Neighbouring neurons send each other chemical signals across the gap (synapses) which separates them
Neurotransmitter: Brain chemicals released from synaptic vesicles from one neuron to another. There are two types of neurotransmitters, these can be separated into two types: excitatory and inhibitory.
Excitation: When a neurotransmitter (like adrenaline) increases a positive charge it is more likely to pass on an electric pulse to another neuron (these often stimulate the body)
• Inhibition: When a neurotransmitter (like serotonin) increases a negative charge it is less likely to pass on an electrical impulse to another neuron (these often calm the body down)