Affiliations: [a] Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA | [b] Department of Pathology, University of Sao Paulo Medical School, Sao Paulo, Brazil | [c] Department of Psychiatrics, University of Wuerzburg, Germany
Correspondence:
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Correspondence to: Lea T. Grinberg MD, PhD, Memory and Aging Center, Department of Neurology, Sandler Neurosciences Center, Box 1207, 675 Nelson Rising Lane, Room 211B, San Francisco, CA 94158, USA. Tel.: +1 415 502 7229; Fax: +1 415 476 5573; lea.grinberg@ucsf.edu
Abstract: Pharmacological interventions in Alzheimer’s disease (AD) are likely to be more efficacious if administered early in the course of the disease, foregoing the spread of irreversible changes in the brain. Research findings underline an early vulnerability of the isodendritic core (IC) network to AD neurofibrillary lesions. The IC constitutes a phylogenetically conserved subcortical system including the locus coeruleus in pons, dorsal raphe nucleus, and substantia nigra in the midbrain, and nucleus basalis of Meynert in basal forebrain. Through their ascending projections to the cortex, the IC neurons regulate homeostasis and behavior by synthesizing aminergic and cholinergic neurotransmitters. Here we reviewed the evidence demonstrating that neurons of the IC system show neurofibrillary tangles in the earliest stages of AD, prior to cortical pathology, and how this involvement may explain pre-amnestic symptoms, including depression, agitation, and sleep disturbances in AD patients. In fact, clinical and animal studies show a significant reduction of AD cognitive and behavioral symptoms following replenishment of neurotransmitters associated with the IC network. Therefore, the IC network represents a unique candidate for viable therapeutic intervention and should become a high priority for research in AD.
