| Abstract [eng] |
Motoneurons transform synaptic inputs in to sequences of action potentials (AP). This transformation can be investigated as dependence of spike frequency on injected current (f-I relation). Generation of AP and firing-pattern are strongly influenced by a number of voltage dependant ion conductance. The role of persistent sodium current (INaP) on f-I relation was investigated. The investigation was performed on motoneurons from adult turtle (Chrysemys scripta elegans) spinal cord. We found that INaP decreased the reobase and decreased the steepness of f-I relation. It was found, that during scratching (when neurons network are active) the conductance of motoneurons was strongly increased. We investigated how high conductance affects reobase and f-I relation. The conductance of motoneurons was increased by bath applied muscimol– an agonist of GABAA receptors. We found that increased motoneuron conductance increased reobase and decreased the steepness of f-I relation. |
