Final Exam Flashcards
functional magnetic resonance imaging (fMRI)
A brain-imaging technique that uses MRI to measure changes in blood flow/blood oxygenation associated with brain activity. Good spatial resolution, poor temporal resolution.
electroencephalography (EEG)
A noninvasive technology for recording the electrical fields on the scalp using external electrodes. High temporal resolution, poor spatial resolution
positron emission tomography (PET)
A research technique that detects radioactively-labeled substances (like water or glucose). Good spatial resolution, poor temporal resolution
transcranial magnetic stimulation (TMS)
A safe way to create reversible, “virtual” lesions. Uses a coil with an electric current to create a rapidly-changing magnetic field, which allows us to modify brain activity where the coil is
neuron
A cell in the nervous system specialized for quickly transmitting electrical signals to other neurons. We have ~85 billion
glia/glial cells
Non-neuron nervous system cells that perform a range of supporting functions. At least as many, probably many more, glia than neurons
synapse
The space between pre- and post-synaptic cells
neurotransmitter
a chemical substance that is released at the end of a neuron by the arrival of an action potential and, by diffusing across the synapse, causes the transfer of the action potential to another neuron, a muscle fiber, or some other structure.
receptor
Specialized proteins in the membrane of a postsynaptic cell which neurotransmitters bind to
myelin
A fatty substance on axons which allow electrical signals to reach the ends of neurons faster. Its presence is what creates the appearance of “white matter”
pons
Part of the brain stem. Relays signals between cerebellum and the cerebrum; involved in sleep/wake
midbrain
The middle of three zones in the developing nervous system, becomes midbrain in the brain. Responsible for defensive and reproductive behaviors; visual and auditory reflexes, and is a neurotransmitter source
basal ganglia
A set of closely interconnected gray matter nuclei. Form loops with areas in the frontal cortex. Important in movement, eye movement, thinking, and reward
amygdala
Structure of the limbic system. Involved in rapid evaluation of sensory input; emotional responses to external stimuli (especially fear)
hippocampus
Structure of the limbic system; primary roles are spatial navigation and episodic memory
thalamus
Part of the diencephalon of the forebrain. Relays sensory information to the cortex.
hypothalamus
Part of the diencephalon of the forebrain. Motivates critical drives (fighting, fleeing, feeding, fucking)
cerebellum
Means “little brain,” involved in coordinated movements, balance, associative learning. Has more neurons than the rest of our brain
corpus callosum
Myelinated axons that connect the two hemispheres of the brain; primary purpose is to convey information between hemispheres
cerebrospinal fluid
A fluid which circulates through the ventricles and over the surface of the brain and spinal cord; helps protect the brain and maintain a stable chemical environment for neurons
central nervous system (CNS)
The brain and spinal cord
peripheral nervous system (PNS)
Connects the central nervous system to the rest of the body
somatic nervous system
Controls voluntary movements of skeletal muscles and skin
autonomic nervous system
Controls self-regulated action of internal organs and glands. Divided into sympathetic NS and parasympathetic NS
sympathetic nervous system
“Fight-or-flight” response system; inhibits digestion, speeds up heart rate, increases blood pressure
parasympathetic nervous system
“Rest-and-digest” response system; promotes digestion, slows heart rate, muscles relax
axon
A long, slender extension from the soma of a neuron that conducts signals rapidly across long distances, away from the neuron
soma
The cell body of a neuron
dendrite
Long, branching extensions from the cell body of a neuron that receive signals from other neurons
axon terminal
Branches at the end of the axon, from which neurotransmitters are released
synaptic vesicles
Packages inside the presynaptic neuron which hold neurotransmitters before binding with the membrane and releasing them into the synaptic cleft
resting potential
the electrical potential of a neuron relative to its surroundings when not stimulated or involved in passage of an impulse. About -70 mV
concentration gradient
The difference in concentration between ions outside vs inside the cell. Ions move down the gradient from areas of higher concentration to lower concentration.
