1.3 Neurons & Neural Firing

1.3.A.1
Two common types of neural cells in the brain are neurons (neural cells that transmit information) and glial cells (cells that provide structure, insulation, communication, and waste transport). These types of cells form the basis of the nervous system and are the building blocks of all behavior and mental processes.

1.3.A.2
In the spinal cord, the reflex arc demonstrates how neurons within the central and peripheral nervous systems work together to respond to stimuli. Three types of neurons work together in the spinal cord to create a reflex arc: sensory neurons, motor neurons, and interneurons.

1.3.B.1
The process of neural transmission most commonly occurs in an orderly, systematic way and involves the all-or-nothing principle, depolarization, refractory period, resting potential, reuptake, and threshold. Disruptions to this process could lead to disorders such as multiple sclerosis or myasthenia gravis.

1.3.B.2
Each neurotransmitter has specific function(s) related to behavior and mental processes, which may depend on the neurotransmitter’s location in the nervous system. Neurotransmitters generally communicate either excitatory (making an action potential more likely) or inhibitory (making an action potential less likely) messages. Neurotransmitters related to behavior and mental processes for study in AP Psychology are limited to dopamine, serotonin, norepinephrine, glutamate, GABA, endorphins, substance P, and acetylcholine.

1.3.B.3
Outside of the nervous system, hormones perform actions similar to neurotransmitters. Hormones related to behavior and mental processes for study in AP Psychology are limited to adrenaline, leptin, ghrelin, melatonin, and oxytocin.

1.3.C.1
Psychoactive drugs can influence neurotransmitter function in various ways throughout the neural communication process. Some act as agonists, which encourage neural firing. Some act as antagonists, which discourage neural firing. Some act as reuptake inhibitors, which block the reabsorption of neurotransmitters back into the cell.

1.3.C.2
Psychoactive drugs have psychological and physiological effects.

1.3.C.2.i
Stimulants, such as caffeine and cocaine, typically cause increased neural activity.

1.3.C.2.ii
Depressants, such as alcohol, typically cause decreased neural activity.

1.3.C.2.iii
Hallucinogens, such as marijuana, typically cause distortions in perception and/or cognition.

1.3.C.2.iv
Opioids, such as heroin, typically act as pain relievers.

1.3.C.3
Psychoactive drug use can lead to tolerance and/or addiction. Addiction can create significant withdrawal symptoms if the psychoactive drugs are no longer consumed.