Chapter 5: Communication between Neurons

acetylchonine (ACh)

a neurotransmitter released from cholinergic neurons thats responsible for slowing down heart rate

epinephrine (EP)

a neurotranmitter responsible for speeding up heart rate

norepinephrine (NE) (noradrenaline (NA))

a neurotranmitter released from noradrenergic neurons that replaces EP as the excitatory neurotransmitter

activating systems

sysems that prudce widespread and coordinated influences oh behavior; that is, the parasympathetic and sympathetic nerves in the autonomic nervous system

synaptic cleft

the mintue space separating the axon temrinal and the membrane encasing the tip of an adjacent dentritic spine

postsynaptic membrane

the tip of the dendritic spine that consists largely of protein molecules specialized for receiving chemical messages

presynaptic membane

the membrane of the axon teminal that consists largely of protein molecules

synaptic vesicles (terminal button)

round granules that contain neurotransmitters

storage granules

located in the axon terminals and hold a number of synaptic vesicles

gap junction

where the prejunction and postjunction cell membranes are fused

synthesis

a step in the process of transmitting information across a chemical synapse in which the transmitter is either produced by the cell’s DNA and imported, or its building blocks are manufactured, into the axon terminal

release

a step in the process of transmitting information across a chemical synapse in which the transmitter is transported into the presynaptic membrane and released in response to an action potential

receptor action

a step in the process of transmitting information across a chemical synapse in which the transmitter traverses the synaptic cleft and interacts with receptors on the target cell’s membrane

autoreceptors

self-receptors

inactivation

a step in the process of transmitting information across a chemical synapse in which the transmitter is either drawn back into the presynaptic axon it it breaks down in the synaptic cleft

reuptake

membrane transporter proteins specific to that transmitter may bring it back, or the by-products of degradation, into the presynaptic axon terminal for use

axodendritic synapse

membrane transporter proteins specific to that transmitter may bring it back, or the by-products of degradation, into the presynaptic axon terminal for use

axomuscular synapse

the axon terminal of muscles releases ACh

axosomatic synapse

an axon terminal ends on a cell body

axoaxonic synapse

an axon terminal ends on another axon

axosynaptic synapse

an axon terminal ends on another temrinal

axoextracellular synapses

no specific target but secretes their transmitter chemicals non-specifically into the extracellular fluid

axosecretory synapse

an axon terminal synapse with a tiny blood vessel (capillary) and secretes its transmitter directly into the blood

dendrodendritic synapses

dendrites may send messages to other dendrites

somasomatic

neighboring neurons synchronize their signals

putative transmitter

a chemical that’s suspected of being a neurotransmitter but hasn’t het met all the critieria for proof

Renshaw loop

the circular set of connections between CNS interneurons and synapses on the motor neuron’s cell body

back propagation

sending a essage from the postsynaptic membrane to the presynaptic

small-molecule transmitters

synthesized from dietary nutirents and packaged for use in axon terminals

acetolcholineesterase (AChE)

the enzyme that breaks down acetolycholine (ACh)

dopamine (DA)

an amine and neurotransmitter that plats a role in coordinating movement, attention, learning, and behaviors that are reinforcing

rate-limiting factor

the rate at which dopamine, norepinephine, and epinephrine can be synthesized regardess of how much tyrosine is present or ingested

serotonin (5-HT)

a neurotransmitter that plays a role in regulating mood, aggression, appetite, arousal, pain perception, and respiration

glutamate (Glu)

an excitatory neurotransmitter found in type 1 synapses

gamma-aminobutyric acid (GABA)

an inhibitory neurotransmitter found in type 2 synapses, and also involved in calming the body down

Histamine (H)

a neurotransmitter that controls arousal and waking, and causing the construction of smooth muscles

neuropeptides

multifunctional chains of amino acids that act as neurotransmitters and are made through the translation of mRNA from instructions in the neuron’s DNA

nitric oxide (NO) and carbon monoxide (CO)

water soluble transmitter gases that are synthesized in the cell as needed adn activate metabolic (energy-expending) processes in cells

ionotropic receptor

a receptor that has a binding site for a neurotransmitter and a pore or channel through the membrane

metabotropic receptor

a receptor who’s single protein spans the cell membrane but doesn’t possess a pore of its own through which ions can flow

second messenger

carries a message to other structures within the cell

calcitonin-gene-related peptide (CGRP)

a neuropeptide that acts through second messengers to increase the force with which a muscle contracts

activating systems

activity in the CNS that forms neural pathways that coordinate brain activity through a single neurotransmitter, and controls functions such as motor behavior, arousal, mood, and general brain plasticity; cholinergic, dopaminergic, noradrenergic, andserotonergic systems