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SP 6-RG: Synapses and Neurotransmitters
SP 6-RG: Synapses and Neurotransmitters Notecards
274
Physiology
Undergraduate 3
11/14/2012

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Term
The __________ is the point where the neuron meets a target cell.
Definition
1) Synapse
Term
The two types of synpases are __________ and __________.
Definition
1) Electrical
2) Chemical
Term
What are the three components of a chemical synapse?
Definition
1) Presynaptic cell
2) Synaptic cleft
3) Postsynaptic cell
Term
__________-__________ are junctions that mediate information transfer from one neuron to another.
Definition
1) Neuro-synapse
Term
A __________ __________ is a junction that mediates information transfer from one neuron to an effector cell (when a muscle is involved)
Definition
1) Neuromuscular synapse
Term
A __________ __________ is a junction that mediates information transfer from one neuron to an effector cell (when a gland is involved)
Definition
1) Neuroglandular synapse
Term
What are the two major types of synapses?
Definition
1) Electrical
2) Chemical
Term
The fiber's bouton is called the __________ __________ and the structure it contacts is the __________ __________.
Definition
1) Presynaptic element
2) Postsynaptic element
Term
An __________ __________ is a low resistance pathway between cells that allow current to flow directly from one cell to another.
Definition
1) Electrical synapse
Term
In invertebrates and mammals, electrical synapses occur between __________ __________ and __________.
Definition
1) Glial cells
2) Neurons
Term
The __________ __________ is the morphological correlate of an electrical synapse.
Definition
1) Gap junction
Term
Electrical sypnases are __________ (no delay) and __________ (can flow across the gap junction).
Definition
1) Fast
2) Bidirectional
Term
Studies of __________ and __________ neurons offered the first compelling evidence for electrical synapses.
Definition
1) Crayfish
2) Shrimp
Term
Pre and postsynaptic neurons are joined by __________ __________; this allows local __________ to flow between adjacent cells.
Definition
1) Gap junctions
2) Current
Term
Electrical synapses can be found in both the __________ and __________.
Definition
1) CNS
2) PNS
Term
Electrical synapses are found in __________ and __________ muscle.
Definition
1) Cardiac
2) Smooth
Term
Electrical synapses are important where __________ activity among a group of cells are a major function.
Definition
1) Contractile
Term
Electrical synapses were revealed in the vertebrate CNS of __________ fish soon after.
Definition
1) Teleost
Term
__________ are proteins and __________ are tubes in the cell membrane.
Definition
1) Protein
2) Tubes in the cell membrane
Term
In the most commonly used nomenclature, connexins are named for their predicted __________ __________.
Definition
1) Molecular weights
Term
Each gap junction hemichannel, also known as a connexon, is a __________ __________.
Definition
1) Connexin hexamer
Term
Approximately __________ of the mammalian connexins are abundant in the __________.
Definition
1) Half
2) CNS
Term
__________ may not be the only channel-forming proteins in the electrical synapses of the mammalian brain.
Definition
1) Connexins
Term
__________ __________ in mammalian brains proved much harder to find.
Single-cell recordings provided the first strong evidence for mammalian electrical synapses in the __________ nucleus of cranial nerve __________, the __________ nucleus, and the __________ __________ nucleus.
Definition
1) Electrical synapses
2) Mesencephalic
3) V
4) Vestibular
5) Inferior olivary
Term
On the bases of the distribution of __________ expression alone, it seems likely that electrical synapses occur in every major region of the __________, although compelling functional and morphological data have been collected for only a few years.
Definition
1) Cx36
2) CNS
Term
The pre and postsynpatic elements are separated by a space 15-200nm wide known as the __________ __________.
At the synapse, the membrane of the __________ element is slightly thickened, and there is often an accumulation of some electron dense material near the thickened membrane.
Definition
1) Synaptic cleft
2) Postsynaptic
Term
__________ synapses make up the majority of synapses.
Definition
1) Chemical
Term
__________ synapses use neurotransmitter to carry information from cell to cell.
Definition
1) Chemical
Term
Axon terminals have __________ and __________ __________ containing neurotransmitters.
Definition
1) Mitochondria
2) Synaptic vessels
Term
What are the five steps for the release of neurotransmitters?
Definition
1) Action potential reaches axon terminal of presynaptic neuron
2) Ca2+ enter synaptic knob (presynaptic axon terminal)
3) Neurotransmitter is released by exocytosis into synaptic cleft
4) Neurotransmitter binds to receptors that are an integral part of chemically gated channels on subsynaptic membrane of postsynaptic neuron
5) Binding of neurotransmitter to receptor opens specific channel
Term
What are the six steps that occur in chemical synapses?
Definition
1) Neurotransmitter stored in vesicles
2) Action potential reaches terminal
3) Depolarization open voltage-gated Ca2+ channels
4) Ca2+ influx triggers exocytosis
5) Vesicles release neurotransmitter into synaptic cleft
6) Neurotransmitter diffuses across synaptic cleft and acts on target cells
Term
The neurotransmitter only fits in __________ receptor.
