for IQ, education, and gender participated in a novelty oddball paradigm. There were no age-associated differences in P3 latency.

Use of IQ-adjusted norms to predict progressive cognitive decline in highly intelligent older individuals.

Identifying high-functioning older individuals in preclinical phases of Alzheimer's disease (AD) may require more sensitive methods than the standard approach. The authors explored the utility of adjusting for premorbid intelligence to predict progressive cognitive decline or Mild Cognitive Impairment (MCI) in 42 highly intelligent older individuals. When scores were adjusted for baseline IQ, 9 participants had executive impairments, 11 had memory impairments, and 22 scored in the normal range.

Loss of calbindin-D28k from aging human cholinergic basal forebrain: relation to neuronal loss.

Cholinergic neurons of the basal forebrain (BFCN) are selectively vulnerable in neurodegenerative disorders of the elderly, particularly in Alzheimer's disease (AD). We investigated age-related changes in the BFCN that may serve as a substrate for this vulnerability. We report a substantial and selective age-related loss of the calcium binding protein calbindin-D(28K) (CB) from the human BFCN.