Brain, Mind, Behavior Test 2 Flashcards
What do psychoactive drugs do? (and what are two types)
relieve severe symptoms (antipsychotics and atypical antipsychotics)
Antipsychotics (neuroleptics)
a class of drugs that relieve or alleviate symptoms of schizophernia. This is typically done by blocking dopamine D2 receptors
Atypical antipsychotics
act on D2 receptors and/or other receptors. they help relieve symptoms that are resistant to typical antipsychotics.
exogenous substance
from outside the body- have been used for ages to change the functioning of the brain and body
How do neurons process and transmit info?
through electrical and chemical signals
what is a neurotransmitter
an endogeneous (internal) substance that has been released by the presynaptic neuron
action potentials reach the axon terminal- what is this?
this is the presynaptic side of a synapse
action potentials cause the vesicals to release what
releases neurotransmitter into the synaptic cleft
where do molecules bind to neurotransmitter receptors
in the membrane of the postsynaptic cell
what are the 2 possible things that happen to neurotransmitters
they are either broken down by enzymes or brought back into the presynaptic terminal via reuptake (this relies of special transporters)
what is monoamine oxidoase (MAO)
an antidepressent
how does monoamine oxidase (MAO) work?
inhibitors of it prevent the breakdown of monoamines at the sunapses. The accumulation of these transmitters prolongs their activity. This is the huge imporant function of antidepressents (fun fact, you have to follow a specific diet on this stuff tho so like not slay)
how do tricyclic antidepressants work
they block reuptake of serotonin and norepinephrine
how do selective serotonin reuptake inhibitors (SSRI) work
act specifically at serotonergic synapses.
what do receptor proteins do?
recognize transmitters and their mimics
what are the two basic kinds of neurotransmitter receptors
iontropic receptors and metabotropic receptors
ionotropic receptors
quickly change shape and open or close an ion channel when the transmitter molecule binds
metabotropic receptors
alter chemical reactions in the cell. they use a system of second messengers to open an ion channel. may start chemical reactions to alter gene expression
criteria for neurotranmitter classification (5)
- it is synthesized in presynaptic neurons and stored in axon terminals
- it is released when action potentials reach axon terminals
3.it is recognized by receptors on postsynaptic membrane (it is a ligand) - causes changes in a postsynaptic cell
- blocking its releease intereres with a cells ability to affect a postsynaptic cell
anxiolytics (what are 3)?
depressants, barbiturates, and benzodiazepines
depressants
drugs that reduce nervous system activity
barbiturates
early anxiolytics and sleep aids. they depress nervous activity. they are addictive and easy to overdose on (they can literally put you to sleep enough for someone to do surgery)
benzodiazepines
a specific anxiolytic that acts as agonist on GABA (A) receptors and enhances the inhibitory effects of GABA
opium
contains morphine, which is an effective analgesic
what are related to opium
morphine and heroin. they are related and highly addictive
how do opiates work
they bind to opioid receptors in the brain, especially the periaqueductal gray
endogenous opiods
they are enkephalins, endorphins, and dynorphins (which are peptides produced in the brain)
the 3 kinds of opioid receptors
delta, kappa, and mu. They are all metabotropic receptors
how to reverse effects of opiates
drugs that block opioid receptors can reverse the effects of opiates
active ingredient of in cannabis
delta-9-tetrahydrocannabinol (THC)
effects of marijuana
they can vary. relaxation, mood alteration, stimulation, and paranoia
heavy use of marijuana can cause what
respirator problems, addiction, and cognitive decline
what can adolescent use of marijuana can increase what?
schizophrenia
cannabinoid receptors
the brain contains cannabinoid receptors that mediate the effects of compounds like THC
endocannabinoids
analogs of marijuana produced in the brain, such as anandamide
stimulants do what
increase nervous system activity by increasing excitatory input or decreasing inhibitory activity
what do presynaptic adenosine receptors do
normally reduce transmitter release but are blocked by stimulants (such as caffeine), resulting in increased transmitter release.
