Exam 2 Flashcards
(neurochemical)
- released at directed synapses
- act on neurons in immediate vicinity
neurotransmitters
(neurochemical) (two)
- non-directed synapses (volume-transmission)
- act on more distant neurons
neuromodulators and neurohormones
(neurochemical)
diffuse away from point of release
neuromodulators
(neurochemical) travel in blood supply
neurohormones
Acetylcholine synthesis
Choline + Acetate via enzyme ChAT
Acetylcholine receptors
nicotinic (ionotropic)
muscarinic (metabotropic)
Acetylcholine degradation
reuptake or broken down by enzyme AChE
Acetylcholine role in peripheral nervous system (autonomic)
both pre-ganglionic, parasympathetic post-ganglionic
Acetylcholine role in peripheral nervous system (somatic)
neuromuscular junction (think botox)
Acetylcholine role in central nervous system
projections from basal forebrain to hippocampus and amygdala; septal area (part of limbic system); brainstem
Acetylcholine behaviors
autonomic functions, movement, learning and memory
Acetylcholine clinical conditions
Alzheimer’s, myasthenia gravis (effects neuromuscular junction), schizophrenia (lots of chemicals involved in schizo)?
lose cells in these area
cholinergic areas
cholinergic projections of the human brain
basal forebrain
pons and midbrain
- binds nicotine
- blocked by curare
- ionotropic
- response is fast and brief
- located at NMJ, ANS, CNS
- excites target cells
- postsynaptic
Nicotinic ACh Receptors
plant based poison
curare
- binds muscarine
- blocked by atropine
- metabotropic./GPCR
- response is slow and prolonged, amplified
- found on Myocardial and smooth muscle, CNS
- mediates inhibition and excitation in target cells
- both pre- and postsynaptic
Muscarinic ACh Receptiors
Small molecule neurotransmitters: monoamine neurotransmitters
- catecholamines
- indoleamines
- histamine
- include: dopamine, norepinephrine, epinephrine
- synthesized from tyrosine
catecholamines
- include: serotonin, melatonin
- serotonin is synthesized from tryptophan
indoleamines
catecholamine synthesis rate limiting step
Tyrosine Hydroxylase
Dopamine (DA) role in PNS
neuromodulator for other neurotransmitters
Dopamine role in CNS
- substantia nigra (SN) -> basal ganglia
- ventral tegmental area (VTA) -> hippocampus, amygdala, nucleus accumbens, and frontal lobe
Dopamine behavior(s)
movement control, reinforcement, planning
Dopamine clinical conditions
Parkinson’s disease, schizophrenia, drug abuse
Dopamine synthesis
- tyrosine hydroxylase is rate-limiting step
- dopa decarboxylase converts L-Dopa into dopamine
Dopamine receptors
- D1 D5 = stimulatory G-protein coupled receptors
- D2 D3 D4 = inhibitory G-protein coupled receptors
Dopamine degradation
enzymes Monomine oxidase (MAO), catechol-O-methyl transferase (COMT), and aldehyde dehydrogenase, acting in sequence to break down dopamine
finite resource. determines how much of these diff compounds you can produce
rate limiting step
area involved in decision making/reward
Ventral Tegmental Area (VTA)
precursor to Dopamine
L-Dopa
D1 family (D1 and D5)
beginning and end
D2 family (D2 D3 and D4)
all metabotropic
D2 is important in ______
Schizophrenia
what breaks down catecholamines?
