Ch. 1 Focus The Mind’s Machine: Foundations of Brain and Behavior

Neuron

A specialized cell that receives, integrates, conducts, and transmits information in the nervous system

Nucleus

Cell structure containing DNA and genetic instructions

Mitochondria

Organelles that produce ATP (cellular energy)

Ribosomes

Structures that synthesize proteins from genetic instructions

Dendrites

Branching neuron structures that receive incoming signals

Dendritic spines

Small protrusions on dendrites that increase synaptic surface area

Cell body (soma)

Neuron region that contains the nucleus and integrates inputs

Axon hillock

Area where the neuron decides whether to fire an action potential

Axon

Long projection that conducts electrical signals away from the soma

Axon collaterals

Branches of an axon that allow communication with multiple targets

Axon terminals

Endpoints of axons that release neurotransmitters

Synapse

Junction where one neuron communicates with another cell

Presynaptic membrane

Part of the synapse that releases neurotransmitters

Synaptic cleft

Small gap between presynaptic and postsynaptic neurons

Postsynaptic membrane

Part of the synapse containing receptors for neurotransmitters

Neurotransmitter

Chemical messenger released at the synapse

Neuroplasticity

The brain’s ability to change synaptic connections with experience

Multipolar neuron

Neuron with many dendrites and one axon; most common type

Bipolar neuron

Neuron with one dendrite and one axon; common in sensory systems

Unipolar (monopolar) neuron

Neuron with a single process that splits into two branches

Glial cells

Non-neuronal cells that support, protect, and insulate neurons

Oligodendrocytes

Glial cells that myelinate axons in the CNS

Schwann cells

Glial cells that myelinate axons in the PNS

Astrocytes

Glial cells that regulate blood flow, synapses, and structural support

Microglia

Immune cells of the nervous system that remove debris and pathogens

Myelin

Fatty insulation around axons that increases conduction speed

Nodes of Ranvier

Gaps in myelin that allow saltatory conduction

Sagittal plane

Divides the brain into left and right halves

Coronal (frontal) plane

Divides the brain into front and back portions

Horizontal plane

Divides the brain into top and bottom sections

Anterior

Toward the front of the brain

Posterior

Toward the back of the brain

Dorsal

Toward the top of the brain

Ventral

Toward the bottom of the brain

Medial

Toward the midline

Lateral

Toward the sides

Ipsilateral

On the same side of the body

Contralateral

On the opposite side of the body

Afferent

Carrying information toward the CNS

Efferent

Carrying information away from the CNS

Gray matter

Brain tissue composed of cell bodies and dendrites; processing

White matter

Brain tissue composed of myelinated axons; transmission

Cerebral cortex

Outer layer of the brain responsible for complex processing

Frontal lobe

Involved in motor control, planning, and decision-making

Parietal lobe

Processes touch and body position

Temporal lobe

Involved in hearing and memory

Occipital lobe

Responsible for vision

Central sulcus

Groove separating frontal and parietal lobes

Sylvian fissure

Groove separating temporal lobe from frontal and parietal lobes

Precentral gyrus

Primary motor cortex

Postcentral gyrus

Primary somatosensory cortex

Somatotopic organization

Ordered mapping of the body onto the cortex

Basal ganglia

Involved in initiating and regulating movement

Cerebellum

Coordinates movement, timing, and motor learning

Brainstem

Controls vital reflexes and basic motor functions

Medulla

Brainstem structure controlling breathing and heart rate

Thalamus

Sensory relay station to the cortex

Hypothalamus

Regulates homeostasis, hormones, and motivation

Limbic system

Network involved in emotion and memory

Amygdala

Processes emotional responses, especially fear

Hippocampus

Critical for learning and memory formation

Neural tube

Embryonic structure that becomes the CNS

Forebrain

Develops into higher cognitive brain structures

Midbrain

Involved in sensory and motor integration

Hindbrain

Controls basic life functions and coordination

Telencephalon

Develops into cerebral hemispheres

Diencephalon

Develops into thalamus and hypothalamus

MRI

Structural imaging technique using magnetic fields

DTI

Imaging technique that maps white matter tracts

fMRI

Measures brain activity via blood oxygen levels

PET

Measures metabolic activity using radioactive tracers

MEG

Measures real-time neural activity via magnetic fields

TMS

Uses magnetic stimulation to causally affect brain activity

Nissl stain

Stains cell bodies in brain tissue

Golgi stain

Stains entire neurons including dendrites and axons

Immunohistochemistry

Labels specific proteins in tissue

Tract tracers

Reveal axonal connections

Brainbow

Labels neurons with multiple colors to map networks