Brain Bio aditi

Refractory period

The minimum length of time after an action potential during which another action potential cannot begin.

Action potential

A brief change in a neuron's electrical charge.

Adoption studies

Research studies that assess hereditary influence by examining the resemblance between adopted children and both their biological and their adoptive parents

Agonist

A chemical that mimics the action of a neurotransmitter.

Antagonist

A chemical that opposes the action of a neurotransmitter.

Autonomic nervous system (ANS)

The system of nerves that connect to the heart, blood vessels, smooth muscles, and glands.

Axon

A long, thin fiber that transmits signals away from the neuron cell body to other neurons, or to muscles or glands.

Central nervous system (CNS)

The brain and the spinal cord.

Cerebral cortex

The outer layer of the cerebrum - humans have largest

Corpus callosum

The structure that connects the two cerebral hemispheres.

Dendrites

Branchlike parts of a neuron that are specialized to receive information.

Electroencephalograph (EEG)

A device that monitors the electrical activity of the brain over time by means of recording electrodes attached to the surface of the scalp.

glial cells

Found throughout the nervous system that provide various types of support for neurons.

Hypothalamus

A structure found near the base of the forebrain that is involved in the regulation of basic biological needs.

Lesioning

Destroying a piece of the brain.

Mirror neurons

Neurons that are activated by performing an action or by seeing another monkey or person perform the same action. Frontal lobe

Neurotransmitters

Chemicals that transmit information from one neuron to another.

Parasympathetic NS

The branch of the autonomic nervous system that generally conserves bodily resources - calm

Peripheral nervous system

All those nerves that lie outside the brain and spinal cord.

Resting potential

The stable, negative charge of a neuron when it is inactive.

Reuptake

A process in which neurotransmitters are sponged up from the synaptic cleft by the presynaptic membrane.

Soma or cell body

Contains the nucleus and much of the chemical machinery common to most cells.

Somatic NS

The system of nerves that connect to voluntary skeletal muscles and to sensory receptors.

Split-brain surgery

A procedure in which the bundle of fibers that connects the cerebral hemispheres (the corpus callosum) is cut to reduce the severity of epileptic seizures.

Sympathetic NS

The branch of the autonomic nervous system that mobilizes the body's resources for emergencies.

Synapse

A junction where information is transmitted from one neuron to the next.

Terminal buttons

Small knobs at the end of axons that secrete chemicals called neurotransmitters.

Transcranial magnetic stimulation (TMS)

A technique that permits scientists to temporarily enhance or depress activity in a specific area of the brain.

Twin studies

A research design in which hereditary influence is assessed by comparing the resemblance of identical twins and fraternal twins with respect to a trait.

Dopamine

Excitatory - responsible for pleasure, movement, learning, attention - low levels, Parkinson's

Serotonin

Inhibitory - Mood, hunger, sleep, arousal - low levels, depression and anxiety

GABA

Balances excitatory messages - Contributes to regulation of anxiety

Glutamate

Excitatory - Thinking, memory, learning - strengthening neural connections, high levels - agitation and memory loss

Norepinephrine

Excitatory - Alertness & arousal Increasing heartbeat, arousal, memory, learning, and eating

Acetylcholine

Excitatory - Muscle action/contractions; learning/memory - Messenger at every junction between motor neuron & skeletal muscle - low levels, paralysis, Alzheimers

Endorphins

Inhibitory - "morphine within" - natural opiates, pain control and pleasure

Frontal Lobe

planning, judgment, memory, reasoning, abstract thinking, movement (motor cortex) *mirror neurons

Parietal Lobe

Important area governing spatial awareness and navigation - information about touch (sensory cortex), Left hemisphere involved in mathematics, reading, writing and understanding symbols.

Temporal Lobe

hearing (auditory cortex), Wernicke's for language

Occipital Lobe

visual information (visual cortex)

Broca's Aphasia

Damage that makes speech very slow, slurred and labored, no comprehension problems

Wernicke's Aphasia

Damage where speech is incomprehensible - patients have great difficulty understanding - Speech is NOT slurred

Lateralization/contralateral control

hemispheres control the opposite sides of the body

hippocampus

creates, integrates, consolidates memories

Amygdala

Damage to this region leads to decrease in fear, aggression, and sexual desire

hypothalamus

Helps to govern endocrine system and controls maintenance functions - eating and drinking

Cerebellum

enables nonverbal learning, coordinates voluntary movements

Reticular formation

regulates sleep, wakefulness, and levels of arousal - damage would lead to coma

Medulla

Controls heartbeat and breathing

CAT Scan

Provides structural imaging using Xrays

fMRI

Provides functional imaging of active brain areas using magnetic fields

Plasticity

the ability of the brain to form and reorganize synaptic connections, compensate for damage

Substance P

A neurotransmitter that is involved in the transmission of pain messages to the brain.