COMT
Norepinephrine: role in PNS
autonomic: sympathetic post-ganglionic synapses
Norepinephrine: role in CNS
widespread projections from locus coeruleus (Pons) {blue spot. widespread projections to rest of brain}; medulla, hypothalamus
Norepinephrine: behavior(s)
arousal and vigilance, mood
Norepinephrine: clinical conditions
Depression, mania, PTSD
Norepinephrine: synthesis
dopamine beta hydroxolase converts DA into NE
DA
Dopamine
NE
Norepinephrine
Norepinephrine: receptors
Alpha and Beta
Norepinephrine: degradation
enzymes MAO, COMT, and aldehyde dehydrogenase, acting in sequence to break down norepinephrine
- slow heart down
- off label use
- alter physical effects of sympathetic nervous system
Betablockers
Locus Coeruleus
arousal, stress, anxiety, mania
- relatively minor role in brain, strong neurohumoral effect
- adrenergic neurons
- regulation of blood pressure, eating
Epinephrine/Adrenaline
Serotonin(5HT): role in PNS
enteric: digestive motility
Serotonin(5HT): role in CNS
widespread projection from Raphe nucleus (pons) to brain and spinal cord
Serotonin(5HT): behaviors
sleep-wake cycles, appetite, mood, aggression, social rank
Serotonin(5HT): clinical conditions
depression, OCD, alcoholism
Serotonin(5HT): synthesis
made from tryptophan
Serotonin(5HT): receptors
at least 15 types and sub-types
most are metabotropic, can be excitatory or inhibitory
Serotonin(5HT): degradation
- reuptake (why SSRIs are so effective)
- monamine oxidase
Raphe Nuclei
sleep/wake cycles, depression
in the brain neurotransmitter: regulates sleep, hormonal secretion, memory formation, and brain arousal
Histamine
Benadryl
anti-histamine helps w/ allergic reactions. makes you feel tired and drowsy most of the time
Amino Acid Neurotransmitters
GABA and Glutamate
principle inhibitory NT
mood. seizure threshold
GABA
principle excitatory NT
long term mem. may be associated w/ neurotrauma
Glutamate
- off switch
- main inhibitory NT
- always votes no
- tied to anxiety
GABA
- on switch
- yes vote
- main excitatory NT
Glutamate
- product of Kreb’s Cycle
- terminated by high affinity uptake systems in neurons and astrocytes
Glutamate synthesis and removal
Glia: Glutamine synthesis –>
glutamine –> neuron: Glutamate
Glutamate receptors: ionotropic
AMPA
Kainate
NMDA
Glutamate receptors: metabotropic
mGluRs
Glutamate receptors(ionotropic) most common. opens sodium channel.
AMPA
Glutamate receptors(ionotropic) opens sodium channel. rare.
Kainate
Glutamate receptors(ionotropic) opens channel for sodium and calcium. special.
NMDA
GABA is synthesized from ________ in reaction catalyzed by ___
- glutamate
- GAD
____ converts glutamate into GABA. inhibitory.
GAD
GABA is terminated by
high affinity uptake systems in neurons and glia
GABA receptors: synthesized from __________
glutamate
- GABA receptor
- ionotopic
- made up of 5 subunits
- Cl ion channel
- has multiple binding sites including benzodiazepines, barbiturates, and ethanol
- more common
GABA A
- GABA receptor
- metrabotropic
- gates K+ channel
GABA B
Glycine: role in CNS
- major inhibitory NT in spinal cord interneurons
- lesser role in brain
- excitatory co-activator at NMDA Glutamate receptor
Glycine: behavior(s)
sleep/wake cycles
Glycine: toxins
strychnine
act in the CNS and in connections between autonomic neurons and the vas deferens, bladder, heart, and gut
ATP and Adenosine
is associated w/ pain perception and sleep-waking cycles
ATP
inhibits the release of namy neurochemicals, correlated with drowsiness
blocked by caffeine
adenosine
more __________ that builds up the more sleepy you feel
adenosine
small molecule NTs are synthesized here
axon terminal
do small molecule NTs recycle vesicles?
yes
small molecule NTs activation`
moderate action potential frequency
small molecule NTs deactivation
reuptake or enzymatic degradation
Neuropeptide synthesis takes place
in cell body; require transport
Neuropeptides recycle vesicles?
no
Neuropeptide activation
high action potential frequency
Neuropeptide deactivation
diffusion away from the synapse or enzymatic degradation
Neuropeptides
- Endorphins
- Substance P
- Insulin and Cholecystokinin
- Oxytocin and Vasopression
- Neuropeptide
- neuromodulators that reduce pain and enhance reinforcement
- “opium within”
- feelings of well-being
endorphins
- Neuropeptide
- transmitter in spinal cord neurons sensitive to pain
Substance P
- Neuropeptides
- digestive functions
Insulin and cholecystokinin
- Neuropeptides
- neuromodulators and neurohormones
- relationships; levels influence whether species is monogamous or not
Oxytocin and vasopression
the cuddle hormone
oxytocin
learning and memory; Alzheimer’s disease; muscle movement in the peripheral nervous system
ACh (Acetylcholine)
reward circuits; motor circuits involved in Parkinson’s disease; schizophrenia
DA (Dopamine)
arousal; depression
NE (Norepinephrine)
depression; aggression; schizophrenia
5HT (serotonin)
learning; major excitatory neurotransmitter in the brain
GLU (glutamate)
anxiety disorders; epilepsy; major inhibitory neurotransmitter in the brain
GABA
pain; analgesia; reward
endorphins
