Harmony or “Homeostasis”
A properly functioning brain is a study in harmony or “homeostasis.” The brain is composed of about a hundred billion neurons. Each neuron communicates with other neurons through the exchange of tiny molecules called neurotransmitters.
Groups of neurons with specialized functions are organized into the brain’s multiple structures, all of which must maintain internal balance among their constituent neurons while simultaneously balancing with other brain structures in order to function optimally.
The brain has systems to keep every system and every component of each system balanced. Neurotransmitters, for example, must be boosted at appropriate times but not at others. They need to be activated enough but not too much. The brain contains mechanisms to accomplish that.
The brain is engineered to anticipate malfunction — as if designed with Murphy’s Law in mind. There are built-in networks to detect and remedy breakdowns and restore system harmony, through the use of real-time feedback loops that can not only recognize anomalies but trigger corrective response.
The brain’s built-in feedback and corrective systems keep the interplay between different neurotransmitters and competing structures in proper harmony or homeostasis. When the brain is not able to maintain stasis, disease results, with concomitant behaviors that can range from the subtle to the psychotic, depending on the nature and severity of the imbalance.
Addiction researchers say drug abuse shifts the balance normal between emotional and rational systems in favor of the emotional, because of the outsized psychological payoff drugs provide to addicts. Thus, understanding how a balanced brain can be “switched” into one that is pathologically unbalanced lies at the heart of neuroscientific research into addiction.