nicotine is a _________
stimulant
short term affects of nicotine
increases heart rate, blood pressure, digestive action, and alertness
what does nicotine do
it acts as an agonist on nicotinic ACh receptors in the cortex. It enhances some cognitive functions, the ventral tegmental area, and activates reward/addiction pathways
cocaine- what has it been used for
was used in foods as an anesthetic but it is highly addictive and has serious side effects
cocaine- how does it work
blocks reuptake of monoamine transmitters so that they accumulate in synapses throughout the brain, boosting their effects.
synthetic stimulants
have a two step mode of action on monoamines
amphetamine
a synthetic stimulant. It causes a larger-than-normal release of the transmitter at axon terminals. It also interferes with the breakdown of the transmitter. Prolonged use leads to symptoms that resemble those of schizophrenia or brain damage
2 amino acid trasmitters
glutamate and GABA
alcohol stages and how it works
alcohol effects are biphasic- an initial stimulant phase, followed by a depressant. It acts on GABA receptors and dopamine-mediated reward systems.
glutamate
most widespread excitatory transmitter (AMPA and NMDA receptors)
Gamma-aminobutyric acid (GABA)
most widespread inhibitory transmitter. GABAa receptors- ionotropic; inhibitory;allow Cl- ions into the cell
fetal alcohol syndrome
results when pregnant women abuse alcohol with permanent damage to the fetus.
how does alcohol abuse affect adults
alcohol abuse affects the frontal lobes, though the effects are reversible with abstinence
what does binge drinking do
it might cause brain damage and reduce the rate of neurogenesis
hallucinogens
alter sensory perception and produce unusual experiences through diverse neural actions
LSD (acid) how does it work
strongly activates serotonin 5-HT2A receptors in the visual cortex.
effects of LSD (acid)
produces mood changes and feelings of creativity, and thus may help treat some psychiatric disorders
how are mescaline and psilocybin similar
produce strong visual effects
types of peptide neurotransmitters (neuropeptides)
oxytocin, vasopressin
types of amine neurotransmitters
acetylcholine, dopamine, serotonin
types of gas neurotransmitters
nitric oxide, carbon monoxide
Labeled lines
The brain recognizes the senses as distinct because their action potentials travel along separate nerve tracts.
what energy type do all sensory organs (though diverse) use?
action potentials
generator potential
local change in membrane potential which might activate an action potential
sensory transduction
the converion of electrical energy from a stimulus into a change in membrane potential in a receptor cell
all animals have sensory organs containing _______ that sense some stimuli but not others
receptor cells. all animals have sensory organs containing receptor cells that have some stimuli but not others.
pancinian corpuscle
a skin receptor that responds to vibrations and pressure. They are what senses textures
How does the Pacinian corpuscle
stimuli stretch its membrane and cause sodium channels to open. It creates a graded generator potential; if this potential exceeds the firing threshold, an action potential is generated
Von Frey
He helped research the sense of touch. Most of it was wrong but people still talk about it that way. For example, in the next few flashcards, we will talk about how things respond to senses. It is not actually that thing that responds to it, but it is attached to a neuron that responds to it instead. he also found that some areas respond to pressure, some respond to cold, some respond to heat, etc. Buuuut all respond to pain.
Meissner’s corpuscles
respond to changes in stimuli. detect light touch
merkel’s discs
respond to edges and isolated points
ruffini corpuscles
detects stretching of the skin when we move fingers or limbs
free nerve endings
they are in the skin and respond to pain, heat, and cold
sensory events are encoded as what
streams of action potentials
how can you measure the intensity of a stimulus
the number and thresholds of activated cells
somatosensory system
it can determine if body sensations come from inside or outside of the body.