diffuse through membranes and interact with intracellular receptors. can transmit info from the postsynaptic to the presynaptic neurons (retroactive)
gaseous neurotransmitters
Two gaseous NTs
- nitric oxide
- carbon monoxide
- found in CNS and PNS, smooth muscle
- relaxes smooth muscle cells in blood vessels
- erection
nitric oxide
colorless, odorless. undetectable by humans
- low doses: hallucinations and paranoia
- high doses: can kill you
carbon monoxide
any substance that alters the body or its functions
drug
relationship between concentrations of drug and biologic effects. (what drugs do to the body)
pharmacodynamics
what the body does to drugs
- absorption
- distribution
- metabolism
- excretion
pharmacokinetics
ED
effective dose @ 50% of the population
plateau. more drug is not going to have more difference at _________
saturation
characteristics of drugs
- affinity
- potency
- efficacy
tenacity w/ which (how well) a drug binds to its receptor
affinity
fits perfectly to receptor
high affinity
fits but not as perfect of a match
medium affinity
doesn’t bind very well
low affinity
affinity is a property/characteristic of the ______ not the _________
drug; receptor
amount of drug required to produce a certain response
potency
want higher ______ so can have a lower dose to get desired effect (lower dose leads to less likelihood for side effects)
potency
property of a drug that determines its ability to produce its biological effect
efficacy
more _______ leads to more response
efficacy
types of drugs
- agonist
- antagonist
- mimics or enhances the effect of a neurotransmitter
- activate receptor
- partial, full, or inverse
- block reuptake or degradation
agonist
- blocks or decreases the effect of a neurotransmitter
- block receptors without activating
- competitive vs non-competitive
- decrease availability of neurotransmitter by reducing production or release
antagonist
presynaptic drug actions
- neurotransmitter production
- neurotransmitter storage
- neurotransmitter release
manipulating the synthesis of a neurotransmitter will affect the amount available for release
neurotransmitter production
interfering with the storage of a neurotransmitters in vesicles within a neuron
neurotransmitter storage
drugs can modify the release of a neurotransmitter in response to the arrival of an action potential
neurotransmitter release
post synaptic drug actions
postsynaptic receptor effects
- can mimic the action of a neurotransmitter at the site (agonist)
- can block the synaptic activity by occupying a binding site (antagonist)
- can influence the activity of the receptor
postsynaptic receptor effects
drug actions: removal effects
- reuptake effects
- enzymatic degradation -deactivation of neurotransmitters
cocaine, amphetamine, and Ritalin inhibit ________ _______
dopamine reuptake
SSRIs (Prozac) inhibit _________ _______
serotonin reuptake
organophosphates interfere with _______
AChE
enzymatic degradation
drug effects are influenced by
- body weight
- sex
- genetics
- user expectations influence drug effects
- can result in real biochemical and physiological effects in the brain
- needs double-blind experiments
placebo effects
decreased response to drug with repeated use
tolerance
reduction in amount of drug that reaches site of action
metabolic tolerance
reduction in reactivity of sites of drug action
- receptor down regulation (less)
- receptor up regulation (more)
functional tolerance
learned tolerance
context specific
occurs when substance use is discontinued; opposite of the effects caused by the discontinued drug
withdrawal
- characterized by a compulsive need to re-administer a drug despite harm to user
- the dopamine reward system, including nucleus accumbens
- result of complex physical and environmental variables = extremely hard to treat
addiction
increase alertness and mobility
stimulants
list of stimulants
- caffeine
- nicotine
- cocaine
- amphetamine
adenosine antagonist
caffeine (stim)
acetylcholine nicotinic receptor antagonist
nicotine (stim)
dopamine floods synapse, dopamine reuptake inhibitor so dopamine in synapse longer
cocaine (stim)
stimulates release and inhibits reuptake of dopamine and norepinephrine
amphetamine (stim)
decrease activity of CNS
depressants
list of depressants
- opioids
- alcohol
reduced release of GABA, less inhibition on DA neurons so more DA into synapse
opioids
GABA A agonist, increases chloride influx.
Glutamate antagonist, reduces excitation
alcohol
cause perceptional distortions
hallucinogens
list of hallucinogens
- marijuana
- LSD
- ecstasy
- ketamine
- PCP
active ingredient THC is an endogenous cannabinoid receptor agonist
marijuana
serotonin agonist
LSD
stimulates massive release of serotonin (and some oxytocin). taken up by serotonin transporters, reverse flow of serotonin, toxic to serotonin neurons
ecstasy (molly)
NMDA glutamate antagonist
ketamine
NMDA glutamate antagonist, nicotinic Ach antagonist
PCP (angel dust)
DNA –> RNA –>
proteins
candidate gene
look for specific gene associated with specific trait. spotlight search
genome-wide
large scale. zoomed out.
approx. ____________ genes in the human genome
20,000
__ autosomes pus X and Y
22 (46 diploid)
genes have ____ and _____
exons and introns