Question

What are neurotransmitters, and how can they cause an action potential?

Answer 1

Neurotransmitters are chemical messengers that are endogenous chemicals that enable neurotransmission by transmitting signals across a chemical synapse, which may be between a neuromuscular junction, from one neuron (to another "target" neuron, or gland cell. When an action potential reaches the presynaptic terminal, it causes the release of the neurotransmitter to be from the neuron into the synaptic cleft. This neurotransmitter either helps in exciting the postsynaptic neuron or hinder i.e. inhibits the postsynaptic neuron from firing an own action potential. After traveling across the synaptic cleft, the neurotransmitter attaches with the receptors on the postsynaptic side, depending on the which type of ions are released, i.e. positive (e.g. Na+, K+, Ca+) leading to the firing of an action potential or negative ions (e.g. Cl-) transportation through channels leading to inhibition.