Neurons are cells that send information to the brain. They are a made up of the cell body, dendrites and axons. Dendrites allow a message to go to the cell body, and Axons, conduct the message away from the cell body.

There are three types of neurons: Inter neuron (As shown below), motor-neuron, sensory-neuron

The neurons communication method is called Action Potential. It is an electrochemical signal that comes from a nerve impulse.  It starts with an electrical change that moves from the cell body, through the axon. The movement is caused by a positive ions causing a chain reaction throughout the axons.  This is called Depolarization. It is an message that stimulates the axon when sodium ions flow into the axon and changes the axon segment to negative. Then flowing through the axon with it action potential. After the axon re polarizes  with channels let the K+ ions to leave the axon, then the charge returns to its original charge.

Synapse:

A synapse has, the ends of dendrites receiving the neuron, tips of terminal branches of axon and a synaptic gap, or a tiny gap between neurons.

An Axon terminal button produces Neurotransmitter, it keeps NT in the synaptic vesicles, and recycle NT. When Action Potential reaches the end of the axon, is causes the vesicles to give away the neurotransmitters through the synaptic gap and reaches the receptors on the receiving neuron.

After receiving the neuron the dendrite determines the NT function as either excitatory, or inhibitory. Excitatory, stimulates the AP on the receiving neuron and inhibitory represses AP.