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T.R. elliot and chemical transmission at synapse
applied adrenaline on various organs and it created the same reaction as sympa NS
Otto Loewi - Chemical Synaptic Transmission
Showed chemical transmission in nervous system 1. Stimulated the vagus nerve in frog, and observed heart slowed down. (Bradycardia) 2. ACh from vagus slowed down frog heart.  3. Perfused the heart and took substance in the perfused heart and administered fluid sample onto naive heart. …
What was Loewi's evidence that neurotransmission depends on the release of chemicals?
When Loewi stimulated a nerve that increased or decreased a frog's heart rate, he could withdraw some fluid from the area around the heart, transfer it to another frog's heart, and thereby increase or decrease its rate also. He was collecting and transferring chemicals.
Name the sequence of chemical events in synapse:
1).The neuron synthesizes the chemicals that serve as neurotransmitters (neurotransmitters in axon terminals and neuropeptides in the cell body). 2). Action potentials travel down the axon.At the presynaptic terminal, an action enables calcium to enter the cell, which then releases the n…
Name/describe 6 main categories of neurotransmitters:
amino acids-acids containing amine group (NH2) monoamines-chemicals formed by a change in certain amino acids acetylcholine- (a one member "family") a chemical similar to an amino acid, except that it includes an N(CH3)3 group instead of (NH2) neuropeptides- chains of amino acids puri…
Name the neurotransmitters within the 6 main categories:
1). Amino acids- glutamate, GABA, glycine, asparate, maybe others 2). A modified amino acid- acetlycholine 3). Monoamines- indoleamines, serotonin, catecholamines, dopamine, norepinephrine, epinephrine 4). Neuropeptides- endorphins, substance P, neuropeptide Y, maybe others 5). Purine…
What is nitric oxide (NO) and what is its function?
a gas released by many small local neurons (poisonous in large quantities and difficult to produce in lab, yet neurons contain an enzyme to make it efficiently). Function: when neurons are stimulated, many of them release nitric oxide which, in addition to influencing other neurons, dilat…
Neurons synthesize nearly all neurotransmitters from _______ ______, which the body obtains from ______ in the diet. 
amino acids, proteins 
Catecholine
- contain a catechol group and an amine group -only excitatory -norepinephrine, epinephrine, & dopamine
What is trpytophan and how can you increase the entry into your brain?
-precursor to serotonin, crosses the BBB by special transport that it shares with other large amino acids. It still has to compete to cross. -you can increase entry to the brain when consuming carbohydrates -Why? Carbs increase release of insulin, which takes several competing amino aci…
When are neurotransmitters synthesized  What's an exception?
they are usually synthesized in the presynaptic terminal, near the point of release. An exception to this rule is nitric oxide: neurons release it as soon as they form it instead of storing it). Vesicles tiny nearly spherical packets that are used by the presynaptic terminal to store hi…
Is it possible for a neuron to accumulate excess levels of a neurotransmitter  If so, whats a possible solution?
Yes. MAO (monoamine oxidase) is an enzyme, released by serotonin, dopamine, and norepinephrine, that breaks down these transmitters into inactive chemicals. (used in antidepressants).
True or False: Action potential is what causes the release of neurotransmitters. Explain. 
False. The depolarization opens voltage-dependent calcium gates in the presynaptic terminal. Within 1-2 ms after calcium enters those gates, it causes exocytosis. - (even if an action potential does try to release any neurotransmitters, which it often fails, the amount varies)
Exocytosis
release of neurotransmitters in bursts from the presynaptic terminal to the synaptic cleft. 
How fast does a neurotransmitter diffuse across the synaptic cleft? How wide are clefts? 
- takes no more than .01 ms to diffuse across a 20-30 nanometer (nm) wide cleft.
Why does a neuron release a combination of transmitter instead of just one?
Presumably the combination makes the neuron's message more complex. 
Can neurons receive and respond to transmitters that they don't release?
Yes, because varies locations on a membrane of that neuron might have receptors for varies transmitters.  