Definition
1) One
Term
Not all cells have __________.
Definition
1) Receptors
Term
Neurotransmitters are classified as either __________ or __________.
Definition
1) Excitatory
2) Inhibitory
Term
The effect of a neurotransmitter on PSM depends on the type of __________ and not the nature of the neurotransmitter.
Definition
1) Receptor
Term
Some neurotransmitters (__________) attach to the presynaptic terminal in addition to the postsynaptic and then inhibit the release of more __________.
Definition
1) Norepineephrine
2) Neurotransmitter
Term
__________ is a neurotransmitter synthesized in axon terminals.
Definition
1) Acetylcholine (Ach)
Term
Acetylcholine produces a strong excitation of __________ muscle and excites __________ muscle in gut but inhibits the __________.
Definition
1) Skeletal
2) Smooth
3) Heart
Term
Glutamate is a major __________ neurotransmitter in the CNS and is also an __________ __________.
Definition
1) Excitatory
2) Amino acid
Term
GABA is a major __________ neurotransmitter; glycine is also a major inhibitory neurotransmitter responsible for inhibiting __________ of synapses in the __________ __________.
Definition
1) Inhibitory
2) Half
3) Spinal cord
Term
What was the first neurotransmitter identified and the best understood?
Definition
1) Acetylcholine
Term
Acetylcholine is synthesized and enclosed in __________ __________ and is degraded by the enzyme __________ (AChE)
Definition
1) Synaptic vesicles
2) Acetylcholinesterase
Term
Acetylcholine is released by __________ __________.
Definition
1) Cholingeric neurons
Term
What neurons are categorized as cholingeric neurons?
Definition
1) Skeletal muscle motor neurons
2) Parasympathetic and sympathetic preganglionic neurons
3) Parasympathetic postganglionic neurons stimulating smooth muscle, cardiac muscle, and glands
4) Sympathetic postganglionic neurons stimulating sweat glands
Term
Acetylcholine binds to cholinergic receptors also known as __________ or __________ receptors.
Definition
1) Nicortinic
2) Muscarinic
Term
__________ regulate the state of consciousness and mood.
Definition
1) Neuromodulators
Term
What are a few examples of neuromodulators?
Definition
1) Catecholamine
2) Dopamine
3) Norepinephrine
4) Epinephrine
5) Indolamine
6) Serotonin
Term
__________ is a monoamine synthesized from tryosine.
Definition
1) Catecholamine
Term
__________ is a monoamine responsible for motivation.
Definition
1) Dopamine
Term
__________ and __________ are monoamines which respond to stress.
Definition
1) Norepinephrine
2) Epinephrine
Term
__________ is a monoamine synthesized from tryptophan.
Definition
1) Indolamines
Term
__________ is a monoamine found in the midline of the brainstem; it regulates an individual's state of consciousness including sleep, waking, attention, and mood.
Definition
1) Serotonin
Term
What are the three catcholamines?
Definition
1) Dopamine
2) Norepinephrine
3) Epinephrine
Term
Indolamines consist of __________ and __________.
Definition
1) Serotonin
2) Histamine
Term
__________ are a monoamine that is broadly distributed in the brain.
Definition
1) Indolamine
Term
__________ are important sympathetic neurotransmitters.
Definition
1) Catecholamines
Term
__________ play an important role in emotional behaviors and our biological clock.
Definition
1) Indolamines
Term
Enzymes present in the cell determine the length of the __________ __________.
Definition
1) Biosynthetic pathway
Term
__________ and __________ are synthesized in axon terminals.
Definition
1) Norepinephrine
2) Dopamine
Term
Epinephrine is released by the __________ __________.
Definition
1) Adrenal medulla
Term
Norepinephrine is also known as __________.
Definition
1) Noradrenaline
Term
__________ is the main neurotransmitter of the sympathetic branch of the autonomic nervous system.
Definition
1) Norepinephrine
Term
__________ binds to adrenergic receptors
Definition
1) Norepinephrine
Term
Norepinephrine can be __________ or __________ depending on the receptor it is bound to.
Definition
1) Excitatory
2) Inhibitory
Term
Norepeniphrine is important in __________ and __________ - an organisms vigilance.
Definition
1) Attention
2) Arousal
Term
Norepinephrine can also be released by the __________ __________ as a hormone.
Definition
1) Adrenal medulla
Term
Norepinephrine is described as the __________ __________ neurotransmitter.
Definition
1) Feel good
Term
__________ is thought to be involved in the etiology of some bipolar affective disorders.
Definition
1) Norepinephrine
Term
Norepinephrine's removal from synapses can be blocked by __________ and __________.
Definition
1) Antidepressants
2) Cocaine
Term
There are lower levels of norepinephrine in __________ patients and higher levels in the __________ phase of bipolar disorder.
