Regulated Release and Polarized Localization of Brain-Derived Neurotrophic Factor in Hippocampal Neurons

Mol Cell Neurosci. 1996 Mar;7(3):222-38. doi: 10.1006/mcne.1996.0017.

Abstract

The site and regulation of neurotrophic factor release from neurons is poorly understood. We used a combination of model cell lines and primary culture systems to study the polarity of BDNF sorting and the regulation of its release from hippocampal neurons. Transfection and expression of a human BDNF cDNA in a mouse pituitary cell line, AtT20, resulted in the colocalization of BDNF with the secretory granule marker, chromogranin A. Furthermore, stimulation of these cells with 56 mM KCl or with 5 mM 8-bromo-cAMP increased the release of BDNF approximately 10-to 15-fold within 30 min. To study BDNF release from primary cultures of hippocampal neurons, cells were infected with a defective Herpes Simplex Viral (HSV) vector expressing human BDNF. Depolarizing conditions increased the release of BDNF 5-fold from these cells, further verifying that secretion is regulated. Immunocytochemical analysis using highly specific antibodies determined that endogenous BDNF was predominantly localized to the somatodentritic domain of hippocampal neurons. These findings support the view that BDNF functions as a target-derived signal for afferents to hippocampal pyramidal cells and that it may serve as a regulator of hippocampal plasticity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Biomarkers
  • Brain-Derived Neurotrophic Factor / analysis
  • Brain-Derived Neurotrophic Factor / metabolism*
  • Cell Polarity / physiology
  • Cells, Cultured / metabolism
  • Cytoplasmic Granules / chemistry
  • Dogs
  • Fluorescent Antibody Technique
  • Gene Expression Regulation, Enzymologic / physiology
  • Genetic Vectors*
  • Herpes Simplex*
  • Hippocampus / cytology*
  • Humans
  • Kidney Tubules, Distal / cytology
  • Mice
  • Nerve Growth Factors / analysis
  • Nerve Growth Factors / metabolism*
  • Neuronal Plasticity / physiology
  • Neurons, Afferent / chemistry
  • Neurons, Afferent / metabolism*
  • Neurons, Afferent / ultrastructure
  • PC12 Cells / chemistry
  • PC12 Cells / metabolism
  • PC12 Cells / ultrastructure
  • Pyramidal Cells / chemistry
  • Pyramidal Cells / metabolism
  • Pyramidal Cells / ultrastructure
  • Rats
  • Signal Transduction / physiology
  • Transfection
  • beta-Galactosidase / genetics

Substances

  • Biomarkers
  • Brain-Derived Neurotrophic Factor
  • Nerve Growth Factors
  • beta-Galactosidase