Med Chem: Cholinergic Neurotransmission

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Definition: Aggregation of nerve cells: Ganglion
Definition: A neuron that originates in the CNS and terminates at the ganglion: Preganglionic
Definition: Neuron from the ganglion to the effector organ: postganglion neuron
What are the two componets of the nervous system?: CNS and PNS
The ________ and ________ make up the CNS: brain and spinal cord
The PNS is made up of the __________ and __________: Efferent (motor) and afferent (sensory)
The afferent (sensory) system goes from ______ to ______: PNS to CNS(senses)
The efferent (motor) system goes from ______ to ______: CNS to PNS
What are the two components of the afferent system?: somatic sensory and visceral sensory
What are the two components of the efferent system?: somatic motor and visceral motor
What are the two divisions of the ANS?: SNS and PSNS
The SNS is responsible for what response?: fight or flight
The PSNS is responsible for what response?: Rest and Digest
The somatic is composed of mostly ____________.: skeletal muscle
The visceral is composed of mostly __________: organs (lungs, heart)
The visceral motor is also known as what nervous system?: Autonomic Nervous System (ANS)
T/F: The PSNS and SNS have opposing effects: True
Identify the division as either PSNS or SNS: Outflow from thoracolumber region of spinal cord: Sympathetic
Identify the division as either PSNS or SNS: Preganglionic neurons are short; postganglionic neurons are long: Sympathetic
Identify the division as either PSNS or SNS: Adrenal gland directly innervated: Sympathetic
Identify the division as either PSNS or SNS: Outflow from cranio-sacral region of the spinal cord: parasympathetic
Identify the division as either PSNS or SNS: Preganglionic neurons are long; postganglionic neurons are short: parasympathetic
Identify the division as either PSNS or SNS: Adrenal medulla, kidney, pilomotor muscle and sweat gland not innervated by neurons: parasympathetic
The SNS flows from what region of the spinal cord?: Thoraco-lumber
In the SNS the preganglionic neurons are ________ and the postganglionic neurons are _____ (long or short): short;long
The PSNS flows from what region of the spinal cord?: cranio-sacral
In the PSNS the preganglionic neurons are _____ and the postganglionic neurons are ________. (long or short): long; short
Definition: Intertwining of preganglionic neurons: Plexus
List two of the four components that are not innervated by parasympathetic neurons.: -Adrenal medulla
-Kidney
-Pilomotor muscle
-Sweat gland
Draw the structure of GABA: *see notes*
GABA: Gamma amino butyric acid
Definition: Endogenous chemical entities that facilitate the transmission of electrical (nerve) impulses: Neurotransmitters
Most neurons are _________ and _______: discreet entities; local
T/F: In general, neurotransmitters are synthesized, stored, released and inactivated locally and the effects are local.: FALSE

NTs are synthesized, stored, released and inactivated LOCALLY but the effects are FAR-REACHING
Are the effects of NT local or far-reaching?: Far-reaching
Apprx. how many types of NTs are known?: ~30
Give an example of a monoamine: -epinephrine
-norepinephrine
-serotonin
Give an example of a peptide (chain of aa linked through peptide bonds): -substance p
-enkephaline
-endorphines
What are some types (categories) of NTs?: -Acetylcholine
-Monoamines
-Amino Acids
-Peptides
What happens after a nerve impulse reaches the synaptic cleft? (outline the process): The nerve impulse reaches the synaptic cleft and releases a NT that binds to a receptor on the post synaptic neuron causing a change in membrane potential
When a receptor is also an ion channel it is known as the ___________ effect.: Ionotropic effect
When a receptor produces a second messenger (ex: cAMP) it is known as the __________ effect.: Metabotropic effect
Neurons that release ACh are termed ___________ neurons.: Cholinergic
Cholinergic neurons release __________.: Acetylcholine (ACh)
Draw the structure for Acetylcholine: *see notes*
ACh is the neurotransmittor of all _____ganglionic fibers of the SNS and PSNS: preganglionic fibers
ACh is the neurotransmittor of all postganglionic fibers of the ___________ division.: parasympathetic division
ACh is the neurotransmittor of all preganglionic and all postganglionic fibers of the ____________ division: parasympathetic
ACh is the neurotransmittor of all preganglionic and few postganglionic fibers of the ____________ division: sympathetic
ACh is the neurotransmittor of what nervous system?: Somatic nervous system
ACh is the neurotransmittor of some neurons of the __________ nervous system.: SOME NEURONS OF THE central nervous system

