NeuronSignalTransmissionResearch

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Neural Signal Transmission Research

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Direction of signal transmission

  • nerve impulses can propagate in either direction along axons
  • neural signals are conveyed from neuron to another cell in one direction across synapse
  • nerve impulses in postsynaptic cell do not normally have substantial effect on presynaptic cell
  • information flow in dendrites is generally in form of synaptic currents, which affect membrane potential at the action potential trigger zone in axon hillock where a nerve impulse may be triggered
  • action potential then conducts distally along axon, but also backward (antidromically) into dendrites

Accumulating action potential

  • there is finite number of incoming spikes emitted (spike train) before postsynaptic cell fires

Refractory period

  • refractory period is transient phase just after firing during which it is either impossible or difficult to communicate with cell
  • can be decomposed into two phases:
    • absolute refractory period, which is constant period of time corresponding loosely to hyperpolarization of neuron during which is it impossible to excite or inhibit cell no matter how great stimulating current applied is
    • immediately after begins relative refractory period during which initiation of second action potential is inhibited but still possible (lasts 2ms)