Free energy inherent in the electrochemical gradient for sodium across membranes can be used to drive uphill processes such as CoTransport. When ion channels open during an action potential, a decrease in membrane capacitance occurs. To function properly, both electrical and chemical synapses require an inward calcium current in the presynaptic terminal. The neurotransmitter Acetylcholine can be excitatory or inhibitory. Sodium channels are found in high density at the axon hillock and at the Nodes of Ranvier.
Invertebrates use myelin to increase action potential conduction velocity.
In Myasthenia Gravis, neuromuscular junctions of patients become subject to depression with repeated stimulation because their acetylcholine receptors are blocked and cross linked by antibodies. Electrical synaptic transmission was first demonstrated between the Lateral Giant neuron and the Motor Giant neuron in the crayfish. In real animal cells, electrochemical gradients across the membrane are maintained . All the above 3. Recording extracellularly in two places on a myelinated axon you find that it takes 1 millisecond for an action potential to travel between the two electrodes.