Definition
1) Depressed
2) Manic
Term
The release of norepinephrine is enhanced by __________.
Definition
1) Amphetamines
Term
Dopamine binds to __________ receptors of substantia nigra of the __________ and __________.
Definition
1) Dopaminergic
2) Midbrain
3) Hypothalamus
Term
What are the important physiological functions controlled by dopamine?
Definition
1) Motor control
2) Autonomic functions
3) Regulating hormone release
4) Controlling motivational behavior and reward
Term
What biogenic amine is hypothesized to be at the heart of the mechanisms of all addictive drugs?
Definition
1) Dopamine
Term
Dopamine's release is enhanced by __________ and is blocked by __________.
Definition
1) Amphetamines
2) Cocaine
Term
What neurotransmitter's release is enhanced by amphetamines and blocked by cocaine?
Definition
1) Dopamine
Term
There is a deficient of __________ in Parkinson's disease.
Definition
1) Dopamine
Term
What disease has a deficit of dopamine?
Definition
1) Parkinson's disease
Term
Receptor abnormalities of what neurotransmitter have been linked to the development of schizophrenia?
Definition
1) Dopamine
Term
Receptor abnormalities of dopamine have been linked to the development of __________.
Definition
1) Schizophrenia
Term
Serotonin is synthesized from the amino acid __________.
Definition
1) Tryptophan
Term
Which amino acid is synthesized by the amino acid tryptophan?
Definition
1) Serotonin
Term
Diets high in __________ can elevate serotonin levels.
Definition
1) Tryptophan
Term
Which neurotransmitter may play a role in sleep, appetite, and regulation of moods (aggression)?
Definition
1) Serotonin
Term
Low __________ levels are associated with increased aggressiveness and risk taking.
Definition
1) 5-HT
Term
What are low 5-HT levels associated with?
Definition
1) Increased aggressiveness and risk taking
Term
What neurotransmitter acts in a pathway that monitors carbohydrate intake, acting as a negative regulator of motivation to ingest carbohydrates?
Definition
1) Serotonin
Term
Which neurotransmitter has led to the use of SSRIs as obesity pills?
Definition
1) Serotonin
Term
Drugs that block serotonin's uptake relieve what symptoms?
Definition
1) Anxiety
2) Depression
3) Aggression
Term
Drugs that block the uptake of __________ relieve anxiety, depression, and aggression.
Definition
1) Serotonin
Term
What is an SSRI? What are a few drugs that are classified as SSRIs?
Definition
1) Selective serotonin reuptake inhibitor
2) Prozac
3) Celexa
4) Lexapro
5) Zoloft
Term
Ecstasy targets __________ receptors.
Definition
1) Serotonin
Term
What neurotransmitters are from amino acids and are only found in the CNS?
Definition
1) Glutamate
2) GABA (Gamma aminobutyric acid)
3) Glycine
4) Aspartate
Term
Glutamate has an indirect action via __________ __________ and __________ __________.
Definition
1) G proteins
2) Second messengers
Term
What is the direct action of glutamate?
Definition
1) Opens Ca2+ channels (ionotrophic)
Term
__________ receptors have a high permeability to Ca2+.
Definition
1) NMDA
Term
What is the major excitatory neurotransmitter of the brain?
Definition
1) Glutamate
Term
__________ is important in learning and memory.
Definition
1) Glutamate
Term
Which neurotransmitter is highly toxic to neurons when present for extended periods?
Definition
1) Glutamate
Term
Glutamate is highly toxic to __________ when present for extended periods.
Definition
1) Glutamate
Term
What is an example of stroke neurotransmitter?
Definition
1) Glutamate
Term
Excessive release of glutamate produces __________ in which neurons are literally stimulated to death; the most common cause ischemia due to stroke.
Definition
1) Excitotoxicity
Term
Glutamate aids __________ advance when released by __________.
Definition
1) Tumor
2) Gliomas
Term
What neurotransmitter aids tumor advance when released by gliomas?
Definition
1) Glutamate
Term
__________ is a non-NMDA type ionotropictransmembrane receptor for glutamate.
Definition
1) APMA
Term
What is a non-NMDA type ionotropictransmembrane receptor for glutamate?
Definition
1) APMA
Term
What does NMDA stand for?
Definition
1) N-methyl D-aspartate
Term
What type of neurotransmitter is GABA?
Definition
1) Inhibitory
Term
What is the main inhibitory neurotransmitter in the brain?
Definition
1) GABA
Term
Does GABA have direct or indirect action?
Definition
1) Both (depends on type of receptor)
Term
GABA is selectively permeable to __________ (hyperpolarizes membrane).
Definition
1) Cl-
Term
GABA interneurons throughout the CNS but can be found in the __________ __________ and __________.
Definition
1) Cerebral cortex
2) Cerebellum
Term
Inhibitory effects on GABA are augmented by what?
Definition
1) Alcohol
2) Benzodiazepines
3) Barbituates
Term
What are benzodiazepines?