electrical gradient
The difference in electrical charge between the inside and outside of the cell. Ions will move down the gradient to areas with their opposite charge.
threshold
The membrane potential that must be reached for a neuron to generate an action potential; usually at -55 mV
action potential
A rapid change/reversal in a neuron’s membrane potential that is used to transmit information from the cell body to the presynaptic terminal
excitatory postsynaptic potential (EPSP)
When the inside of the cell becomes more positive by positive ions flowing into the cell
inhibitory postsynaptic potential (IPSP)
When the inside of the cell becomes more negative, either by bringing in more anions or allowing cations to leave
depolarization
A state in which the electrical charge across the cell membrane is reduced, during the course of an action potential or during communication across a synapse
hyperpolarization
A change in a cell’s membrane potential that makes it more negative. It is the opposite of a depolarization. It inhibits action potentials. Happens after an action potential
voltage-gated channels
Ion channels that allow only certain ions to pass through the membrane. Open when the membrane potential reaches a certain value.
synaptic transmission
When the action potential reaches the end of the axon, Ca2+, which is highly concentrated outside the cell and wants to flow in, comes in through now-open voltage-gated channels. The calcium interacts with vesicles holding NTs, making them sticky and bind to the axon terminal’s wall, where they empty the NTs into the synaptic cleft.
ligand-gated channels
Ion channels which open to allow ions such as Na+, K+, Ca2+, and/or Cl− to pass through the membrane in response to the binding of a chemical messenger (i.e. a ligand), such as a neurotransmitter
degradation
A mechanism for removing neurotransmitters from the synaptic cleft: specific enzymes break apart the neurotransmitters
reuptake
A mechanism for removing neurotransmitters from the synaptic cleft: special protein transporters in the membrane will selectively pull NTs back inside the cell presynaptically, postsynaptically, or into neighboring cells
transporters
Special proteins in the membrane of a cell that complete reuptake of neurotransmitters
glutamate
An amino acid neurotransmitter. Most common excitatory NT in the CNS
GABA
An amino acid neurotransmitter. Most common inhibitory NT in the CNS
dopamine
A monoamine neurotransmitter. Involved in reward system, drugs, motor control, cognition, schizophrenia
acetylcholine
The most common excitatory neurotransmitter in the PNS. Causes muscle contractions. This is the neurotransmitter that Loewi discovered.
serotonin
A monoamine neurotransmitter.. Regulates appetite, sleep, and mood
norepinephrine
A monoamine neurotransmitter. Regulates arousal, alertness, attention
agonist
Increases the effects of NTs
antagonist
Decreases the effects of NTs
antagonist
Decreases the effects of NTs
slow wave sleep (SWS)
Stage 3 of sleep, the deepest stage of non-REM. Associated with the basal forebrain. Brain waves are low frequency, high amplitude (synchronized)
REM sleep
Rapid Eye Movement. A stage of sleep in which dreams occur and the body is paralyzed (aside from small facial muscles), but the eyes exhibit rapid movement. Brain waves at high frequencies, low amplitude, resembles waking a little bit.
sleep cycles through the night
We move through the stages of sleep several times a night. We don’t re-enter stage 3 in the second half of the night, and we spend more time in REM in the second half of the night.
sleep cycles through the night
We move through the stages of sleep several times a night. We don’t re-enter stage 3 in the second half of the night, and we spend more time in REM in the second half of the night.
