Neurotransmitters: Functions, Disorders, and Effects in Psychology

Acetylcholine (Ach)

Enables muscle action, learning and memory

Alzheimer's disease, ACH-producing neurons deteriorate

Dopamine

Influences movement, learning, attention, and emotion.

Excess dopamine receptor activity linked to schizophrenia. Starved of dopamine, the brain produces the tremors and decreased mobility of Parkinson's disease.

Serotonin

Affects mood, hunger, sleep and arousal.

Undersupply linked to depression; Prozac and some other antidepressant drugs raise serotonin levels.

Norepinephrine

Helps control alertness and arousal.

Undersupply can depress mood.

GABA

(gamma-aminobutyric acid)

A major inhibitory neurotransmitter.

Undersupply linked to seizures, tremors, and insomnia.

Glutamate

A major excitatory neurotransmitter; involved in memory.

Oversupply can overstimulate brain, producing migraines or seizures (which is why some people avoid MSG, monosodium glutamate, in food).

central nervous system

brain and spinal cord

peripheral nervous system

somatic nervous system

autonomic nervous system:

- sympathetic nervous system

- parasympathetic nervous system

dendrites

electrochemical

receives messages from other cells

cell body (soma)

the cell's life support center

axon

passes messages away from the cell body to other neurons, muscles, or glands

neural impulse

action potential

electrical signal traveling down the axon

myelin sheath

covers the axon of some neurons and helps speed neural impulses

terminal branches of axon

form junctions with other cells

Interneuron/afferent neuron

bipolar neuron

Sensory neuron

unipolar neuron

Motor/Efferent neuron

multipolar neuron

Agonists

Mimic the action of neurotransmitters

Antagonists

Oppose the effects of a neurotransmitter, or block its effects

Action Potential

Changes in electrical voltage

Produces a neutral impulse

Neurotransmitter

Molecules are released into the synaptic cleft and bind to receptor sites on the receiving neuron

Cellular Structure

46 Chromosomes = all cells except reproductive

23 chromosomes in sperm/egg cells

Found in the Nucleus contains DNA

Heritability

It tells us NOTHING about individuals

It is an ESTIMATE of variation in a population

It is a correlation between nature and nurture in a population

Twin Studies

identical twins: 1 egg, 1 sperm, same placenta

fraternal twins: 2 eggs, 2 sperms, different placenta

Somatic nervous system

controls conscious body movements through skeletal muscles and processes sensory information, including touch, sound, sight, taste, and smell

sympathetic nervous system

a division of the autonomic nervous system responsible for the body's "fight-or-flight" response to stress, danger, or physical activity

parasympathetic nervous system

a division of the autonomic nervous system responsible for the body's "rest and digest" functions, promoting relaxation and maintaining normal daily activities like digestion, salivation, and a reduced heart rate