Definition
1) Antiaxiety drugs like Valium and Librium
Term
What drugs increase the number of GABA receptors and enhance the inhibitory affect of GABA?
Definition
1) Alcohol
2) Benzodiazepines
3) Barbituates
Term
Decreased GABA inhibition may lead to __________.
Definition
1) Epilepsy
Term
Epilepsy may be caused by a decrease of what neurotransmitter's inhibition?
Definition
1) GABA
Term
__________ are large electron dense vesicles.
Definition
1) Neuropeptides
Term
__________ __________ include enkephalins, endorphins, drynorphins, endomorphins, and nociceptin.
Definition
1) Endogenous opiods
Term
__________ was the first chemical shown to bind to opioid receptors.
Definition
1) Morphine
Term
__________ and __________ act as both hormones and transmitters in the brain.
Definition
1) Vasopressin
2) Oxytocin
Term
Neuropeptide receptors are all __________-__________ linked.
Definition
1) G-protein
Term
What does it mean to be G-protein linked?
Definition
1) Levels of intracellular second messengers is altered
Term
__________ __________ occurs in the brain where it is associated with the regulation of mood disorders, anxiety, neurogenesis, neurotoxicity, respiratory rate, nausea, and pain.
Definition
1) Substance P
Term
__________ __________ stimulates appetite and food intake.
Definition
1) Neuropeptide Y
Term
What three opiods attempt to act like regular opiates and reduce our perception of pain?
Definition
1) Beta endorphin
2) Dynorphin
3) Enkephalins
Term
What is found in higher concentrations in marathoners and women who have just given birth?
Definition
1) Opiods, such as beta endorphins, dynorphins, and enkephalins
Term
__________ __________ are not packaged in vesicles and are not released by exocytosis.
Definition
1) Gas neurotransmitters
Term
__________ __________ are highly permanent and simply diffuse from synaptic terminals to neighboring cells.
Definition
1) Gas neurotransmitters
Term
What type of neurotransmitters are not packaged in vesicles or released by exocytosis?
Definition
1) Gas neurotransmitters
Term
What type of neurotransmitters are highly permanent diffuse simply from synaptic terminals to neighboring cells?
Definition
1) Gas neurotransmitters
Term
What are two examples of gas neurotransmitters?
Definition
1) Nitric oxide (NO)
2) Carbon monoxide (MO)
Term
How is nitric oxide synthesized?
Definition
1) On demand vs. constant synthesis
Term
How is nitric oxide released?
Definition
1) Diffuses out of cells vs. being stored in vesicles and released by exoctyosis
Term
What does nitric oxide bind with and how?
Definition
1) Exits the cytoplasm, enters the target cell, and binds with intracellular guanylyl cyclase
Term
Which neurotransmitter is synthesized on demand vs. a constant synthesis?
Definition
1) Nitric oxide
Term
Which neurotransmitter diffuses out of the cells making it vs. being stored in vesicles and released by exocytosis?
Definition
1) Nitric oxide
Term
Which neurotransmitter does not bind to surface receptors, but instead exits the cytoplasm, enters the target cell, and binds with intracellular guanylyl cyclase?
Definition
1) Nitric oxide
Term
Which neurotransmitter binds with guanylyl cyclase?
Definition
1) Nitric oxide
Term
What are the similarities nitric oxide shares in comparison to other neurotransmitters?
Definition
1) Present in presynaptic terminal
2) Natural removal from synaptic junction
Term
__________ __________ is the same substance produced by sublingual nitroglycerin produces to increase vasodilation in relief of angina.
Definition
1) Nitric oxide
Term
__________ __________ is a short-lived gas that diffuses through post-synaptic membranes to bind with intracellular receptors.
Definition
1) Nitric oxide
Term
Which neurotransmitter is a free radical and is therefore a highly reactive compound?
Definition
1) Nitric oxide
Term
__________ __________ is better known as laughing gas.
Definition
1) Nitrous oxide
Term
__________ __________ (along with glutamate) is important in learning and memory.
Definition
1) Nitric oxide
Term
__________ __________ is important in the control of blood flow through cerebrovasculature
Definition
1) Nitric oxide
Term
Some type of male impotence is treated by stimulating __________ __________ release.
Definition
1) Nitric oxide
Term
What are the steps in the release of viagra?
Definition
1) Viagra intake
2) NO releae
3) Smooth muscle relaxation
4) Increased blood flow
5) Erection
Term
__________ __________ cause depolarization whereas __________ __________ cause hyperpolarizations.
Definition
1) Excitatory
2) Inhibitory
Term
Which neurotransmitters cause depolarizations? Hyperpolarizations?
Definition
1) Excitatory
2) Inhibitory
Term
True or False: Some neurotransmitters have both excitatory and inhibitory effects.
Definition
1) True
Term
Explain how acetylcholine has both excitatory and inhibitory effects.
Definition
1) Excitatory at neuromuscular junctions with skeletal muscle
2) Inhibitory in cardiac muscle with heart
Term
What type of amplification do ion channels experience? GPCRs?