(vs. entire somatic nervous system)
Where is ACh released?: at the adrenal medulla
What is the role of ACh in the CNS?: cognition, memory, behaviour, coordination of movement
What is the role of ACh in the eyes?: constriction of pupil (miosis)

*accommodates for near vision*
What is the role of ACh in the lungs and bronchioles?: -inc. constriction of bronchioles
-inc. secretion from the tracheobronchial mucosa
What is the role of ACh in the stomach?: increased contraction and secretion
What is the role of ACh in the intestine?: increased motility
What is the role of ACh in the bladder?: contraction (micturition)

**ACh causes the contraction of detrussor muscles of the bladder and causes the relaxation of the sphincter and trigon muscles of bladder (top-constricted; bottom-relaxed)
What is the role of ACh in the heart?: -dec. rate of contraction (negative chronotropic effect)
-dec. force of contraction (negative ionotropic effect)
What is the role of ACh in the blood vessels?: relaxation of smooth muscles of blod vessels (vasodilation)
What is the role of ACh in the exocrine glands?: inc. secretions of salivary, sweat and lacrymal glands
Where do endocrine glands secrete?: directly into the blood/fluid
Cholinergic receptors in the CNS are being investigated for their role in what disease?: Alzheimers disease
A decreased rate of contraction in the heart is known as what effect?: negative chronotropic effect
A decreased force of contraction in the heart is known as what effect?: negative ionotropic effect
What are the two types of cholinergic receptors?: -Nicotinic
-Muscarinic
Nicotinic and Muscarinic are what type of receptors?: Cholinergic
Nicotinic receptors bind _______.: nicotine
Muscarinic receptors bind __________.: muscarine
Both nicotine and muscarine make the compound basic and are known as _____________.: alkaloids
Where is nicotine found?: in tobacco
Where is muscarine found?: in poisionous mushrooms
Muscarine is found in what species of mushroom?: Amanita muscarina
Definition: nitrogen containing compounds; alkaline in nature and found in natural products: alkaloids
Draw the structure of nicotine: *see notes*
Nicotine has a __________ and __________ ring.: pyridine and pyrrolidine ring
T/F: Muscarinic receptors are coupled to ion channels: False; Nicotinic receptors are coupled to ion channels
A completely saturated pyrrole ring is known as what?: a pyrrolidine
Draw the structure of pyrrole: *see notes*
Nicotinic receptors produce an effect in how many milliseconds?: 0.1 to 10 milliseconds
In nicotinic receptors, passage of ions causes the electrical excitability of the ______ and ______ cells.: nerve and muscle cells
In nicotinic receptors, the binding of ACh causes the excitability of the _______ cells.: sensory cells (sent from the periphery to the CNS)
What type of ion channel is a nicotinic receptor?: a ligand-gated ion channel
A nicotinic receptor is a glycoprotein consisting of how many subunits?: Five
Identify the five subunits of the nicotinic receptor: 2 alpha, beta, gamma, delta
What is a glycoprotein made of?: a protein and a carbohydrate
ACh binds to the _______ subunit of the nicotinic receptor: alpha
Is the Ionotropic or Metabotropic effect faster?: Ionotropic (b/c the receptor is also an ion channel); The metabotropic effect has a lagtime due to the downstream process
Where are the NTs released?: at the synapse
Where is the nicotinic receptor located?: at the neuromuscluar junction
Definition: Contraction of skeletal muscle; where the nerve innervates the muscle: Neuromuscular Junction
What type of disease is Myasthenia gravis?: autoimmune disease
List two symptoms of Myasthenia gravis: -muscle weakness
-drooping eyelids
-lethargy
-possible paralysis
Muscle weakness, lethargy, drooping eyelids and possible paralysis are symptoms of what autoimmune disease?: myasthenia gravis
Where is the target location of muscle relaxants?: NMJ
A blockade of the autonomic ganglia can cause severe hypertention or hypotention?: hypotention
A blockade of the ___________ can cause severe hypotention: autonomic ganglia
T/F: The role of the nicotinic receptor is not completely understood in the CNS: True
In an autoimmune disease the nicotinic receptors are destroyed by the _____________ of the body.: antibodies
