Psych 3 - Neural Communication

Glia

One of two cell types that make up the nervous system; provide scaffolding, help neurons align, provide insulation, transport nutrients/waste, and mediate immune responses

Neurons

Interconnected information processors essential for all nervous system tasks

Soma (Cell Body)

Contains the nucleus of the neuron

Dendrites

Branching extensions from the soma that serve as input sites where signals are received from other neurons

Axon

Major extension from the soma that transmits electrical signals to terminal buttons

Terminal Buttons

End points of axons that contain synaptic vesicles

Synaptic Vesicles

House neurotransmitters (chemical messengers of the nervous system)

Myelin Sheath:

Coating on axons that acts as insulation, increasing signal transmission speed

Synapse

Very small space between two neurons where communication occurs

Receptors

Proteins on cell surfaces where neurotransmitters attach; have specific shapes matching specific neurotransmitters

Semipermeable Membrane

Neuron's outer surface that allows smaller/uncharged molecules through while stopping larger/charged molecules

Membrane Potential

Difference in electrical charge across the neuronal membrane

Resting Potential

State of readiness when the neuron membrane's potential is held between signals

Threshold of Excitation

Specific charge level that must be reached for a neuron to become active

Depolarization

Process when the cell's charge becomes positive or less negative

Action Potential

Electrical signal that moves from cell body down the axon to terminals; the positive spike in membrane potential

Repolarization

Process when the cell quickly returns toward resting potential as potassium ions leave

Hyperpolarization

When the cell becomes slightly more negative than resting potential

All-or-None Phenomenon

Incoming signals are either sufficient or insufficient to reach threshold; action potentials propagate at full strength

Reuptake

Process where excess neurotransmitters are reabsorbed back into the neuron

Psychoactive Drugs

Can act as agonists or antagonists for neurotransmitter systems

Agonists

Chemicals that mimic a neurotransmitter at the receptor site, strengthening its effects

Antagonists

Block or impede normal neurotransmitter activity at the receptor

Reuptake Inhibitors

Prevent unused neurotransmitters from being transported back to the neuron

Mood Disorders

Conditions where a person experiences severe disturbances in mood and emotion

Psychological Disorder

Condition characterized by abnormal thoughts, feelings, and behaviors

Psychopathology

Study of psychological disorders, including symptoms, causes (etiology), and treatment

Major Depressive Disorder

Includes depressed mood most of the day, nearly every day, and loss of interest/pleasure in usual activities

Seasonal Pattern

Depression symptoms occurring only during particular times of year

Peripartum Onset (Postpartum Depression)

Major depression during pregnancy or four weeks following childbirth

Persistent Depressive Disorder

Depressed moods most of the day, nearly every day, for at least two years

Bipolar Disorder

Mood states that vacillate between depression and mania

Unipolar

Persistently sad mood (in contrast to bipolar)

Manic Episode

Distinct period of abnormally elevated, expansive, or irritable mood with increased activity/energy lasting at least one week

Flight of Ideas

Rapid switching from one topic to another during manic episodes

Cortisol

Stress hormone released by the neuroendocrine system; often elevated in depressed individuals