title: Regulatory effects of anandamide on intracellular Ca(2+) concentration increase in trigeminal ganglion neurons.
abstract: Activation of cannabinoid receptor type 1 on presynaptic neurons is postulated to suppress neurotransmission by decreasing Ca(2+) influx through high voltage-gated Ca(2+) channels. However, recent studies suggest that cannabinoids which activate cannabinoid receptor type 1 can increase neurotransmitter release by enhancing Ca(2+) influx in vitro. The aim of the present study was to investigate the modulation of intracellular Ca(2+) concentration by the cannabinoid receptor type 1 agonist anandamide, and its underlying mechanisms. Using whole cell voltage-clamp and calcium imaging in cultured trigeminal ganglion neurons, we found that anandamide directly caused Ca(2+) influx in a dose-dependent manner, which then triggered an increase of intracellular Ca(2+) concentration. The cyclic adenosine and guanosine monophosphate-dependent protein kinase systems, but not the protein kinase C system, were involved in the increased intracellular Ca(2+) concentration by anandamide. This result showed that anandamide increased intracellular Ca(2+) concentration and inhibited high voltage-gated Ca(2+) channels through different signal transduction pathways.
authors.affiliation: Department of Anesthesiology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Jingzhou Central Hospital, Jingzhou, Hubei Province, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Xie
authors.affiliation: Department of Physiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Lei
authors.affiliation: Department of Physiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China.
authors.forename: Fen
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Physiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Pan
authors.affiliation: Department of Physiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China.
authors.forename: Changjin
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Bioengineering, Wuhan Institute of Engineering, Wuhan, Hubei Province, China.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Bioengineering, Wuhan Institute of Engineering, Wuhan, Hubei Province, China.
authors.forename: Lieju
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Physiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China ; Department of Bioengineering, Wuhan Institute of Engineering, Wuhan, Hubei Province, China.
authors.forename: Xuehong
authors.initials: X
authors.lastname: Cao
keywords: NIH grant; anandamide; calcium; cannabinoid receptor type 1; cyclic adenosine monophosphate protein kinase; endocannabinoids; nerve regeneration; neural regeneration; neurons; patch-clamp technique; protein kinase C; trigeminal ganglion; vanilloid receptor; voltage-dependent calcium channels