title: [Level of brain-derived neurotrophic factor in the microenvironment of the neuron-astrocyte co-culture system by Mg2+-free-induced seizure-like discharge].
abstract: OBJECTIVE
  To study the level of brain-derived neurotrophic factor (BDNF) in the microenvironment of the neuron-astrocyte co-culture system by Mg2+-free-induced seizure-like discharge and analyze the source of BDNF.
  
  
  METHODS
  Hippocampal neurons (N) of fetal rats and astrocytes (AST) of neonatal rats were purified and divided into four groups, included control N (Con N) group, Mg2+-free treated N (Mg2+-free N) group, control N+AST co-culture (Con N+AST) group and Mg2+-free treated N+AST co-culture (Mg2+-free N+AST) group. The Mg2+-free treated groups were exposed to Mg2+-free media for 3 hrs to induce a repeated spontaneous seizure-like discharge. The level of BDNF in each group at different time points was measured using ELISA.
  
  
  RESULTS
  The cellular morphous of AST changed in the Mg2+-free N+AST group at 48 hrs. Neuronal epileptiform activity was observed in the Mg2+-free media at 3 hrs, and continued to exist until the microenvironment returned to normal for 72 hrs. The BDNF level increased at 24 hrs and 48 hrs in the Con N+AST group compared with the control N group (P<0.05). Compared with Con N+AST group, BDNF level increased at 12, 24 and 48 hrs in the Mg2+-free N+AST group, especially at 12 and 24 hrs (P<0.01). There were no significant differences in the level of BDNF between the Con and Mg2+-free N groups. Compared with Mg2+-free N group, BDNF level increased at 24 hrs in the Mg2+-free N+AST group (P<0.05).
  
  
  CONCLUSIONS
  The results of the experiment suggest that BDNF in the Con N+AST group might be excreted from both N and AST, but chiefly from N. Activated AST may be the main source for increasing BDNF in the Mg2+-free N+AST group.
authors.affiliation: Department of Neurology, Children's Hospital, Chongqing University of Medical Science, Chongqing, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Wen
authors.forename: Li
authors.initials: L
authors.lastname: Jiang
authors.forename: Heng-Sheng
authors.initials: HS
authors.lastname: Chen
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000737:chemistry*; D019208:Brain-Derived Neurotrophic Factor / Q000032:analysis*; D060833:Cellular Microenvironment; D018920:Coculture Techniques; D005260:Female; D006624:Hippocampus / Q000737:chemistry; D008275:Magnesium Deficiency / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000378:metabolism*
chemical_list: D019208:Brain-Derived Neurotrophic Factor