title: Selective vulnerability of synaptic signaling and metabolism to nitrosative stress.
abstract: CONCLUSIONS
  Nitric oxide (NO) plays diverse physiological roles in the central nervous system, where it modulates neuronal communication, regulates blood flow, and contributes to the innate immune responses. In a number of brain pathologies, the excessive production of NO also leads to the formation of reactive and toxic intermediates generically termed reactive nitrogen species (RNS). RNS cause irreversible or poorly reversible damage to brain cells.
  
  
  BACKGROUND
  Recent work in the field focused on the ability of NO and RNS to yield protein modifications, including the S-nitrosation of cysteine residues, which, in many instances, impact cellular functions and viability.
  
  
  RESULTS
  The vast majority of neuropathological studies focus on the loss of cell viability, but nitrosative stress may also strongly impair the functions of neuronal processes: axonal projections and dendritic trees. The functional integrity of axons and dendrites critically depends on local metabolism and effective delivery of metabolic enzymes and organelles. Here, we summarize the existing literature describing the effects of nitrosative stress on the major pathways of energetic metabolism: glycolysis, tricarboxylic acid cycle, and mitochondrial respiration, with the emphasis on modifications of protein thiols.
  
  
  CONCLUSIONS
  We propose that axons and dendrites are highly vulnerable to nitrosative stress because of their low glycolytic capacity and high dependence on timely delivery of metabolic enzymes and organelles from the cell body. Thus, supplementation with the end products of glycolysis, pyruvate or lactate, may help preserve metabolism in distal neuronal processes and protect or restore synaptic function in the ailing brain.
authors.affiliation: Center for Neuropharmacology and Neuroscience, Albany Medical College, New York 12208, USA. mongina@mail.amc.edu
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Mongin
authors.forename: Preeti
authors.initials: P
authors.lastname: Dohare
authors.forename: David
authors.initials: D
authors.lastname: Jourd'heuil
mesh_terms: D000818:Animals; D002490:Central Nervous System / Q000378:metabolism; D006801:Humans; D009569:Nitric Oxide / Q000378:metabolism; D015538:Nitrosation / Q000502:physiology*; D026361:Reactive Nitrogen Species / Q000378:metabolism
chemical_list: D026361:Reactive Nitrogen Species; D009569:Nitric Oxide