CNS Neurotransmitters Flashcards
Divide up by molecular structure for neurotransmitter
What are the categories of neurotransmitter
Amino acid neurotransmitter - amino group and carboxylic acid group
Peptide neurotransmitters - polymers or chains of amino acids
Monoamine neurotransmitters / biogenic amines - organic molecules with amino groups corrected to aeromatic group - these are connected by 2 carbon chain some are also called catecholamines (subgroup) these have a catcehol group as have benzene ring and hydroxyl group
Many other types of neurotransmitters
Examples of aa neurotransmitters
Glutamate , Gamma anime neutering acid GABA , and glycine
Glutamate
Most exciting causing depolarisation
Most common inhibitory neurtanimitor causing hyperpolarisiton
GABA - in brain inhibitory
Glycine - in the spinal cord inhibitory
Example of monoamines
Serotonin Histamine Dopamine Epinephrine Norepinephrine
3 catecholamines
Dopamine
Epjnephiner and norepinephrine
What do monoamines do
Control attention , cognition and emotion
Many autoimmune conditions arise from these
NA - autonomic
Example of peptides
Opioid - endorphin - perception of pain
Pain medications affect these
Other neurotransmitters
Acetylcholine - function in both CNS and peripheral in ANS and released by motor neurones that synapse on skeletal muscles
criteria for accepting a substance as atransmitter
- synthesized in the neuron,
- released in sufficient quantity to elicit a response
- Mechanisms for removal or inactivation of the neurotransmitter from the synaptic cleft must exist
- It should mimic the action of the endogenously released neurotransmitter when administered exogenously at or near a synapse.
examples of excitatory aa neurotransmitters
glutamate and aspartate
examples of inhibitory aa neurotransmitters
GABA and glycine
example of biogenic amines neurotransmitters
catecholamines - the 3
indoleamines - serotonin
imidazole amines - histamine
example of purines
ATP
adenosine
opioid peptides are neuropeptides examples
b-endorphin
example of a gaseous neurotransmitter
NO
small molecule neurotransmitter start are RER then synthetic enzymes to golgi and axonal transport to neurotransmitter along with precursor formed from last neurotransmitter enters vesicle and exocytosis and calcium influx
what happens for neuropeptides
RER- propertied and enzymes containing vesicles - golgi - axonal transport via microtubules - cleavage and propeptide to smaller peptide neurotransmitter and excytosis
neurotransmitters receptors are either what
ionotrophic - ligand - charged ions either positively or negatively charged move in or out of cell
metabotrophic - G protein coupled
these activate other itnraceullar signalling cascades
activate ion channels
glutamate is an excitatory transmitter and uses both receptors ( NMDA, AMPA and mGluRs) how is it cleared and what is its physiological effect
memory formation
glutamate synthesis reuptake and diffusion
via glial cells
serotonin is either excitatory or inhibitory and uses GPCR what receptor, what physiological effect and clearance
5-HT
mood regulaiton
reuptake in pre synaptic by SERT and diffusion
GABA is an inhibitory neurotransmitter except in early development. is receptors are GABAa ( ionotrophic) and GABAb ( metabotrophic ) what physiological effect and clearance
decreased CNS activity
glutamien synthase reuptake
ACH uses nicotinic and muscarinic receptors and is predominantly excitatory what is its physiological role and clearance
memory formation
ACHE breakdown - choline and acetate , choline and sodium transporter goes back in
glial cell takes the acetate
dopamine has receptors D1-5 and GPCRs it is excitatory and inhibitory depending on receptor and brain location what is its clearance and physiological effect
reward pathways, motivation
liver into MAO/COMT catalyse breakdown of catecholamines
MAO/COMT reuptake and diffusion
case 1 - your brother has been suffering from epileptic seizures. Neurologist has suggested his brain is overexcited and he has been prescribed th anticonvulsant sodium valproate. Explain how a brain can be excited and how sodium valproate stops this
reduces neuronal excitability by inhibiting voltage gated sodium channels but also by increasing availability of the inhibitory neurotransmitter GABA
case 2 - nicotine can help prevent alzeihemers. neighbours mum said galantine. described the differences and commonalities of the action of nicotine versus galantine in the brain
Galantine is an acetylcholinesterase inhibitor it therefore prevents the breakdown of acetylcholine, meaning that acetylcholine is present for longer in the synaptic cleft
Nicotine is a direct agonist of nicotinic acetylcholine receptors, and therefore activates these synaptic receptors. It therefore does not require presynaptic activity to exert an effect on synaptic transmission
case 3 - housemate says feeling low for long time and sleep disturbances. which commonly prescribed drug might help to alleviate these symptoms and explain how they work in brain
MAOIs-prevent the breakdown of monoamine neurotransmitters such as dopamine and serotonin, thus increasing their availability
SSRIs-prevent the clearance of serotonin from the synaptic cleft by reuptake
Both dopamine and serotonin are implicated in reward signalling and moo
Activation of which of the following receptors by glutamate causes immediate activation of the post-synaptic neurone?
AMPA receptors mediate fast excitatory neurotransmission in the CNS via glutamate- sodium and potassium channel
NMDA is voltage calcium
Glutamate is also used in the synthesis of the inhibitory neurotransmitter GABA. The enzyme glutamate decarboxylase (GAD) is responsible for this conversion step. Loss of GAD can result in
stiff person syndrome.
what is stiff person syndrome
Neurological disorder involving auto-antibodies against GAD
Loss of GAD results in lower levels of the GABA
symptoms of stiff person syndrome and what do patients normally develop
Symptoms and signs include muscle stiffness and spasms
Patients may also develop diabetes mellitus due to GAD being present in the pancreas
drug induced lupus presents with what autoantibodies
anti-histone antibodies
