Neuroscience: Exploring the Brain Chapter 2

neuron

The information-processing cell of the nervous system; also called nerve cell.

Franz Nissl, histology

Who discovered Nissl stains and what was his specialty?

glial cell

A support cell in the nervous system.

histology

The microscopic study of the structure of tissues.

Nissl stain

A class of basic dyes that stain the somata of neurons

cytoarchitecture

The arrangement of neuronal cell bodies in various parts of the brain.

Golgi stain

A method of staining brain tissue that shows neurons and all of their neurites.

cell body

The central region of the neuron containing the nucleus; also called soma or perikaryon.

soma

The central region of the neuron containing the nucleus; also called cell body or perikaryon.

perikaryon

The central region of the neuron containing the nucleus; also called soma or cell body.

neurite

A thin tube extending from a neuronal cell body; the two types are axons and dendrites.

axon

A neurite specialized to conduct nerve impulses, or action potentials, normally away from the soma.

dendrite

A neurite specialized to receive synaptic inputs from other neurons.

neuron doctrine

The concept that the neuron is the elementary functional unit of the brain and that neurons communicate with each other by contact, not continuity.

cytosol

The watery fluid inside a cell.

organelle

A membrane-enclosed structure inside a cell; examples are the nucleus, mitochondrion, endoplasmic reticulum, and Golgi apparatus.

cytoplasm

Cellular material contained by the cell membrane, including the organelles but excluding the nucleus.

nucleus

(1) The roughly spherical organelle in a cell body containing the chromosomes.
(2) A clearly distinguishable mass of neurons, usually deep in the brain.

chromosome

A structure in the cell nucleus containing a single linear thread of DNA.

DNA (deoxyribonucleic acid)

A double-stranded molecule constructed from four nucleic acids that contains the genetic instructions for a cell.

gene

A unit of heredity; a sequence of DNA that encodes a single polypeptide or protein.

gene expression

The process of transcribing the information from a gene into a functional gene product

protein

A polymer of amino acids strung together by peptide bonds.

protein synthesis

The assembly of protein molecules in the cell's cytoplasm according to genetic instructions.

mRNA (messenger ribonucleic acid)

A molecule constructed from four nucleic acids that carries the genetic instructions for the assembly of a protein from the nucleus to the cytoplasm.

transcription

The process of forming a messenger RNA molecule according to genetic instructions encoded in DNA.

promoter

A region of DNA that binds RNA polymerase to initiate gene transcription.

transcription factor

A protein that regulates the binding of RNA polymerase to a gene promoter.

RNA splicing

The process by which introns, the regions of a primary RNA transcript that are not used to code protein, are removed.

amino acid

A chemical building block of protein molecules, containing a central carbon atom, an amino group, a carboxyl group, and a variable R group.

translation

The process of synthesizing a protein molecule according to genetic instructions carried by a messenger RNA molecule.

ribosome

A cellular organelle that assembles new proteins from amino acids according to the instructions carried by messenger RNA.

rough endoplasmic reticulum (rough ER)

A membrane-enclosed cellular organelle with ribosomes attached to its outer surface; a site of synthesis for proteins destined to be inserted into membrane or to be enclosed by membrane.

polyribosome

A collection of several ribosomes floating freely in the cytoplasm.

smooth endoplasmic reticulum (smooth ER)

A membrane-enclosed cellular organelle that is heterogeneous and performs different functions in different locations.