Definition
1) Minimal
2) Large
Term
What is the duration for ion channels? For GPCRs?
Definition
1) Fast (10 msec)
2) Long (100 msec-minutes)
Term
True or False: ACh only acts through ionotropic receptors
Definition
1) False: Ach acts through both ionotropic and metabotropic receptors
Term
Amino acids (such as glutamane and GABA) mainly act through what receptors?
Definition
1) Ion channels (ionotropic)
Term
Neuropeptides and biogenic amines mainly act through what receptors?
Definition
1) GPCRs (metabotropic)
Term
What does it mean for something to be ionotropic? Metabotropic?
Definition
1) Ionotropic refers to ion channels
2) Metabotropic refers to G proein-coupled receptors
Term
Which G protein-coupled receptor stimulates adenylate cyclase? Which inhibits?
Definition
1) Gs stimulates
2) Gi inhibits
Term
What are five examples of GPCR second messengers?
Definition
1) cAMP
2) cGMP
3) DAG
4) IP3
5) Ca2+
Term
What is the role of the majority of second messengers?
Definition
1) Stimulate protein phosphorylation and dephosphorylation
2) Affect cell metabolism, gene expression, and ion channels
Term
GPCRs have a diverse and complex modulatory influences on __________ and __________ states.
Definition
1) Physiological
2) Behavioral
Term
What type of receptors are nicotinic receptors?
Definition
1) Ion channels (iotonic)
Term
Where can nicotinic receptors be found?
Definition
1) On sacrolemma of skeletal muscle fibers
2) On dendrites and cell bodies of all postganglionic neurons of the ANS
Term
Nicotinic receptors are on the __________ of skeletal muscle fibers and the dendrites and cell bodies of all __________ neurons in the __________.
Definition
1) Sacrolemma
2) Postganglionic
3) ANS
Term
Are nicotinic receptors excitatory or inhibitory?
Definition
1) Excitatory (open Na+ channels to a fast EPSP)
Term
__________ __________ are G-protein couple receptors found on all parasympathetic target organs.
Definition
1) Muscarinic receptors
Term
Where can muscarinic receptors be found?
Definition
1) On all parasympathetic target organs (cardiac and smooth muscle)
Term
True or False: Muscarinic recptors can only be inhibitory
Definition
1) False: Muscarinic receptors can be excitatory or inhibitory
Term
In nicotonic Ach receptors, the __________ __________ synapses with __________ muscle.
Definition
1) Motor neuron
2) Skeletal
Term
Nicotine mimics the effect of what neurotransmitter?
Definition
1) Ach
Term
__________ mimics the effect of Ach?
Definition
1) Nicotine
Term
__________ blocks the effect of Ach and causes paralysis.
Definition
1) Curare
Term
What are the two types of muscarinic receptors and what are they responsible for?
Definition
1) M1: Intestine; closes K channels to depolarize
2) M2: Heart; opens K channels to hyperpolarize
Term
What occurs when the effects of acetlycholine are prolonged?
Definition
1) Muscle spasms
2) Neural frying
Term
Effects of acetylcholine can be prolonged by __________ __________ and __________ __________ (malathion).
Definition
1) Nerve gas
2) Organophosphate insecticides
Term
Ach receptors are destroyed by the patients own antibodies in __________ __________.
Definition
1) Myasthenia gravis
Term
What disease destroys acetylcholine receptors?
Definition
1) Myasthenia gravis
Term
Binding to acetylcholine receptors is inhibited by __________.
Definition
1) Curare
Term
What muscle paralytic agent is responsible for inhibiting binding to acetlycholine?
Definition
1) Curare
Term
What is curare?
Definition
1) A muscle paralytic agent
Term
__________ receptors belong to the large super family of seven transmembrane-spanning G protein-coupled receptors
Definition
1) Opioid
Term
Opioid receptors are activated both by endogenously produced __________ __________ and by exogenously administered __________ __________, some of which are not only among the most effective __________ known but also the most highly addictive drugs of abuse.
Definition
1) Opioid peptides
2) Opiate compounds
3) Analgesics
Term
__________ and __________ are commonly used opioid antagonist drugs which are competitive antagonists that bind to the opioid receptors with higher affinity than antagonists but do not activate the receptors. This effectively blocks the receptors, preventing the body from responding to opiates and endorphins.
Definition
1) Naloxene
2) Naltrexone
Term
What are the two most commonly used opioid antagonist drugs?
Definition
1) Naloxene
2) Naltrexone
Term
What are the three steps in the inactivation of neurotransmitters?
Definition
1) Neurotransmitters can be returned to axon terminals for reuse or transported into glial cells
2) Enzymes inactivate neurotransmitters
3) Neurotransmitters can diffuse out of the synaptic cleft
Term
The removal of a neurotransmitter from the synaptic cleft largely depends on the __________.