slow wave sleep is associated with the ___ (brain region)
basal forebrain
REM is associated with the ___ (brain region)
pons
circadian rhythm
A natural internal rhythm (of sleep/wake) that runs on an approximately 24-hour cycle
suprachiasmatic nucleus (SCN)
A region in the hypothalamus in which cells maintain their own 24-hour clock, and serve as the master clock for the body’s circadian rhythms
suprachiasmatic nucleus (SCN)
A region in the hypothalamus in which cells maintain their own 24-hour clock, and serve as the master clock for the body’s circadian rhythms
pineal gland
A gland which produces and releases melatonin. Receives signals from the SCN
theories of sleep
- Restoration
- Survival advantage
- Simulate rare situations
- Information processing
restoration
A theory for why we sleep. Sleep helps restore and repair brain tissue
information processing
Sleep helps us consolidate our memories, restoring and rebuilding old ones
explicit memory
AKA declarative memory. Information that can be consciously recalled and expressed. Divided into semantic and episodic memory
implicit memory
AKA non declarative memory. The kinds of memories you can’t demonstrate verbally that you have. Involves skills and learning that can occur without conscious awareness
declarative memory brain region
hippocampus
procedural memory
A type of implicit memory. Memories for how to perform skills or habits. Major brain region: striatum
associative learning
When two things become paired through experience. Related to amygdala, cerebellum ______?
Henry Molaison
A patient who had his hippocampus removed. Was then unable to form new episodic memories (anterograde amnesia). Also had a small bit of retrograde amnesisa of things right before the surgery
long-term potentiation (LTP)
long-lasting increases in synaptic strength that are induced when the activity of the presynaptic cell consistently activates along with the postsynaptic cell
AMPA receptors
A type of glutamate receptor. Allows Na+ to flow into postsynaptic neuron, depolarizing it and opening up NMDA receptors
NMDA receptors
A type of glutamate receptor. Are usually blocked by magnesium ions, until a high-frequency synaptic input (incoming Na+ from AMPA receptors) unblocks them, allowing Ca 2+ to flow in
frequency
Distance between wave crests/troughs. We perceive different frequencies as different pitches.
pitch
Our perception of a sound’s frequency. High notes vs low notes.
amplitude
Height of the wave. We perceive different sound wave amplitudes as different volumes (loudness)
loudness
Our perception of a sound’s amplitude
outer ear
Everything outside the eardrum
middle ear
Everything between the eardrum and the oval window. Ossicles are part of the middle ear
inner ear
Everything past the oval window. Includes the cochlea and the semicircular canals
pinna
The folds of the outer ear
pinna
The folds of the outer ear
eardrum
the deepest part of the outer ear. Moves from air particles hitting it when they are pushed by soundwaves; it in turn moves the ossicles
ossicles
Three bones in the middle ear that transfer sound wave energy from the ear drum to the oval window
oval window
The gateway to the inner ear; a membrane which is moved by the ossicles
cochlea
fluid-filled part of the inner ear that contains the hair cells
basilar membrane
A membrane
basilar membrane
A membrane that runs along the length of the cochlea. Goes from small and tight at one end to large and floppy on the other end, allowing the fluid vibrations to change by pitch, which further allows the hair cells to move at different pitches
basilar membrane
A membrane that runs along the length of the cochlea. Is exposed to the fluid waves from the oval window. Goes from small and tight at one end to large and floppy on the other end. This means that vibrations of different frequencies will cause different part of the basiliar membrane to vibrate
tonotopic map
The basilar membrane’s shape lets different parts of it vibrate at different frequencies. The small tight base vibrates at high freq, the floppy apex vibrates at low freq.
inner hair cells
The sensory transducers for sound. When the basilar membrane vibrates, the fluid around the hair cells moves them, pulling them away from each other at the tip. This opens ion channels, which is how energy from the outside world is turned into a neural impulse.
outer hair cells
Hair cells in the cochlea that run parallel to the inner hair cells and can shorten and lengthen to improve the signal received by the inner hair cells
tectorial membrane
The flexible membrane above the basilar membrane of the inner ear, into which the tops of the inner and outer hair cells connect
tectorial membrane
The flexible membrane above the basilar membrane of the inner ear, into which the tops of the inner and outer hair cells connect
cochlear nerve
AKA auditory nerve. The branch of the eighth cranial nerve that conducts auditory information from the organ of Corti to the cochlear nucleus in the brainstem
labeled line coding
Different neurons carry different, specific information. The auditory system, the frequency of a sound is encoded by the set of afferent fibers that happen to connect to the hair cells stimulated by that frequency. In this way, the information the fibers carry is “labeled” by its frequency
interaural differences
The differences in the sound percieved by the two ears.
