"3D animation of a neuron and an action potential. Ion channels in the soma open and allow an increase in the intracellular voltage. Once the voltage reaches a threshold, an action potential is generated, which travels the length of the axon and passes into the terminals. The voltage in the terminals stimulate the release of neurotransmitters which cross the synapse, opening ion channels in dendrites of the post-synaptic neuron and increasing the voltage of the second neuron."
Two videos, the first shows a duck imprinting itself on a puppy. The second shows Konrad Lorenz demonstrating the effect where various ducklings imprint themselves on him.