how is stiumulus location determined
its based on a maplike representation of the posisiton of activated recepotrs
receptive field
the area within which the presence of a stimulus will alter a sensory neurons firing rate
sensory adaptation
progressive decrease in the response of a receptor to a sustained stimulation (think sitting in a hot tub of water. its hot at first and then it gets easier)
phasic receptors
display adaptation
tonic receptors
show little or no adaptation
how can sensory information be suppressed
removing the stiumulus and central modulation of sensory modulation
central modulation of sensory modulation
brain actively suppresses some sensory inputs and amplifies others
dorsal column system purpose
delivers touch information
how does the dorsal column system work
receptors send axons through the dorsal spinal cord so that they synapse on neurons in the brainstem. Axons from those neurons cross the midline and they go to the thalamus. Information about each sense is sent to a different region of the thalamus. In the thalamus, this sense is either emphasized or suppressed.
Sensory cortex is organized into what 2 things
Primary sensory cortex and nonprimary sensory cortex
Primary sensory cortex
one of these exists for each modality
nonprimary sensory cortex (or sencondary sensory cortex)
receives direct projections from the primary sensory cortex area for that modality
primary somatosensory cortex (s1)
located in the postcentral gyrus. it receives touch info from the opposite side of the body (cause it crosses over when it comes to the brain) (s1 cells are arraanged in a map of the body- a sensory homunculus)
association areas
areas in the brain that process inputs from different modalities
polymodal
neurons process input from different sensory systems
synesthesia
a condition in which a stimulus in one modality also creates a sensation on another (think thursday and 7 and red and stuff- when you associate something with a color)
pain steps
discomfort associated with tissue damage. pain causes us to withdraw from its source, to recuperate, and to warn others
McGill Pain Questionaire 3 aspects of pain
sensory-discriminative dimension, motivational-affective (emotional) dimension, and overall cognitive-evaluative dimension
nociceptors
peripheral receptors on free nerve endings that respond to painful stimuli
transient receptor potential type M3 (TRPM3)
detects higher temperatives. does NOT respond to capsaicin
TRPV1
responds to pain and does respond to capsaicin
where is TRPM3 found
on A delta fibers
A delta fibers
large myelinated axons that register pain quickly
TRPV1 receptors are on what
thin, unmyelinated C fibers that conduct more slowly, producing lasting pain
anterolatera system (aka spinothalamic)
transmits the sensations of pain and temperature to the brain
how does the anterolateral system work
nerve fibers send axons into the dorsal horns of the spinal cord. they synapse on spinal neurons that project across the midline before ascending to the thalamus. then substaance p (glutamate and a peptide) are relseased within the spinal corse to boost pain signals.
what are the 4 important amine transmitters
acetycholine, dopamine, norepinephrine, and seratonin
acetycholine
plays a major role on transmission in the forebrain. many cholinergic neruons are found in the basal forebrain. disruption of cholinergic pathways interferes with learning and memory
cholinergic
cells that use ACh as their synpatic transmitter
dopamine
important for many aspects of behavior.
mesotraital pathway
important for motor control. orgininates in substantia nigra
norepinephrine
important in control of many behaviors ranging from alertness to mood to sexual behavior.
where are noradrenergic neurons found
in the locus coeruleus and the lateral tegmental area
seratonin
controls many aspects of behaviors including mood and stuff
serotonergetic neruons originate where
along midline of the midbrain and brainstem
many peptides do what
they act as neurotransmitters
opioid peptids
mimic opiate drugs such as morphine and reduce the perception of pain
peptide hormones contribute to what
peptide hormones such as oxytocin and vasopressin contribute to memory and pair bonding
peptide hormones contribute to what
peptide hormones such as oxytocin and vasopressin contribute to memory and pair bonding
how do gas neurotransmitters differ from other neurotransmitters (3 ways)
1) they are produced outside axon terminals (mainly dendrites) and diffuse out of the neuron as soon as they are produced
2) there are no receptors involved; they diffuse into the target cell and activate second messengers
3) it can function as a retrograde transmitter by diffusing from the post synaptic neuron back to the presynaptic neuron.
