The human brain is the most complex organ in the body. In brief, the brain regulates your basic body functions; enables you to interpret and respond to everything you experience; and shapes your thoughts, emotions, and behavior.
The brain is made up of many parts that all work together as a team. Different parts of the brain are responsible for coordinating and performing specific functions.
Brain areas affected by drug use
The brain stem controls basic functions critical to life, such as heart rate, breathing, and sleeping.
The limbic system contains the brain’s reward circuit—it links together a number of brain structures that control and regulate our ability to feel pleasure. Feeling pleasure motivates us to repeat behaviors such as eating, actions that are critical to existence. The limbic system is activated when we perform these activities and also by drugs. In addition, the limbic system is responsible for our perception of other emotions, both positive and negative, which explains the mood-altering properties of many drugs.
The cerebral cortex is divided into areas that control specific functions. Different areas process information from our senses, enabling us to see, feel, hear, and taste. The front part of the cortex, the frontal cortex, is the thinking center of the brain; it powers our ability to think, plan, solve problems, and make decisions.
How the brain communicates
The brain is a communications center consisting of billions of neurons, or nerve cells. Networks of neurons pass messages back and forth to different structures within the brain, the spinal column, and the peripheral nervous system. These nerve networks coordinate and regulate everything we feel, think, and do.
Neuron to Neuron: Each nerve cell in the brain sends and receives messages in the form of electrical impulses. Once a cell receives and processes a message, it sends it on to other neurons.
Neurotransmitters - The Brain’s Chemical Messengers: The messages are carried between neurons by chemicals called neurotransmitters. (They transmit messages between neurons.)
Receptors - The Brain’s Chemical Receivers: The neurotransmitter attaches to a specialised site on the receiving cell called a receptor. A neurotransmitter and its receptor operate like a “key and lock,” an exquisitely specific mechanism that ensures that each receptor will forward the appropriate message only after interacting with the right kind of neurotransmitter.
Transporters - The Brain’s Chemical Recyclers: Located on the cell that releases the neurotransmitter, transporters recycle these neurotransmitters (i.e., bring them back into the cell that released them), thereby shutting off the signal between neurons.
￼How brain cells communicate
- To send a message a brain cell releases a chemical (neurotransmitter) into the space separating two cells called the synapse.
- The neurotransmitter crosses the synapse and attaches to proteins (receptors) on the receiving brain cell.
- This causes changes in the receiving brain cell and the message is delivered.