exam #2 Flashcards
agonist
ENHANCE the activity of a neurotransmitter
≠ EPSP
antagonist
REDUCE the activity of a neurotransmitter
≠ IPSP
how does Botox work at the synapse?
it’s an antagonist. decreased ACh at the neuromuscular junction
how does cocaine work at the synapse?
it’s an agonist. it keeps DA in the synapse longer
Metabolic tolerance
changes in metabolic enzymes
example of metabolic tolerance?
ALDH levels are increased in chronic drinkers
Cellular tolerance
changes in brain cells
example of cellular tolerance?
decreased receptor density
learned tolerance
changes in behavior
examples of learned tolerance?
alcohol use and beam walking in rats, heroine users and overdosing
what neurotransmitter system is involved with addiction?
mesolimbic dopamine system
Anterior (rostral) direction
toward the head
Posterior (caudal) direction
toward the tail
ventral direction
toward the belly
dorsal direction
toward the back
ipsilateral
structures on the same side of the midline
contralateral
structures on opposite sides of the midline
Meninges
3 protective membranes that surround the brain and spinal cord
Dura mater
tough outermost layer (meninge)
pia mater
delicate innermost layer (meninge)
Arachnoid membrane
lies between dura mater and pia mater (meninge)
2 division of the automatic nervous system?
sympathetic nervous system and parasympathetic nervous system
sympathetic nervous system
arouses the body for action, “fight or flight” response
parasympathetic nervous system
“rest and digest” response, opposes the sympathetic response
what kind of information travels along the dorsal portions of the spinal chord?
sensory info (body to the brain)
what kind of information travels along the ventral portions of the spinal chord?
motor info (brain to body)
what are the 3 divisions of the hindbrain?
medulla, cerebellum, pons
medulla
oldest part of the brain, control vital functions (like heart rate and breathing), contains several nuclei
cerebellum
“little brains”, contains the most neurons, involved in movement/balance
pons
bridge….connects cerebellum to the rest of the brain, contains several nuclei
tectum
located in the midbrain…the roof
superior colliculi
visual part of the tectum….. ex: friend waving across the street
inferior colliculi
sound part of the tectum…..ex: loud bang in the back of the classroom
5 divisions of the forebrain?
cortex, basal ganglia, limbic system, thalamus, hypothalamus
cortex
involves in sensation and movement & higher-order processes
basal ganglia
Involved in the planning and execution of voluntary movement, important for procedural memory
limbic system
Involved in controlling emotions and in learning and memory
thalamus
The brain’s greyhound station
‘Director’ of sensory information
hypothalamus
Directs the autonomic nervous system
Contains regulatory centers for Eating, drinking, Sexual behavior, Sleep, Temperature
Direct link with the blood supply via pituitary gland
what are the 4 principles common to all sensory systems?
Sensory receptors
Neural pathways
Coding and representation
Perception
general pathway for all sensory information?
Receptor > Relays > Cortex
what is sensation?
a neural representation of the physical world provided by a sensory system
what is perception?
subjective experience of sensation
Wavelength (λ)
distance between 2 successive peaks
Short λ
blues
medium λ
greens
long λ
reds
low peak on a light wave?
dim
high peak on a light wave?
bright
2 varieties of photoreceptor present in the retina?
rods and cones
rods
Scotopic More numerous than cones Responsible for night vision Responsible for movement vision Located in the periphery Only 1 type of photopigment
cones
Photopic System Less numerous than rods Responsible for day vision Responsible for color vision Responsible for visual acuity Located in the fovea 3 types of photopigment
transduction in the rod…..dark?
- Rods contain the photopigment, rhodopsin
- Rhodopsin makes a molecule that binds and opens Na+ channels, keeping the rod constantly depolarized
- This depolarization leads to glutamate release
transduction in the rod…..light?
- Rhodopsin absorbs photons and changes structure
- Rhodopsin breaks apart
- No longer keeps Na+ channels open
- The rod hyperpolarizes
- Rods decrease their release of glutamate
3 types of retinal ganglion cell?
Magnocellular (M cells)
Parvocellular (P cells)
Koniocellular (K cells)
Magnocellular (M cells)
carries rod information
Parvocellular (P cells)
carries cone information from L and M cones
Koniocellular (K cells)
carries cone information from S cones
right visual field is processed by the ________.
left hemisphere
left visual field is processed by the ___________.
right hemisphere
Lateral geniculate nucleus (LGN)
In the thalamus of the forebrain….Relay stop for vision. information is kept segregated in layers
Simple Cortical Cells
responsible for detecting shape
complex cortical cells
responsible for detecting movement
blobs
respond to color information
primary visual cortex organization?
Cells are organized into columns
Columns are all responsible for similar functions
-Orientation columns
Each column responses to a particular orientation
Neighboring columns respond to orientation shifted 10°
-Ocular dominance columns
Each column responses to input from a particular eye
Full set contains a column for the right eye and a column for the left eye
what kind of information is carried up the dorsal stream and where does it end up?
Receives MAGNOcellular information…. projects to Area MT
what kind of information is carried up the ventral stream and where does it end up?
Receives PARVOcellular information ….. projects to Area IT
Bottom Up Hierarchy Theory
-Complex responses are generated from from simpler input
e.g. dot of light >bar of light > shape > a box
- “Feature detector neuron”
e.g. ‘grandmother’ cell
‘Halle Berry’ cells in the temporal lobe
monocular depth cues
Interposition…. guy on horse
Linear perspective….hallway
Chiaroscuro…… shaded ball
Motion parallax……looking out on the train
what theory explains the illusion of afterimages?
trichromatic theory
What is the physical stimulus of hearing?
the sound wave
Frequency (λ) of a sound wave
Measured in Hertz (Hz)
Codes for PITCH
(Low λ = Low pitch)
(High λ = High pitch)
Amplitude of a sound wave
Measured in Decibels (dB)
Codes for LOUDNESS
(Low amplitude = soft)
(High amplitude = loud)
complexiity of a sound wave
Pure (single λs) vs complex (mixture of λs) tones
Codes for TIMBRE
function of outer ear
to direct sound to the inner ear
function of inner ear
transduction
function of middle ear
to amplify sound
age-related hearing loss
Affects higher λs
Exposure to loud sounds
Poor circulation
hearing loss: conduction loss
Due to problems in the outer or middle ear
hearing loss: damage loss
Can occur anywhere along the auditory pathway
binaural neurons
Increased firing when info from each ear arrives simultaneously
Decreases as difference grows