Ligand
a substance that binds to a receptor
endogeneous ligands
bind to a receptor and activate a change (eg. opens an ion channel)
when a drug binds to the receptor, it is acting as ____. (and vice versa what is it)
an agonist. if it binds without activating and it also blocks it, then it is an antagonist
each transmitter interacts with a variety of different receptor subtypes. How do scientists use this?
Transmitters differ in distribution within the brain and their types. This allows us to design drugs that work on just one or a few receptor subtypes
binding affinity
the degree of a chemical attraction between a ligand and a receptor
efficacy (intrinsic activity)
the ability of a ligand that has binded to activate the receptor
efficacy (intrinsic activity)
the ability of a ligand that has binded to activate the receptor
dose response curve (drc)
a graph of the relationship between drug doses and the effects
bioavailable meaning
free to act on the target
what does the amount of a drug that is bioavailable depend on?
the route of administration
what does the amount of a drug that is bioavailable depend on?
the route of administration
what is the duration of a drugs effect determined by
how it is metabolized
what is the duration of a drugs effect determined by
how it is metabolized
biotransformation
produces active metabolites that may produce side effects
blood brain barrier
tight junctions between the cells of blood vessels in the CNS prevent the movement of large molecules. This can limit drug availability
metabolic tolerance
organ systems become more effective at eliminating the drug (this can happen over time after repeated drug treatments)
functional tolerance
target tissue may alter its sensitivity to the drug by changing the number of receptors. Do this in multiple ways (down or up regulation)
down regulation
in response to an agonist, a fewer number of receptors will respond to drug
up regulation
in response to an antagonist, more receptors will respond to a drug
cross tolerance
tolerance to one drug is generalized to other drugs in its class
how do drugs block transmitter production
(at presynaptic neuron) drugs may block synthesis enzymes, axon transport of raw materials, or the ability to store transmitter
how can drugs block transmitter release
(at presynaptic neuron) drugs can block action potentials from occurring by blocking ion channels- thus blocking transmitter release
autoreceptors can be affected by ___
they can be affected by drugs
drugs and transmitter clearance
(in presynaptic neuron) a drug may block reuptake of a transmitter or block enzymes
drugs may alter postsynaptic systems . They can alter __- and ____
transmitter receptors and intracellular postynaptic processes
how can drugs affect transmitter receptors
- receptor antagonists block postynaptic receptors from being activated.
- receptor agonists bind to receptors and activate them.
how can drugs alter intracellular postynaptic processes
- receptor up and down regulation
- activation of second messenger systems
- activation of genes
look at spinal column systems in the book
do this
transcutaneous electrical nerve stimulation (TENS)
relieves pain by stimulating the nerves around the source of the pain
Naloxone
an opioid antagonist that can block the analgesic effect of TENS. given to ppl who drug overdose
autoreceptor
tells how much transmitter has been released
placebo effect
relief of a symptom even though the treatment is an inert substance
acupuncture
releives pain by inducing endorphin release . stress can activate analgesia systems
reflex
simple, steotyped, and unlearned response to a particular stimulus
acts
complex, sequential behaviors
acts
complex, sequential behaviors
motor plan (motor program)
set of muscles commands that is established before the action occurs
electromyography (EMG)
records the electrical activity of muscles
how do muscles and skeleton work together to move body
tendons connect muscles to bone in a reciprocal function. when one group contracts, it stretches the other. They are antagonistic
striate muscle
this is what skeletal muscles are made of. They are overlapping layers of myosin and actin, which make them appear striped.
motor neurons
come from spinal cord and brain stem
what happens at the nueromusclular junction
ach is released
one molecule of ach is equal to what
one twitch
more firing means what
faster movement
proprioception
the collection of information about body movements and position
proprioception
the collection of information about body movements and position
muscle spindle
a capsule, buried in other muscle fibers, that contain intrafusal fibers. It resonds to stretch.
golgi tendon organs
sensitive to muscle tension
premotor cortex
guided by external events
supplementary motor area (SMA)
important for initiation of movement sequences
