Affordable Access

Publisher Website

The length of hippocampal cholinergic fibers is reduced in the aging brain

Authors
Journal
Neurobiology of Aging
0197-4580
Publisher
Elsevier
Publication Date
Volume
29
Issue
11
Identifiers
DOI: 10.1016/j.neurobiolaging.2007.04.001
Keywords
  • Aging
  • Cholinergic Axons
  • Cholinergic Neurons
  • Septohippocampal Pathway
  • Medial Septal Nucleus
  • Hippocampus
  • Stereology
  • Spherical Probe
  • Optical Fractionator Probe
  • Synaptophysin
  • Nerve Growth Factor
  • Brain-Derived Neurotrophic Factor
  • Tropomyosin Related Kinase Receptor A
  • Tropomyosin Related Kinase Receptor B
  • P75 Neurotrophin Receptor
  • Choline Acetyltransferase
Disciplines
  • Biology
  • Chemistry
  • Medicine

Abstract

Abstract Cholinergic deficits occur in the aged hippocampus and they are significant in Alzheimer's disease. Using stereological and biochemical approaches, we characterized the cholinergic septohippocampal pathway in old (24 months) and young adult (3 months) rats. The total length of choline acetyltransferase (ChAT)-positive fibers in the dorsal hippocampus was significantly decreased by 32% with aging ( F (1,9) = 20.94, p = 0.0014), along with the levels of synaptophysin, a presynaptic marker. No significant changes were detected in ChAT activity or in the amounts of ChAT protein, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), tropomyosin related kinase receptor (Trk) A, TrkB, or p75 neurotrophin receptor (p75 NTR) in the aged dorsal hippocampus. The number and size of ChAT-positive neurons and the levels of ChAT activity, NGF and BDNF were not statistically different in the septum of aged and young adult rats. This study suggests that substantial synaptic loss and cholinergic axonal degeneration occurs during aging and reinforces the importance of therapies that can protect axons and promote their growth in order to restore cholinergic neurotransmission.

There are no comments yet on this publication. Be the first to share your thoughts.