Definition
1) Neurotransmitter
Term
In the removal of acetylcholine, __________ splits acetylcholine into __________ __________ and __________.
Choline is then recycled within the presynaptic neuron.
Definition
1) Acetylcholinesterase
2) Acetic acid
3) Choline
Term
In the removal of acetylcholine, what enzyme works to split up acetylcholine? What is the neurotransmitter split into?
Definition
1) Acetylcholinesterase
2) Acetic acid
3) Choline
Term
In the removal of norepinephrine, the enzyme __________ __________ breaks down norepinephrine recycling it to the presynaptic neuron or allowing it to diffuse away from the synapse.
Definition
1) Monoamine oxidase
Term
What enzyme is responsible for the removal of norepinephrine? Where is the enzyme absorbed after use?
Definition
1) Monoamine oxidase (MAO)
2) Liver
Term
What are the steps for the synthesis and recycling of acetylcholine at a synapse?
Definition
1) Acetylcholine is made from choline and acetyl coenzyme A
2) In the synaptic cleft acetylcholine is rapidly broken down by the enzyme acetylcholinesterase
3) Choline is transported back into the axon terminal and is used to make more acetylcholine
Term
The signal at a synapse can do what to the postsynaptic neuron?
Definition
Either:
1) Excite
2) Inhibit
Term
__________ affect the postsynaptic membrane potential.
Definition
1) Neurotransmitter
Term
What factors can alter the postsynaptic membrane potential?
Definition
1) The amount of neurotransmitter released
2) The amount of time the neurotransmitter is bound to receptors
Term
What are the two types of postsynaptic potentials?
Definition
1) EPSP (excitatory postsynaptic potentials)
2) IPSP (inhibitory postsynaptic potentials)
Term
__________ are graded potentials that can initiate an action potential in an axon.
Definition
1) EPSPs
Term
What are EPSPs?
Definition
1) Graded potentials that can initiate an action potential in an axon
Term
What type of postsynaptic potential uses chemically gated channels?
Definition
1) EPSPs
Term
True or False: Postsynaptic membranes do not generate action potentials.
Definition
1) True
Term
EPSPs bring the resting membrane potential closer to the __________ and therefore closer to an action potential.
Definition
1) Threshold
Term
What occurs during fast EPSPs?
Definition
1) Receptors are ion channels that are opened by neurotransmitter binding
2) Permeable to Na+ and K+; where the Na+ influx is greater than the K+ efflux
3) Net influx of positive charge occurs with brief depolarization
Term
What occurs during slow EPSPs?
Definition
1) Receptor activates G protein
2) 2nd messenger results in change in channel opening
3) Activation of pKA followed by phosphorylation of K+ channel
4) Closing of K+ channel and depolarization occurs
Term
Neurotransmitters binding to a receptor at inhibitory synapses cause the membrane to become more permeable to __________ and __________ ions.
Leave the charge on the inner surface more __________ (flow of __________ out) of the cytosol makes the interior more __________ relative to the exterior of the membrane.
Reduces the postsynaptic neuron's ability to produce an __________ __________.
Definition
1) Potassium
2) Chloride
3) Negative
4) K+
5) Negative
6) Action potential
Term
What are the steps of presynaptic inhibition?
Definition
1) An excitatory neuron fires
2) An action potential is generated
3) An inhibitory neuron fires, blocking neurotransmitter release at one synapse
Term
What are the steps of postsynaptic inhibition?
Definition
1) One excitatory and one inhibitory presynaptic neuron fire
2) Modulated signal in the postsynaptic neuron below threshold
3) No action potential is initiated at the trigger zone
4) No response in any target cell
Term
There is roughly 15 mV __________ to reach the __________ for an action potential.
Definition
1) Depolarization
2) Threshold
Term
Each EPSP and IPSP prduces __________ mV charge.
Definition
1) Roughly 0.5
Term
Roughly how much charge does an EPSP or IPSP produce?
Definition
1) Roughly 0.5 mV
Term
__________ summation is when rapid, repetitive activation of one input summates to threshold whereas __________ summation is when simultaneous activation of several inputs summates to the threshold.
Definition
1) Temporal
2) Spatial
Term
What is temporal summation? Spatial?
Definition
1) Temporal summation is the rapid repetitive activation of one input to summate to a threshold
2) Spatial summation is the simultaneous activation of several inputs to summate to threshold
Term
Multiple graded potentials are integrated at the __________ __________ to evaluate the necessity of the action potential
Definition
1) Axon hilcock
Term
In a __________ __________, many presynaptic neurons converge to influence a smaller number of postsynaptic neurons.
Definition
1) Convergent pathway
Term
The highly branched dendrites of a __________ __________ demonstrate convergence.
Definition
1) Purkinje cell
Term
__________ __________ __________ is a series of impulses in one excitatory fiber together to produce a suprathreshold depolarization that triggers an action potential.
