Ch. 4 Module 2 Flashcards
What is the most common excitatory neurotransmitter in the CNS?
Glutamate
What is the most abundant inhibitory neurotransmitter in the CNS?
GABA
What are GABA A receptors?
They are inotropic and have chloride channels.
What are GABA B receptors?
They are metabotropic and they open potassium channels in the membrane.
What are the 2 subclasses of monamines:
indoleamines & catecholamines
catecholamines include
dopamine, norepinephrine
What are catecholamines broken down by?
COMT & MAO
Indoleamines include, and are broken down by what?
Serotonin, and is only broken MAO
What are the rule for determining if a substance is a neurotransmitter?
- Present in presynaptic vesicles
- Must occur naturally within system
- Must be released when an action potential invades the terminal.
- produce a PSP when applied
- Should have specific receptor in post synaptic membrane
- reception should lead to change in membrane potential of dendritic spine
- some specific mechanism should exist for inactivation of substance once released
- sam effect for stimulating nerve and releasing chemical on dendritic spine.
What are amino acid neurotransmitters?
simple molecules and do not need a synthesis pathway
What are the 2 amino acid neurotransmitters?
Glutamate & GABA
Glutamate
- is a very common chemical in the brain
- it is produced in the Krebs cycle
- all cells have glutamate
- it is excitatory
- crucial in the process of long term potentiation
What are the 3 types of iontropic glutamate receptors?
AMPA
NMDA
Kainate
AMPA
- responds strongly to the drug
- has a sodium channel
- generates an EPSP
Kainate
- has a sodium channel
- responds to a neurotoxin called kainic acid that is obtained from sea weed.
NMDA
- has a calcium channel
- is crucial in LTP
- NMDA receptor is blocked at RP by magnesium ion
Acetylcholine
- is found in skeletal muscle synapses
- is the most common excitatory neurotransmitter in the PNS
- heavily involved in Alzheimer’s disease
What are the two types of receptors for ACh?
Nicotine (PNS) & Muscarine (CNS)
Explain what the torpedo fish does?
- the torpedo fish generated electric shocks to stun prey and deter predators
What are monoamine neurotransmitters?
- are constructed from single amino acids and are broken down by monoamine oxidase
What is tyrosine?
is the precursor amino acid of catecholamines
what is tryptophan?
is the precursor amino acid of indoleamines
What is the breakdown enzyme that breaks down Tyrosine into DOPA?
Tyrosine Hydroxylase (TH)
What is the breakdown enzymes that breaks down DOPA into Dopamine?
Dopa Decarboxylase