T/F: The autonomic ganglia causes a blockate that blocks the effect of ACh at the NMJ.: True
What three drugs block N1 receptors?: -decamenthonium
-d-tubocurarine
-succinyl chloride
Where are N1 receptors located?: NMJ
Where are N2 receptors located?: Autonomic ganglia
N2 receptors are blocked by ________________.: hexamethonium
Does Hexamethonium block N1 or N2 receptors?: N2 receptors
Does Decamenthonium block N1 or N2 receptors?: N1 receptor
Does D-tubocurarine blocks N1 or N2 receptors?: N1 receptors
Does succinyl chloride block N1 or N2 receptors?: N1 receptors
*List some nicotinic receptor subtypes?: Decamethonium
Succinylcholine
Hexamethonium
Draw the structure of furan: *see notes*
Definition: Basic structure found in compound that classifies it as a certain drug: pharmacophore
Definition: A fully saturated furan ring?: Tethra hydro furan (THF)
What type of ring does muscarine have?: a tetrahydrofuran ring
_____________ receptors mediate most of ACh responses. (nicotinic or muscarinic): muscarinic
ACh on muscarinic receptors stimulates secretion of _________ and ________ glands.: salivary and sweat glands
ACh on muscarinic receptors stimulates _____________ and ____________ of the gut.: secretions and contraction
ACh on muscarinic receptors _____________ airways of respiratory tract. (constricts/dialiates): constricts
ACh on muscarinic receptors _____________ contraction of heart. (increases/decreases): decreases
ACh on muscarinic receptors ___________ smooth muscles of blood vessels. (contracts/relaxes): relaxes (causes vasodialation)
ACh on muscarinic receptors _____________ secretions and contraction of the gut. (stimulates/inhibits): stimulates
ACh on muscarinic receptors ____________ secretion of salivary and sweat glands. (stimulates/inhibits): stimulates
Muscarinic Receptors are present in what two nervous systems?: CNS and PNS
How many transmembrane helical proteins make up the muscarinic receptor?: SEVEN transmembrane helical protein domain
What are the three structural domains of a muscarinic receptor.: -seven transmembrane helical protein domain
-intracellular domain
-extracellular domain
Muscarinic receptors are __-protein coupled receptors.: G-protein
Are G-protein coupled receptors muscarinic or nicotinic?: muscarinic
Definition: A family of proteins that binds to the guanine nucleotides (GTP, GDP, etc): G-proteins
Is the transmission of impulse faster in nicotinic or muscarinic receptors?: nicotinic
Why is the transmission of impulse in muscarinic receptors is slower than nicotinic receptors?: the second messenger cascade
Apprx. what is the transmission of impulse in muscarinic receptors (in msec)?: ~100 msec
What are the two componets of the muscarinic second messenger cascade?: -adenylate cyclase system
-phosphoinositol system
Where is the storage site for calcium?: Endoplasmic Reticulum
How many muscarinic receptor subtypes are there?: Five subtypes (M1 through M5)
Where is the M1 subtype located?: mostly in the CNS, also in GIT
Where is the M2 subtype located?: mostly in the heart
Where is the M3 subtype located?: exocrine glands and smooth muscle
Where is the M4 subtype located?: tracheal smooth muscle
Where is the M5 subtype located?: tissue location is still under investigation
EDRF: Endothelium derived relaxing factor
What subtype is located mostly in the CNS and also in the GIT?: M1
What subtype is found mostly in the heart?: M2
What muscarinic subtype is found in the exocrine glands and smooth muscle?: M3
What muscarinic subtype is found in the tracheal smooth muscle?: M4
Which muscarinic receptor is thought to be involved in Alzheimers Disease?: M1
What three muscarinic receptors cause stimulaton of PLC: M1, M3 and M5
What two muscarinic receptor subtypes cause inhibition of adenylate cyclase?: M2 and M4
M2 and M4 cause inhibition of ____________.: adenylate cyclase
M1, M3 and M5 cause stimulation of __________: PLC (coupled to Gs protein)
What is another name for Endothelium derived relaxing factor (EDRF)?: Nitric Oxide
What is the function of EDRF or nitric oxide?: it is a potent vasodialator
What are the two main types of G proteins?: Gq (stimulatory)
Gi (inhibitory)
What is the name of the main stimulatory G protein?: Gq
What is the name of the main inhibitory G protein?: Gi

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