Cerebrospinal fluid levels of the synaptic protein neurogranin correlates with cognitive decline in prodromal Alzheimer's disease

Alzheimers Dement. 2015 Oct;11(10):1180-90. doi: 10.1016/j.jalz.2014.10.009. Epub 2014 Dec 19.


Introduction: Synaptic dysfunction is an early event in Alzheimer's disease (AD) pathogenesis and directly related to cognitive impairment. Consequently, synaptic biomarkers may be valuable tools for both early diagnosis and disease stage. Neurogranin (Ng) is a postsynaptic protein involved in memory consolidation.

Methods: We developed three monoclonal anti-Ng antibodies. Mass spectrometry and a novel enzyme-linked immunosorbent assay were used to analyze cerebrospinal fluid (CSF) Ng in three independent clinical cohorts including patients with AD dementia (n = 100 in total), mild cognitive impairment patients (MCI), (n = 40) and controls (n = 80 in total).

Results: We show in three independent clinical cohorts a marked increase in CSF Ng levels in AD dementia (P < .001 in all studies). In addition, high CSF Ng levels at the MCI stage predicted progression to dementia due to AD with a hazard ratio of 12.8 (95% confidence interval 1.6-103.0, P = .02). In amyloid-positive MCI patients, high CSF Ng correlated with a more rapid change in cognition during clinical follow-up (P = .03).

Discussion: These results suggest that CSF Ng is a novel AD biomarker that may be used to monitor synaptic degeneration, and correlates with the rate of cognitive decline in prodromal AD.

Keywords: Alzheimer's disease; ELISA; Mass spectrometry; Mild cognitive impairment; Neurogranin; Prognostic marker.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alzheimer Disease / complications
  • Alzheimer Disease / diagnosis*
  • Alzheimer Disease / physiopathology*
  • Biomarkers / cerebrospinal fluid*
  • Case-Control Studies
  • Cognition Disorders / etiology*
  • Cognitive Dysfunction / diagnosis
  • Disease Progression
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Male
  • Mass Spectrometry
  • Middle Aged
  • Neurogranin / cerebrospinal fluid*
  • Prognosis
  • Time Factors


  • Biomarkers
  • Neurogranin