interaural differences
The differences in the sound perceived by the two ears, which can be used to help locate the source of the sound. Time differences between when the sound arrives at each ear, and differences in the volume of the sound heard by the two ears
medial genticulate nuclei (MGN)
A specialized part of the thalamus that is part of the auditory pathway, relaying info from the cochlea to the primary auditory cortex
conduction deafness
Deafness that results from damage to the outer or middle ear, that prevents transmission of sound to the cochlea
sensorineural deafness
Deafness that results from damage to the cochlea (usually hair cells)
cochlear implants
Provide a representation of sounds and can help with understanding speech. Bypass damaged cochleas by directly stimulating the auditory nerve
vestibular system
Provides information about head movements, acceleration, and head position relative to gravity
semicircular canals
Three fluid-filled chambers in the vestibular organ of the inner ear that encode info about head rotation and angular acceleration
somatosensory system
A sensory system that processes tactile stimulation such as touch, vibration, pressure, temperature, and pain from all over the body
mechanoreceptors
Sensory receptors that are triggered in response to movement, stretch, pressure, pr vibration. Found in skin, muscles, tendons, and some visceral organs. Vary in the size of their receptive fields and their ability to adapt to stimuli of different lengths (some fire throughout a long-lasting stimulus, while others fire at the start but slow down as the stimulus continues)
thermoreceptors
Mechanorecptors that relay temperature information. There are “warm” and “cool” thermoreceptors. These receptors sense temperature RELATIVE to body temp. Will get a stronger signal from ice water (very different from body temp) than cool water (closer to body temp.) At extremely high/low temps, pain receptors take over.
nociceptors
Somatosensory receptors that convey information about pain in response to tissue response.
proprioception
Our sense of position and movement of our bodies. Important receptors are muscle spindles and gogli tendon organs
muscle spindles
Important receptor for proprioception. Sit within muscles and sense changes in muscle length
golgi tendon organ
Important receptor for proprioception. Sit between muscles and tendons, and sense changes in muscle tension.
gate control theory
A theory of pain perception that suggests that the amount of pain perceived depends on the relative activity of both the nociceptive and non-nociceptive pathways, with the non-noci pathways able to “close the gate” of pain perception and surpress the input from nociceptive pathways
taste receptor cell
Site of transduction for taste. Arranged on taste buds. We think each taste receptor cell is specialized to sense one specific tastant and transmit that information, but that manny different types of TRCs can be in a single taste bud.
papillae
The bumps we can see on our tongue. Formed from clusters of 1-100 taste buds, which are made up of taste receptor cells.
5 tastants
sweet, salty, sour, bitter, umami
taste sensation vs perception
Taste sensation begins with chemical compounds triggering responses in receptors, but taste perception also involves smell, sense of texture and temperature, etc.
localizing sources of smell
We can use our two different nostrils to sense which direction smells are coming from
pheromones
Chemicals broadcast by animals to transmit information (identity, sexuality) and trigger behaviors from other members of the same species. Detected by the vomeronasal organ. Humans have a nonfunctioning VMO
synesthesia
A perceptual condition of mized sensarions, in which a stimulus in one sensory modality (like vision) involuntarily elicits a sensation in another sensory modality (like hearing)
synesthesia
A perceptual condition of mized sensarions, in which a stimulus in one sensory modality (like vision) involuntarily elicits a sensation in another sensory modality (like hearing)
anosognia
Lack of awareness about a physical impairment (as in a blind patient denying that they’re blind)
transduction
Translation of an external stimulus into a neural signal. A critical early step for all sensory processing
retina
A layered structure at the back of the eye. Composed of (front to back) ganglion cells, bipolar cells, and photoreceptors.
photoreceptors
The sites of transduction in vision. Rods and cones. Capture photons of light and convert it into biochemical signals.
rods
The more numerous photoreceptor. Only one type. Don’t detect color but are more sensitive to light–we rely on rods at night time.