When the action potential reaches the presynaptic terminal, which ion must enter the presynaptic terminal to evoke release to the neurotransmitter?
Calcium
How does the effect of the neurotransmitters depend on the receptors on the postsynaptic cell?
When the neurotransmitter attaches to its receptor, the receptor may breifly and quickly open the channel - exerting an ionotropic effect, or it may produce a slower but longer effect - a metabotropic effect. 
Explain an ionotropic receptor:
Since these channels are transmitter-gated or ligand-gated, the channel opens once the neurotransmitter binds to a receptor , which is shaped to let a particular type of ion pass. 
Explain ionotropic effects: How fast does it begin? When do the effects decay? What actions is it well suited for conveying? 
the effects begin sometimes within less than a millisecond after the transmitter attaches. The effects decay with a half-life of about 5 ms. They are well suited in conveying visual info, auditory info, and anything else needed to be updated as quickly as possible. 
Most of the brain's excitatory ionotrpoic synapses use the neurotransmitter _______.
glutamate, the most abundant neurotransmitter in the nervous system. (can also use acetylcholine)
Most of the inhibitory ionotrpoic synapses use the neurotransmitter ______ and _____. 
-GABA (gamma-amino-butyric-acid), causes chloride gates to open which enables chloride ions, with their negative charge, to cross them membrane into the cell more rapidly than usual. -Glycine
When an ionotropic receptor is at rest what happens?
the inner channel coils together preventing the inner flow of sodium. 
Explain metabotropic effects: How fast does it begin? When do the effects decay? What actions is it well suited for conveying?
these effects initiate a sequence of metabolic reactions that are slower and longer lasting than iontopic effects. -the effects emerge 30 ms or more after the release of the neurotransmitter is released - the last up to a few seconds, sometimes longer well suited for more enduring effe…
Most of the metabotropic synapses use the multiple neurotransmitters, such as:
- dopamine, norepinphrine, serotonin, and sometimes even glutamine and GABA, too.
What happens when a neurotransmitter binds to a metabotropic transmitter?
it bends the recepetor protein that goes through the membrane of the cell which then detaches the G-protein, which is then free to take its energy elsewhere in the cell. 
G protein
a protein coupled to guanosine triphosphate (GTP), an energy storing molecule. 
What are the second messengers, and which type of synapses relies on them?
At metabotropic 
Just as the the neurotransmitter carries information to the postsynaptic cell, the ___________ communicates to many areas within the cell.
second messenger
How does ondansetron work?
serotonin antagonist (blocks receptors); central-acting antiemetic (Think: You will not vomit with ondansetron, so you can go On DANCing). Commonly used with cancer patients undergoing treatment. 
Explain neuropeptides, how they spread, how long they last, and what functions are they important for?
-(or neuromodulators) are synthesized in the cell body and released mainly by dendrites, cell body, or axons. -Their release requires repeated stimulation but are released in substantial amounts (because once it is released it primes other dendrites to release). -their effects can last …
True or False: Neuropeptides are like neurotransmitters in the sense they are released immediately adjacent to their receptors. Explain.
False, neuropeptides diffuse widely, affecting many neurons in their region of the brain. 
What is an exception to the idea that neurotransmitters only are released in small areas adjacent to their receptors?
A neurogliaform cell is a neuron that is shaped more like a glia cell and releases huge amounts of GABA all at once, forming a cloud that spreads to a large number of neurons in the area, producing widespread inhibition. 
Compare instinctive features of neuropeptides and other neurotransmitters: 1)Place synthesized: 2)Place released: 3)Released by: 4)Effect on neighboring cells: 5)Spread of effects: 6)Duration of effects:
1)cell body VS presynpatic terminal 2)dendrites, axon, cell body VS axon terminal 3)repeated depolarization VS single action potentials 4)release neuropeptides to others VS no effect on neighbors 5)diffuse to wide area VS mostly effect receptors of the adjacent postsynaptic cell 6)Ma…
Hormone
one of the many types of secreted chemicals that are formed in specialized cells, travel in body fluids, and act on specific target cells in other parts of the body to change their functioning
Endocrine Glands
ductless glands that secrete hormones
Hormones are particularity useful in coordinating ______ changes in multiple parts of the body. 
long-lasting
peptide hormones and protein hormones
chains of amino acids; peptide hormones are short chains and protein hormones are long chains. 