Definition
1) Temporal excitatory summation
Term
__________ __________ __________ are impulses in two excitatory fibers that cause two synaptic depolarizations that together reach the firing threshold triggering an action potential.
Definition
1) Spatial excitatory summation
Term
Activity at a synapse induces sustained changes in the quality or quantity of __________; may be related to __________ and __________.
Definition
1) Connections
2) Learning
3) Memory
Term
What is a key element in potentiation?
Definition
1) Glutamate
Term
What are the six steps of long-term potentiation?
Definition
1) Glutamate binds to AMPA and NMDA channels
2) Net Na+ entry through AMPA channels depolarizes the postsynapic cell
3) Depolarization ejects Mg2+ from NMDA receptor-channel and opens the channel
4) Ca2+ enters the cytoplasm through NMDA channel
5) Ca2+ activates second messenger pathways
6) Paracrine from postsynaptic cell enhances glutamate release
Term
The initial segment of an axon can produce frequent, consecutive action potentials if it remains above threshold. What are the requirements for this to occur?
Definition
1) The next action potential produced when the absolute refractory period is done
2) If there is enough excitatory stimulation during the relative refractory period of the previous action potential
Term
There is a 0.2-0.5 millisecond delay between the arrival of an action potential at the synaptic knob and the effect on the PSM. What is this time reflective of?
Definition
1) Time involved in the Ca2+ influx and neurotransmitter release
Term
In __________ __________, the synapse remains inactive until the neurotransmitter has been replenished.
Definition
1) Synaptic fatigue
Term
What are the four possible ways in which drugs can interfere with synaptic transmission?
Definition
1) Alter the synthesis, axonal transport, storage, or release of a neurotransmitter
2) Modify the neurotransmitter interaction with the postsynaptic receptor
3) Influence the neurotransmitter uptake or destruction
4) Replace a deficient neurotransmitter with a substitute transmitter
Term
What are three drugs that alter synaptic transmission?
Definition
1) Cocaine
2) Tetanus toxin
3) Strychnie
Term
The coca leaf is a plant that contains vital nutrients in addition to numerous __________, including cocaine. As a result, cocaine interferes with the complex relationships of neurotransmitters (inhibiting __________ uptake) and blocks the reuptake of __________ at presynaptic terminals.
Definition
1) Alkaloids
2) Monoamine
3) Dopamine
Term
The __________ __________ prevents the release of the inhibitory neurotransmitter GABA, affecting skeletal muscles.
Definition
1) Tetanus toxin
Term
__________ is a bitter poisonous alkaloid that is obtained from nux vomica and related plants of the genus Strychnos and is used as a poison and medicinally as a stimulant of the CNS. Competes with inhibitory neurotransmitter __________ at the postsynaptic receptor site.
Definition
1) Glycine
Term
What negative effects does cocaine have on synaptic transmission?
Definition
1) Inhibits monoamine uptae
2) Blocks reuptake of dopamine at presynaptic terminals
Term
What negative effects does tetanus toxin have on synaptic transmission?
Definition
1) Prevents the release of the inhibitory neurotransmitter GABA which affects skeletal muscles
Term
What negative effects does strychnine have on synaptic transmission?
Definition
1) Competes with the inhibitory neurotransmitter glycine at postsynaptic receptor sites.
Term
__________ __________ means weakness of the muscle.
Definition
1) Myastenia gravis
Term
__________ __________ is a functional disorder at the synapse between the motor neuron and skeletal muscle; it is an autoimmune disorder.
Definition
1) Myasthenia gravis
Term
What autoimmune disease concerns the synapse between the motor neuron and skeletal muscle? Where in the body can it be found?
Definition
1) Myasthenia gravis
2) PNS
Term
__________ __________ is a disease characterized by decreased stimulation of the motor cortex by basal ganglia, which is normally caused by the insufficient formation and action of dopamine.
Definition
1) Parkinson's disease
Term
What is Parkinson's disease? Where in the body is it found? What is it caused by?
Definition
1) Disease characterized by decrease stimulation of the motor cortex by the basal ganlia
2) The CNS
3) The insufficient formation of dopamine
Term
__________ is a disease characterized by increase dopamine activity in the mesolimbic pathway of the brain.
Definition
1) Schizophrenia
Term
What is schizophrenia characterized by? Where is it found in the body?
Definition
1) Characterized by increased dopamine activity in the mesolimbic pathway of the brain
2) The CNS
Term
Antibodies block or reduce the number of __________ __________ receptors at neuromuscular junctions, resulting in muscle fatigue.
Definition
1) Nicotinic acetylcholine
Term
__________ agents promote the activation of dopamine receptors.
Definition
1) Dopaminergic
Term
__________ __________ prevent the activation of cholinergic receptors.
Definition
1) Anticholinergic
Term
__________ __________ is a cholinesterase inhibitor and increases acetylcholine at the neuromuscular junction.
Definition
1) Edrophonium chloride
Term
How do anti-seizure medications work?
