title: Correlations and discrepancies between serum and brain tissue levels of neurotrophins after electroconvulsive treatment in rats.
abstract: BACKGROUND
  The neurotrophin brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) are a central part of the molecular concepts on neuroplastic changes associated with stress, anxiety and depression. An increasing number of studies uses serum BDNF levels as a potential indicator for central nervous system alterations.
  
  
  METHODS
  To analyze the relationship between brain tissue and serum BDNF and NGF levels, we used electroconvulsive shocks (ECS), an animal model of electroconvulsive therapy, and studied the temporal profile of neurotrophin expression in the hippocampus, prefrontal cortex and serum. 88 male Sprague-Dawley rats received single or serial ECS treatments and were killed between 3 hours and 14 days after the last treatment.
  
  
  RESULTS
  We found a 2.8-fold rise for BDNF (1.3-fold for NGF) in the prefrontal cortex, and a 2.2-fold rise (1.2-fold for NGF) in the hippocampus after 5 ECS sessions. The temporal expression profile and correlation analyses between tissue and serum BDNF indicate that BDNF crosses the blood-brain barrier. No such correlation was found for NGF.
  
  
  CONCLUSIONS
  The time course of central and peripheral BDNF changes may significantly differ. However, we demonstrate substantial evidence that it can be justified to measure serum BDNF levels with a time delay to monitor brain tissue neurotrophin alterations.
authors.affiliation: Central Institute of Mental Health, Department of Psychiatry and Psychotherapy, Mannheim, Germany. alexander.sartorius@zi-mannheim.de
authors.forename: A
authors.initials: A
authors.lastname: Sartorius
authors.forename: R
authors.initials: R
authors.lastname: Hellweg
authors.forename: J
authors.initials: J
authors.lastname: Litzke
authors.forename: M
authors.initials: M
authors.lastname: Vogt
authors.forename: C
authors.initials: C
authors.lastname: Dormann
authors.forename: B
authors.initials: B
authors.lastname: Vollmayr
authors.forename: H
authors.initials: H
authors.lastname: Danker-Hopfe
authors.forename: P
authors.initials: P
authors.lastname: Gass
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000502:physiology*; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood* / Q000378:metabolism*; D004565:Electroconvulsive Therapy / Q000379:methods; D006624:Hippocampus / Q000502:physiology; D008297:Male; D020932:Nerve Growth Factor / Q000097:blood* / Q000378:metabolism*; D017397:Prefrontal Cortex / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D020932:Nerve Growth Factor