What do protein and peptide hormones do?
attach to membrane receptors, where they activate a second messenger within the cell, exactly like a metabotropic synapse. 
True or False: Many chemicals serve as both neurotransmitters and hormones. Explain.
True, (relate back to second messenger and metabotropic effects). -norepinphrine and dopamine
anterior pituitary
composed of glandular tissue, synthesizes six hormones, but the hypothalamus controls their release
releasing hormones
hormones produced by the hypothalamus that act on the anterior pituitary(by flowing through blood) to release tropic hormones
Name the following hormones described: 1)controls the secretions of the adrenal cortex 2)controls secretions of the thyroid gland 3)controls secretions of the mammary glands 4)promotes growth throughout the body 5)controls secretions of the gonads
1) Adrenocorticotropic hormone (ACTH) 2) Thyroid-stimulating hormone (TSH) 3) Prolactin 4) Somatotropin (growth hormone, GH) 5) Gonadotropins, follicle-stimulating hormone (FSH) and Luteinizing hormone (LH)
H.1.4 Outline the relationship between the hypothalamus and the pituitary gland. Posterior Pituitary Lobe
1. Neurosecretory cells connect the hypothalamus and the posterior pituitary lobe; 2. Hormones secreted from the posterior lobe are produced in the hypothalamus; 3. Nerve impulses travel down the axon into the posterior pituitary;  4. This causes the release of the vesicles of hormones…
Which part of the pituitary-anterior or posterior- is neural tissue, similar to the hypothalamas? Which part is the glandular tissues and produces hormones that control the secretions by other endocrine organs?
POSTERIOR, ANTERIOR 
In what way is a neuropeptide intermediate between other neurotransmitters and hormones? 
Most neurotransmitters are released in small amounts close to their receptors. Neuropeptides are released into a brain area in larger amounts or not at all. When they're released, they diffuse more widely. Hormones are released into the blood for diffuse delivery throughout the body.
acetyhlcholinesterase 
enzyme that breaks up acetylcholine into the two fragments of: acetate and choline. The choline then diffuses back into the presynaptic neuron and is basically recycled. This takes time.
True or False: Serotonin and the catecholamines (dopamine, norepinephrine and epinephrine) break down into inactive fragments at the postsyanptic membrane. Explain.
False, they simply detach from the receptor.
reuptake
neurotransmitter are taken back into the synaptic vesicles (so area is clear for next firing). 
transporters 
special membrane proteins used in reuptake. 
COMT (catechol-o-methyltransferase) 
Occurs when dopamine accumulates, breaks down the excess dopamine into inactive chemicals that cannot stimulate more receptors, diminishes the supply of dopamine for the neurons. Used when there are fewer transporters present and reuptake is slow. 
True or False: Neuropeptides are neither inactivated nor reabsorbed. Explain.
True, they simply diffuse away. Because these large molecules are resynthesized slowly, a neuron can temporarily exhaust its supply. 
autorecepters
-the signal to stop the release of neurotransmitters when there is an excess of neurotransmitters -traffic control
Other than autoreceptors, what else is an example of negative feedback from the postsynapitc cell?
some postsynpatic neurons respond to stimulation by releasing special chemicals that travel back into the presynaptic terminal, where they inhibit further release of the transmitter. Some include: nitric oxide, 2-AG, and anandamide. 
explain gap junction: 
at an electrical synapse, the membrane of one neuron comes into direct contact with the member of another. These pores are large enough for sodium and other ions to pass readily, and unlike the other member channels we have considered. THESE PORES REMAIN OPEN CONSTANTLY. EX: whenever one …

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