Golgi apparatus

An organelle that sorts and chemically modifies proteins that are destined for delivery to different parts of the cell.

mitochondrion

An organelle responsible for cellular respiration.

adenosine triphosphate (ATP)

The molecule that is the cell's energy source.

neuronal membrane

The barrier, about 5 nm thick, that separates the inside of a nerve cell from the outside; consists of a phospholipid bilayer with proteins embedded in it; encloses the intracellular organelles and vesicles.

cytoskeleton

The internal scaffolding that gives a cell its characteristic shape; consists of microtubules, neurofilaments, and microfilaments.

microtubule

A polymer of the protein tubulin, forming a straight, hollow tube 20 nm in diameter.

microfilament

A polymer of the protein actin, forming a braided strand 5 nm in diameter; a component of the cytoskeleton.

neurofilament

A type of intermediate filament found in neurons, 10 nm in diameter; an important component of the neuronal cytoskeleton.

axon hillock

A swelling of the axon where it joins the soma.

axon collateral

Axons that can send a branch back toward its own cell's soma.

axon terminal

The end region of an axon, usually a site of synaptic contact with another cell; also called terminal bouton or presynaptic terminal.

terminal bouton

The end region of an axon, usually a site of synaptic contact with another cell; also called axon terminal.

synapse

The region of contact where a neuron transfers information to another cell.

terminal arbor

Branches at the end of an axon terminating in the same region of the nervous system.

innervation

The provision of synaptic input to a cell or collection of cells.

synaptic vesicle

A membrane-enclosed structure, about 50 nm in diameter, containing neurotransmitter and found at a site of synaptic contact.

synaptic cleft

The region separating the presynaptic and postsynaptic membranes of neurons.

synaptic transmission

The process of transferring information from one cell to another at a synapse.

neurotransmitter

A chemical released by a presynaptic element upon stimulation that activates postsynaptic receptors.

axoplasmic transport

The process of transporting materials up or down an axon.

anterograde transport

Axoplasmic transport from a neuron's soma to the axon terminal.

retrograde transport

Axoplasmic transport from an axon terminal to the soma.

dendritic tree

All the dendrites of a single neuron.

sensory receptor

(1) A specialized protein that detects chemical signals, such as neurotransmitters, and initiates a cellular response.
(2) A specialized cell that detects environmental stimuli and generates neural responses.

dendritic spine

A small sac of membrane that protrudes from the dendrites of some cells and receives synaptic input.

unipolar neuron

A neuron with a single neurite.

bipolar neuron

A neuron with two neurites.

multipolar neuron

A neuron with three or more neurites.

stellate cell

A neuron characterized by a radial, starlike distribution of dendrites.

pyramidal cell

A neuron characterized by a pyramid-shaped cell body and elongated dendritic tree; found in the cerebral cortex.

spiny neuron

A neuron with dendritic spines.

aspinous neuron

A neuron lacking dendritic spines.

primary sensory neuron

A neuron specialized to detect environmental signals at the body's sensory surfaces.

motor neuron

A neuron that synapses on a muscle cell and causes muscle contraction.

interneuron

Any neuron that is not a sensory or motor neuron; also describes a CNS neuron whose axon does not leave the structure in which it resides.

astrocyte

A glial cell in the brain that supports neurons and regulates the extracellular ionic and chemical environment.

oligodendroglial cell

A glial cell that provides myelin in the central nervous system.

Schwann cell

A glial cell that provides myelin in the peripheral nervous system.

myelin

A membranous wrapping, or sheath, around axons provided by oligodendroglia in the central nervous system and Schwann cells in the peripheral nervous system.

node of Ranvier

A space between two consecutive myelin sheaths where an axon comes in contact with the extracellular fluid.

ependymal cell

A type of glial cell that provides the lining of the brain's ventricular system.

microglial cell

A type of cell that functions as a phagocyte in the nervous system to remove debris left by dead or dying neurons and glia.

Microtubules

___________ are a component of the cytoskeleton and plays an important role in axoplasmic transport.

adenosine diphosphate (ADP)

What does the hydrolysis of ATP produce?

Mitochondria

What part of the cell converts ADP back in to ATP?

Oxidation of food

How does the mitochondria gain the energy to convert ADP?

Camillo Golgi, histologist

Who discovered Golgi staining? What kind of scientist was he?

schwann, oligodendroglial, astrocyte and microglia

What are the four categories of glial cells?