Alzheimer's disease-related alterations in synaptic density: Neocortex and hippocampus

Article type: Research Article

Authors: Scheff, Stephen W.^{; *} | Price, Douglas A.

Affiliations: Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY 40536-0230, USA

Correspondence: [*] Corresponding author: Stephen W. Scheff, Sanders-Brown Center on Aging, Room 101 Sanders-Brown, University of Kentucky, Lexington, KY 40536-0230, USA. Tel.: +1 859 257 1412 ext 270; Fax: +1 859 323 2866; E-mail: sscheff@email.uky.edu.

Abstract: Alzheimer's disease (AD) is a progressive disorder that is characterized by the accumulation of neuropathologic lesions and neurochemical alterations. Ultrastructural investigations in many association regions of the neocortex and the hippocampal dentate gyrus have demonstrated a disease-related decline in numerical synaptic density. This decline in brain connectivity occurs early in the disease process and strongly correlates with the cognitive decline observed in AD. The synapse loss does not appear to be an inevitable consequence of the aging process. This article reviews the ultrastructural studies assessing AD-related synaptic loss and the possible compensatory changes in the synaptic complex that occur as a result of the loss in brain connectivity.

Keywords: Plasticity, limbic, cognition, synapse, ultrastructure

DOI: 10.3233/JAD-2006-9S312

Journal: Journal of Alzheimer's Disease, vol. 9, no. s3, pp. 101-115, 2006