3.2.1 Chemical Events At The Synapse 2 Flashcards
(29 cards)
____ ____ in the spinal-cord have one branch to the muscles, where they release acetylcholine, and another branch to other spinal-cord neurons, where they release both acetylcholine and glutamate.
Motor neurons
A combination of transmitters makes the neurons message more ____, such as brief excitation followed by slight but prolonged inhibition.
complex
Although a neuron releases only a limited number of neurotransmitters, it may receive and respond to many neurotransmitters at different ____.
synapses
The effect of a neurotransmitter depends on its receptor on the postsynaptic cell. When the neurotransmitter attaches to its receptor, the receptor may open a channel – exerting an ____ effect – or it may produce a slower but longer effect – a ____ effect.
ionotropic : metabotropic
Imagine a paper bag that is twisted shut at the top. If you untwist it, the opening grows larger to that something can go into or come out of the bag. An ____ ____ is like that.
ionotropic receptor
When the neurotransmitter binds to an ionotropic receptor, it twists the receptor enough to open a ____ ____, which is shaped to let a particular type of ion pass through.
central channel
Channels controlled by neurotransmitter are _____ or _____ channels. That is, when the neurotransmitter attaches, it opens a channel. (A ligand is a chemical that binds to another chemical.)
transmitter-gated or ligand-gated
Ionotropic effects are well suited to convey ____ information, ____ information, and anything else that needs to be updated as quickly as possible.
visual : auditory
Most of the brains excitatory ionotropic synapses use the neurotransmitter ____.
glutamate
Most of the inhibitory ionotropic synapses use the neurotransmitter GABA (__________), which opens chloride gates, enabling chloride ions, with the negative charge, to cross the membrane into the cell more rapidly than usual.
gamma-amino-butyric acid
____ is another common inhibitory transmitter, found mostly in the spinal cord.
Glycine
____, another transmitter at many ionotropic synapses, is excitatory in most cases.
Acetylcholine
At other receptors, neurotransmitters exert ____ ____ by initiating sequence of metabolic reactions that are slower and longer lasting than ionotropic effects.
metabotropic effects
Metabotropic synapses use many neurotransmitters, including ____, ____, and ____… and sometimes glutamate and GABA too.
dopamine, norepinephrine, and serotonin
When neurotransmitters attaches to metabotropic receptor, it ____ the receptor protein that goes through the membrane of the cell.
bends
The other side of the bent receptor is attached to a ____ – that is, a protein coupled to ____ ____ (GTP), an energy storing molecule.
G protein : guanosine triphosphate
Bending the receptor protein ____ that G protein, which is then free to take energy elsewhere in the cell.
detaches
Metabotropic synapses are better suited for more enduring effects such as ____, ____, and ____, where exact timing isn’t important anyway.
taste, smell, and pain
Metabotropic synapses are also important for many aspects of ____, ____, ____, and ____ – again, functions that arise more slowly and last longer than visual or auditory stimulus.
arousal, attention, pleasure, and emotion
Research is often refer to neuropeptides as ____, because they have several properties that set them apart from other transmitters.
neuromodulators
Where as the neuron synthesises most other neurotransmitters in the presynaptic terminal, it synthesises neuropeptides in the ____ ____ and then slowly transports them to other parts of the cell.
cell body
Whereas other neurotransmitters are released at the axon terminal, neuropeptides are released mainly by ____.
dendrites
Neurons containing neuropeptides do not often release them, but when they do, they release ____ amounts.
substantial
Neuropeptides are important for ____, ____, ____ ____, and other long-term changes in behaviour and experience.
hunger, thirst, intense pain
