Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
22 Cards in this Set
- Front
- Back
|
Synaptic vesicles need to be properly positioned in the presynaptic terminal so that NT can be released within millisecond of the action potential reaching the terminal. Vesicles that are ready to be released are "docked" at the presynaptic membrane-What is the molecular basis for this docking?
|
Process of docking:
1. Vesicle SNARE on the vesicle recognizes and binds to target SNARE 2. The helices of vSNARE, tSNARE, and SNAP entwine to bring the vesicle into close contact with the presynaptic membrane 3. The process will pause, leaving the vesicles 'docked' |
|
|
How does Calcium influx affect the docking process and lead to membrane fusion and transmitter release?
|
Calcium influx is required for the complete zipping up of the helices
-Once zipped the membranes become closely associated and fuse allowing release of the neurotransmitter |
|
|
Synaptic vesicles that are held farther back in the presynaptic terminal are localized there by what molecular mechanism?
|
The vesicles are held in reserve by being tethered to the actin cytoskeleton by synapsis.
|
|
|
How does Calcium influx effect the arrangement of the synaptic vesicles?
|
Calcium influx activates CaM-Kinase II which will phosphoryltae the synapsins.
-causes conformation change of the synapsin -allows for the release of the vesicles |
|
|
What is the purpose of the blood brain barrier?
|
The blood brain barrier helps regulate the environment of the CNS and protects the brain from damaging compounds in the blood.
|
|
|
Name four specializations of brain enodthelial cells that contribute to the blood brain barrier.
|
Specialization of the cells of the Blood Brain Barrier:
1. Tight Junctions 2. Limited pincytosis and transcytosis 3. Extensive enzyme systems to metabolize drugs 4. high expression of ABC transporters to pump drugs back into the blood |
|
|
How do the basement membrane and astrocytes contribute to the barrier?
|
The basement membrane surrounds the blood vessels.
Astrocytes end-feet surround the basement membrane |
|
|
Why is the blood brain barrier a concern in medical practice?
|
The BBB is is a concern in medicine because the drugs that are being prescribed to treat issues within the CNS must be able to cross the blood brain barrier.
|
|
|
The initial steps of catecholamine synthesis and serotonin synthesis are very similar. Which amino acids are each of these neurotransmitters synthesized from and how are the first two steps of synthesis similar?
|
1. Catecholamines are made from TYROSINE
2. Serotonin is made of TRYPTOPHAN 3. The first two steps are similar: -Step one takes AA to an intermediate via TYROSINE hydroxylase ---> binds to BH4 and converts it to BH2 -Step two takes the intermediate to the final product (SEROTONIN OR DOPAMINE) via dopa decarboxylase ---> Interacts with pyridoxal (PLP) phosphate (PLP) and releases CO2 |
|
|
How are CATECHOLAMINES and SEROTONINS receptors similar?
|
Catecholamines & Serotonin have G-coupled receptors
|
|
|
Understand how MAO Inhibitors, SSRIs, SNRIs, and tricyclic antidepressants each work?
|
MAO inhibitors: MonoAmine Oxidase Inhibitors
SSRIs: Selective Serotonin Reuptake Inhibitiors SNRIs: Serotonin-Norepineprine Reuptake Inhibitors --Trycyclic antidepressants are SNRIs. They can be 5-HT receptor antagonists. |
|
|
GABA and Glycine are both inhibitory amino acid neurotransmitters. How are their receptors similar?
|
GABA and Glycine's receptors are:
1. Ligand-gated chloride channels 2. Belong to the "cys-loop" family of ligand-gated ion channels ----Made of 5 subuntis |
|
|
How do GABA and Glycine's anatomical distribution differ?
|
Glycine is the Major INHIBITOR in the brainstem and the spinal cord
GABA is the major inhibitor in the BRAIN |
|
|
Glutamate can be synthesized from which TCA cycle intermediate?
|
Glutamate can be synthesized by GLUCOSE.
---> ALPHA-KETOGLUTERATE from the TCA cycle is converted to glutamate via glutamate dehydrogenase |
|
|
Glutamate can also be synthesized from which amino acid?
|
Glutamate can be synthesized from teh amino acid Glutamine by glutaminase
|
|
|
How is GABA synthesized?
|
GABA is made from glutamate by glutamic acid decarboxylase
|
|
|
If astrocytes uptake glutamate from teh synapse, which chemical do they convert it to for transport back into neurons?
|
Cleared glutamate is converted to glutamine then sent back to the neurons.
|
|
|
Acetylcholine is crucial for what two aspects of peripheral nervous system function?
|
Ach is crucial for the Neuromuscular junction and Automonic Nervous System.
--Parasympathetic: Pre & Post Ganglionic Parasympathetic Neurons ---Sympathetic: Preganglionic sympathetic neurons |
|
|
How is acetylcholine cleared from the synapse?
|
Ach is cleared from the synapse by degradation done by acetylcholinesterase.
|
|
|
Symptoms & Molecular Causes of Multiple Sclerosis.
|
Autoimmune Disease
1. Symptoms: slow synapse, seen in muscles typically 2. Causes: antibodies against components of myelin |
|
|
Symptoms and Molecular causes of Myasthenia Gravis.
|
Autoimmune Disease
-Symptoms: muscle weakness -Cause: antibodies against nicotinic Ach receptor at the NMJ |
|
|
Symptoms of Lambert-Eaton Myasthenic Syndorome
|
Autoimmune Disease
-Symptom: muscle weakness -Cause: antibodies are against P-type voltage gated calcium channels --> the calcium channels are involvled in Ach release at the NMJ |
