Transition between two excitabilities in mesencephalic V neurons.
Neurons can make different responses to identical inputs. According to the emerging frequency of repetitive firing, neurons are classified into two types: type 1 and type 2 excitability. Though in mathematical simulations, minor modifications of parameters describing ionic currents can result in transitions between these two excitabilities, empirical evidence to support these theoretical possibilities is scarce. Here we report a joint theoretical and experimental study to test the hypothesis that changes in parameters describing ionic currents cause predictable transitions between the two excitabilities in mesencephalic V (Mes V) neurons. We developed a simple mathematical model of Mes V neurons. Using bifurcation analysis and model simulation, we then predicted that changes in conductance of two low-threshold currents would result in transitions between type 1 and type 2. Finally, by applying specific channel blockers, we observed the transition between two excitabilities forecast by the mathematical model.
Liu
Yihui
Y
Institute of Neuroscience, Fourth Military Medical University, Shaanxi 710032, People's Republic of China. liu.y.hui@gmail.com
Yang
Jing
J
Hu
Sanjue
S
D015761:4-Aminopyridine / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D001683:Biological Clocks / Q000187:drug effects / Q000502:physiology; D002462:Cell Membrane / Q000502:physiology*; D003198:Computer Simulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D007546:Isoquinolines; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009924:Organ Culture Techniques; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D019782:Riluzole / Q000494:pharmacology; D015222:Sodium Channels / Q000187:drug effects / Q000502:physiology; D013194:Staining and Labeling; D009435:Synaptic Transmission / Q000502:physiology*; D014278:Trigeminal Nuclei / Q000166:cytology / Q000502:physiology*
D018691:Excitatory Amino Acid Antagonists; D007473:Ion Channels; D007546:Isoquinolines; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D015222:Sodium Channels; D019782:Riluzole; C017475:lucifer yellow; D015761:4-Aminopyridine