cones
The less numerous photoreceptor. Three types that detect different colors. More concentrated at the fovea. Also better at viewing detail
fovea
A part of the retina where ganglion cells are smaller, allowing more light to reach the photoreceptors. Almost no rods in this region, but tons of cones
bipolar cells
Receive information (in graded signals) from photoreceptors and send it to ganglion cells
ganglion cells
Cells that receive information from the bipolar cells and send it via action potentials to the brain. Their axons make up the optic nerve. May be on-center (respond most to light in the center of their receptive field) or off-center (respond most to light on the periphery of their receptive field)
blind spot
The place where the axons of ganglion cells leave the eye. No photoreceptors
optic chiasm
The point at which ganglion cell axons cross over each other, bringing information about the left visual field to the right visual cortex and vice versa
optic nerve
The axons of ganglion cells, brings light information to the brain. Called the optic tract once it passes the optic chiasm
lateral geniculate nucleus (LGN)
A region in the thalamus which recieves info from the optic tract and projects to the primary visual cortex
striate cortex
AKA primary visual cortex. Contains simple and complex cells. This area helps view lines, making it able to sense orientation, position, movement, and direction
simple cortical cells
Cells in the striate cortex. Receive info from multiple LGN neurons. See the orientation and position of lines.
complex cortical cells
Cells in the striate cortex. Receive info from multiple simple cells. Respond to motion and direction of lines.
ventral stream
The “what” pathway: helps us determine the nature of the stimulus. After visual information is processed in the striate cortex, it goes here or to the dorsal stream.
dorsal stream
The “where” pathway: helps us determine the position of the visual stimulus. After visual information is processed in the striate cortex, it goes here or to the ventral stream.
fusiform face area
An area of the ventral stream specified for viewing faces. Damage here can lead to prosopagnosia
prosopagnosia
Face blindness. Inability to recognize faces.
motion detection
Area V5 in the dorsal stream is responsible for motion detection.
motion blindness
Inability to see things moving–instead, they just appear to change positions
change blindness
We’re bad at discerning differences in images that are similar. This shows that we’re not directly analyzing the visual input, but rather our internal model of what we see.
alcohol
A depressant drug which is a GABA agonist and a glutamate antagonist
caffeine
A stimulant drug which is an adenosine (sleepy) antagonist. Blocks adenosine receptors
nicotine
A drug which is an acetylcholine agonist
ecstacy
A drug which is an agonist of serotonin and dopamine
LSD
A hallucinogenic drug which is a serotonin agonist (especially in the visual cortex)
cocaine
A drug which is a dopamine agonist
heroin
A drug which is an agonist of endogenous opioids
amphetamine
A drug which is very effective at increasing dopamine (and histamine, norepinephrine) levels. It is a dopamine agonist. Increases DA release by reversing transporter molecules, as well as blocking the breakdown of DA
emotion
A combination of physiological , expressive behaviors, and our conscious experience (feelings and thoughts)
limbic system and emotion
The limbic system plays a role in emotion.
two roads to the amygdala
Sensory info is processed by the thalamus and goes either immediately to the amygdala (fast, low road) or to the sensory cortex of the hippocampus and then the amygdala (slow, high road). The amygdala modulates emotional behavior, autonomic responses, and hormonal responses
stress
the process by which we perceive and respond to certain events (stressors) that we find threatening or challenging. Stress is your mental and physical response to stressors.
HPA axis
Hypothalamus–adrenal–pituitary. Our central stress response system. H tells P (via CRH): produce and secrete ACTH, which tells A to secrete cortisol
adrenal gland
Stimulated by the adrenal glands to release epinephrine and norepinephrine. Also release cortisol
norepinephrine (stress response)
receptors concentrated in brain; increase vigilance
epinephrine (stress response)
receptors throughout the peripheral NS; stimulates sympathetic NS
cortisol
A stress hormone released by adrenal glands with long-term effects. Gives muscles glucose, tells immune, reproductive, digestive system to take a break
