0407 excitation, inhibition and neuromodulation Flashcards
• Know what renders a synaptic response excitatory or inhibitory • Understand how ion fluxes influence the excitability of the synapse • Appreciate that neurotransmitters excite, inhibit or modulate • Understand the synthesis, some of the actions, and the degradation of Glu, GABA and ACh • Be familiar with the notions of ionotropic and metabotropic receptors • Be aware of the major receptors types in the brain
What is the characteristic synapse of NMJ
Excitatory
What are the 3 types of synapses that neuron-neurons are capable of
Excitatory, inhibitory and modulatory
What is the end function of an excitatory, inhibitory and modulatory synapse
Excitatory - depolarisation of membrane. Inhibitory - hyperpolarisation of membrane. Modulatory - brightens or dampens resposnes to other NT
List two common excitatory NT
Glutamate and aspartate
What type of receptor do most excitatory and inhibitory synapse use
Ionotropic (aka ligand-gated receptors)
List two common excitatory NT
GABA (gamma aminobutyric acid) and glycine
What is EPSP and IPSP and what synapse are they caused by
EPSP = excitatory post-synaptic potential = excitatory synapse. IPSP =inhibitory post-synaptic potential = inhibitory synapse
List some examples of modulatory NT
Any hormone, amine group, etc (dopamine, serotonin, histamine)
What molecules do excitatory and inhibitory synapses involve (influx and eflux)
Excitatory synapses generally influx of Na+ or K+. Inhibitory synapses generally influx of Cl-
What are the 3 ways which NT signal achieves it’s effect in the post synaptic membrane and cell
Ligand-gated channel (1 boudn receptor = 1 open channel). Membrane delimited pathway (1 bound receptor leads to 10-20 G proteins which activate local channels on membrane). Amplification by signal cascade (signal cascade resulting in signally throughout cytoplasm)
Provide an example of a common excitatory NT, it’s location, the enzyme that makes it and one receptor
Glutamate (Central Nervous System). it is made by glutaminase and can be bound to AMPA receptor
Provide an example of a common inhibitory NT, it’s location, the enzyme that makes it and one receptor
GABA (found mostly in NT). It is made by Glutamic acid decarboxylase (GAD decarboxylase) and can be bound to GABA (A or B) receptor channel
Is acetylcholine an excitatory or inhibitory neurotransmitter
It can be both
