title: Ca2+ sparks and Ca2+ glows in superior cervical ganglion neurons.
abstract: OBJECTIVE
  Ca2+ release from the endoplasmic reticulum (ER) is an integral component of neuronal Ca2+ signaling. The present study is to investigate properties of local Ca2+ release events in superior cervical ganglion (SCG) neurons.
  
  
  METHODS
  Primary cultured SCG neurons were prepared from neonatal rats (P3-P7). Low concentration of caffeine was used to induce Ca2+ release from the ER Ca2+ store, and intracellular Ca2+ was recorded by high-resolution line scan confocal imaging and the Ca2+ indicator Fluo-4.
  
  
  RESULTS
  Two populations of local Ca2+ release events with distinct temporal characteristics were evoked by 1.5 mmol/L caffeine near the surface membrane in the soma and the neurites of SCG neurons. Brief events similar to classic Ca2+ sparks lasted a few hundreds of milliseconds, whereas long-lasting events displayed duration up to tens of seconds. Typical somatic and neurite sparks were of 0.3- and 0.52-fold increase in local Fluo-4 fluorescence, respectively. Typical Ca2+ glows were brighter (deltaF/F0 approximately 0.6), but were highly confined in space. The half maximum of full duration of neurite sparks was much longer than those in the soma (685 vs 381 ms).
  
  
  CONCLUSIONS
  Co-existence of Ca2+ sparks and Ca2+ glows in SCG neurons indicates distinctive local regulation of Ca2+ release kinetics. The local Ca2+ signals of variable, site-specific temporal length may bear important implications in encoding a 'memory' of the trigger signal.
authors.affiliation: Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou 310031, China.
authors.forename: Li-jun
authors.initials: LJ
authors.lastname: Yao
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.forename: Kun-fu
authors.initials: KF
authors.lastname: Ou-Yang
authors.forename: Chao-liang
authors.initials: CL
authors.lastname: Wei
authors.forename: Xian-hua
authors.initials: XH
authors.lastname: Wang
authors.forename: Shi-rong
authors.initials: SR
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Yao
authors.forename: Hong-ping
authors.initials: HP
authors.lastname: Huang
authors.forename: Jian-hong
authors.initials: JH
authors.lastname: Luo
authors.forename: Cai-hong
authors.initials: CH
authors.lastname: Wu
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Zhuan
authors.initials: Z
authors.lastname: Zhou
authors.forename: He-ping
authors.initials: HP
authors.lastname: Cheng
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002110:Caffeine / Q000037:antagonists & inhibitors; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects*; D002478:Cells, Cultured; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D051381:Rats; D017783:Superior Cervical Ganglion / Q000166:cytology / Q000378:metabolism*; D019284:Thapsigargin / Q000494:pharmacology
chemical_list: D002110:Caffeine; D019284:Thapsigargin; D002118:Calcium