What is the neurobiological component of addiction?

Neuro means brain and Biology means internal function of the brain , spinal cord and nerves. The study of nervous system and its functions is known as neurobiology . Nervous system include Central nervous system and Peripheral nervous system in which CNS include Brain & its parts like hind brain that are responsible for arousal and several vital functions , mid brain responsible for experiences, reactions and memory, forebrain responsible for all executive functions  and Spinal cord whereas PNS is further divided into two Autonomic nervous system and Somatic nervous system . The basic part of Nervous system is Neurons and Synapses where neurons are the information carrier and synapses are the junctions  from are transmitted from where message or the impulses that are called Neurotransmitters are transmitted from 1 neuron to another