Cognitive Neuroscience: Chapter 2

Front 1

Neurons

Back 1

The basic signaling units, distinguished by their form, function, location and interconnectivity within the nervous system.

Front 2

Soma

Back 2

The cell body of the neuron

Front 3

Dendrites

Back 3

Are (usually) large treelike processes that receive inputs from other neurons at synapses.

Postsynaptic.

Front 4

Axon

Back 4

Transers information to other neurons.

Presynaptic.

Front 5

Saltatory conduction

Back 5

From the Latin ”saltare”, which means ”to jump”. The appearance of the action potential jumping along the myelinated axons from node to node.

Front 6

Spines

Back 6

Little knobs attached by small necks to the surface of the dendrites; synapses are located on these spines.

Front 7

Neurotransmitters

Back 7

The chemical substances that transmit the signal between neurons at chemical synapses.

Front 8

Glial cell

Back 8

Also called neuroglial cell.

A type of cell in the nervous system.

Front 9

Blood-brain barrier (BBB)

Back 9

The astrocytic barrier between neuronal tissue and blood. Plays a vital role in protecting the central nervous system from blood-borne agents or compounds that might unduly affect neuronal activity.

Front 10

Myelin

Back 10

A fatty substance that surrounds the axons of many neurons.

Front 11

Nodes of Ranvier

Back 11

Nodes on an axon where important membrane specializations permit the generation of electrical signals, called action potentials, that are conducted down the axon.

Front 12

Spike-triggering zone

Back 12

The region where long-distance signals, or action potentials, are generated, where spike refers to an action potential.

Front 13

Resting membrane potential

Back 13

The difference in voltage across the neuronal membrane.

Front 14

Ion channels

Back 14

Formed by transmembrane proteins that create pores, actual passageways across the membrane through which ions (charged atoms in solution) of sodium, potassium, and chloride (Na+, K+, and Cl-, respectively) might pass.

Front 15

Permeability

Back 15

The extent to which a channel permits ions to cross the membrane.

Front 16

Permeability

Back 16

The extent to which a channel permits ions to cross the membrane.

Front 17

Electrical gradient

Back 17

The electrical potential that acts on an ion to drive the movement of the ion in one or another direction.

That is, the environment outside becomes more positive than the environment inside the neuron.

Front 18

Equilibrium potential

Back 18

EK = 59.8 log10 (20/400) = -75 mV

Nerve and muscle cells encode information through changes in their membrane potentials.

Front 19

Receptor potentials, Synaptic potentials, Action potentials

Back 19

Electrical currents.

Front 20

Electrotonic conduction

Back 20

The passive and decrease of a charge along a nerve.

Front 21

Depolarizations

Back 21

A passive current which makes the inside of the cell more positive and more likely to generate an action potential.

Front 22

Depolarizations

Back 22

A passive current which makes the inside of the cell more positive and more likely to generate an action potential.

Front 23

Hyperpolarization

Back 23

A passive current which makes the inside of the cell less positive and less likely to generate an action potential.

Front 24

Threshold

Back 24

The value of the membrane potential to which the axon must be depolarized to initiate an action potential.

Front 25

Refractory period

Back 25

The result of membrane hyperpolarization following the depolarization and repolarization of the action potential leaves the neuron in a temporary state in which it is less able to generate an action potential. This refractory period occurs when the membrane potential is even farther from the threshold required for triggering an action potential.

Front 26

Propagation

Back 26

The propagation of action potentials is a continual interplay between electrotonic (passive) and active currents.

Front 27

Receptors

Back 27

Specialized ion channels that mediate signals at synapses.

Front 28

Second messagers

Back 28

Such as Ca+, cyclic nucleotides including cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP), nitric oxide, and other substances.

Involved in indirectly coupled receptors.