Definition
1) Goal is to decrease propagation of action potentials by decreasing the flow of Na+ and Ca2_ and increases Cl- influx
Term
__________ facilitate GABA binding.
Definition
1) Benzodiazepines
Term
Agonistic action on GABA may account for the __________-__________ and __________ properties.
Definition
1) Sedative-hypnotic
2) Anesthetic
Term
The __________ __________ is a complex network of neurons that form the rapid control system of the body.
Definition
1) Nervous system
Term
__________ __________ of the nervous system include consciousness, intelligence, and emotion.
Definition
1) Emergent properties
Term
The efferent neurons include __________ __________ __________ which control skeletal muscles, and __________ __________ which control smooth and cardiac muscles, glands, and some adipose tissue.
Definition
1) Somatic motor neurons
2) Autonomic neurons
Term
Material is transported between the cell body and axon terminal by __________ __________.
Definition
1) Axonal transport
Term
__________ __________ __________ that can develop into new neurons and glia are found in the ependymal layer as well as in other parts of the nervous system.
Definition
1) Neural stem cells
Term
The __________ __________ describes the membrane potential of a cell that is permeable to only one ion.
Definition
1) Nernst equation
Term
Membrane potential is influenced by the __________ __________ of ions across the membrane and by the __________ of the membrane to those ions.
Definition
1) Membrane potential
Term
The permeability of a cell to ions changes when ion channels in the membrane __________ and __________.
Definition
1) Open
2) Close
Term
Gated ion channels in neurons open or close in response to __________ or __________ signals or in response to __________ of the cell membrane; they also close to inactivation.
Definition
1) Chemical
2) Mechanical
3) Depolarization
Term
The wave of depolarization that moves through a cell is known as __________ __________ __________.
Definition
1) Local current flow
Term
Action potentials begin in the __________ __________ if a single graded potential or the sum of multiple graded potentials exceeds the __________ voltage.
Definition
1) Trigger zone
2) Threshold
Term
__________ graded potentials make a neuron more likely to fire an action potential; __________ graded potentials make a neuron less likely to fir an action potential.
Definition
1) Depolarizing
2) Hyperpolarizing
Term
The voltage-gated Na+ channels of the axon have a fast __________ __________ and a slower __________ __________.
Definition
1) Activation gate
2) Inactivation gate
Term
During the __________ __________ __________, a higher-than-normal graded potential is required to trigger an action potential.
Definition
1) Relative refractory period
Term
The myelin sheath around an axon speeds up conduction by increasing __________ __________ and decreasing current __________.
__________-diameter axons conduct action potentials faster than __________-diameter axons do.
Definition
1) Membrane resistance
2) Leakage
3) Larger
4) Smaller
Term
The apparent jumping of action potential from node to node is called __________ __________.
Definition
1) Saltatory conduction
Term
Changes in blood K+ concentration affect __________ membrane potential and the conduction of __________ __________.
Definition
1) Resting
2) Action potentials
Term
In __________ __________ an electrical signal passes directly from the cytoplasm of one cell to another through gap junctions.
Definition
1) Electrical synapses
Term
__________ __________ use neurotransmitters to carry information from one cell to the next, with the neurotransmitter diffusing across the __________ __________ to bind with receptors on target cells.
Definition
1) Chemical synapses
2) Synaptic cleft
Term
Neurotransmitter receptors are either __________-__________ __________ __________ (ionotropic receptors) or __________ __________-__________ __________ (metabotropic receptors).
Definition
1) Ligand-gated ion channels
2) Metabotropic receptors
Term
What are three ways in which neurotransmitter action is rapidly terminated?
Definition
1) Reuptake into cells
2) Diffusion away from the synapse
3) Enzymatic breakdown
Term
When a presynaptic neuron synapses on a larger number of postsynaptic neurons, the pattern is known as __________.
Definition
1) Divergence
Term
When several presynaptic neurons provide input to a smaller number of postsynaptic neurons, the pattern is known as __________.
Definition
1) Convergence
Term
Synaptic transmission can be modified in response to activity at the synapse, a process known as __________ __________.
Definition
1) Synaptic plasticity
Term
G protein-coupled receptors either create __________ __________ __________ or modify cell metabolism.
Ion channels create __________ __________ __________.
Definition
1) Slow synaptic potentials
2) Fast synaptic potentials
Term
The summation of simultaneous graded potentials from different neurons is known as __________ __________.
Definition
1) Spatial summation
Term
The summation of graded potentials that closely follow each other sequentially is called the __________ __________.
Definition
1) Temporal summation
Term
__________ __________ of an axon terminal allows selective modulation of collaterals and their targets.
Definition
1) Presynaptic modulation
Term
__________ __________ occurs when a modulatory neuron synapses on a postsynaptic cell body or dendrites.
Definition
1) Postsynaptic modulation
Term
__________-__________ __________ and __________-__________ __________ are mechanisms by which neurons change the strength of their synaptic connections.
Definition
1) Long-term potentiation
2) Long-term depression
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