PART 3 Flashcards
Kinematics
the parameters that describe the spatiotemporal form of movement such as direction, amplitude, speed, and path
Kinetics
casual forces and muscle activity
Class I drugs
they bind to GPCRs in the presynaptic site
and block their release of GABA into the dopamine neurons
Class II drugs
they bind to ion channels, which increases the influx of ions and thus causes hyperactivity of dopamine neurons
Class III drugs
Cocaine: blocks dopamine transporter, thus inhibiting reuptake of dopamine
amphetamine: pretends to be dopamine and it is reuptake and it saturates the transporter
EEG
Electroencephalography: cortical neural activity
EMG
muscle activity
EOG
eye movement
wakefulness area
posterior hypothalamus
sleep area
anterior hypothalamus
narcolepsy
it is the inability to stay awake - feeling fatigue and sleepiness
implicit memory
(implicit)
no conscious recall
habits, motor skills
explicit memory (declarative)
requires conscious recall
- facts, events, spatial memory
semantic vs. episodic
types of explicit
- semantic: facts
- episodic: events
place cells
a neuron that selectively fires when the animal is in a particular location
- some cells may only fire when the subject is searching for a specific location
- place fields rotate with the environment
Grid cells
a neuron that selectively fires when an animal crosses the intersection points of an abstract grid map of the local spatial environment
- it allows the animal to locate its body within an external coordinate system
Features:
- spatial phase of nearby cells
- location/alignment according to environment
- as you move more ventral: fields are more dispersed
Head direction cells
no place fields but they fire when head turns in specific directions –> this can be shown in polar plots
Border cells
a neuron that selectively fires when an animal arrives at the perimeter
Does hippocampus only represents space?
- many cells in the hippocampus encode space (Grid cells allows for an animal to locate its body within an external coordinate system, place cells fire at a specific location, head direction cells fire at specific head turning, and border cells fire along border)
- but hippocampus also encode time –> this was shown during wheel running in the delayed alteration memory task, place cells fired at a specific time (sequence of events) - even though there is not change in location, they fire at a given time
sleep comsolidation
- during experience, cells fire as animal moves, creating a patter of cells firing
- during Non-REM sleep, the same sequence is replayed which may explain consolidation of hippocampal memory
prefrontal cortex damage
- motor planning, gaze, speech
- loss of divergent thinking
- impaired social behavior, personality change
- impaired response inhibition,
- inability to wait for delayed reward
stoop task
–> resolving conflict: it is difficult to name the ink color of a color word if there is a mismatch between ink color and word.
- people with PFC lesions have a harder time with resolving this task
Wisconsin card sorting test:
–> tests for flexibility
Stimulus cards are shown to the participant, who is then instructed to match the cards.[3] They are not given instructions on how to match the cards but are given feedback when the matches they make are right or wrong
mental sketch pad
temporarily hold information during a task –> inhibition of inappropriate thoughts and emotions
gating/filtering
PFC function mechanism that enhances goal-directed activations, and inhibits irrelevant activations
active maintenance
patterns in the PFC represent goals and means to achieve them, provide bias signals to other brain
dorsal PFC
attention, working memory
ventromedial and orbitofrontal cortex
decision-making, inhibitory control, planning
anterior cingulate
an executive attention system that responds to task difficulty, novelty, error detection
top-down process
the voluntary allocation of attention to certain features, objects
- this modulates our perception
Frontal eye field (FEF)
part of the PFX –> important source of top-down attention signal
V4
visual area where the effect of attentional modulation is often observed
working memory
- this type of short-term memory
- depends on persistent activity in parts of the brain
- monkey must remember what side is related to a food reward
- lesions in PFC cause deficit
mirror cells
cells found in the premotor cortex which fire when animal/human both observes and does the action
convergence (M1 stimulation)
multiple inputs merge into the same cell
- multiple stimulation sites of the M1 can activate the same muscle
divergence (M1)
One neuron has multiple outputs
- activating the same site can stimulate different muscles
- M1 stimulation in one site can active muscles in shoulder and writs
motor cortical neuron information encoding
the brain first plans a chosen movement by the first calculating the kinematics then the required kinetics
what does the motor neuron spiking indicates?
They indicate both force (intensity) and position/direction (population activity)
* kinematics and kinetics
half-center oscillator
the most common central pattern generator in the spinal cord
- two neurons inhibit each other which creates a rhythmic
peripheral feedback theory
proposed by William james:
our emotion/experience is a response to the physiological changes
- first is bodily response and then emotion
ventromedial PFC
- important area for social emotions
- phineas cage had a damaged PCF which resulted in social deficits and abnormal emotional response
amygdala
plays a key role in fear
- unconditioned (innate)
- conditioned (learned)
CS
think of it as something that must be paired with another stimulus to elicit a response
* NEUTRAL
indirect pathway (amygdala)
stimulus reaches the thalamus which relays this information to the cortex –> this information the reaches the LA –> CE to give a more detailed conscious response
direct pathway
stimulus reaches the thalamus –> direct relay of info to amygdala to create unconscious reaction
CE
composed of the medial and lateral
- Medial CE is the main output to other brain areas
- CEL neurons modulate the response of CEm
CEm
- main output from amygdala
- firing rate increases in response only after learning
(compared to habituation, where there was low firing rate to cs)
antidromic activation
this is a method that is used to confirm that a neuron being recorded from projects to the structure of interest
CEl
lateral central amygdala has both fear on and fear off neurons
* they are inhibitory neurons that send GABA input to CEm neurons
what areas are responsible for sleep vs. wake?
wake = posterior hypothalamus, rostral midbrain
sleep = anterior hypothalamus, basal forebrain
Sleep-wake homeostasis
keeps track of your need for sleep. The homeostatic sleep drive reminds the body to sleep after a certain time and regulates sleep intensity. This sleep drive gets stronger every hour you are awake and causes you to sleep longer and more deeply after a period of sleep deprivation.
circadian rhythms
direct a wide variety of functions from daily fluctuations in wakefulness to body temperature, metabolism, and the release of hormones. They control your timing of sleep and cause you to be sleepy at night and your tendency to wake in the morning without an alarm. Your body’s biological clock, which is based on a roughly 24-hour da
sleep mechanism
the VLPO is activated, they have GABA neurons that inhibit the wake-inducing neurons of the ascending pathway
wake mechanism
production of orexin is important to excite the ascending arousal system
ob gene
encodes for leptin
- leptin inhibits eating
db gene
encodes for the receptor that responds to leptin
feeding circuit
two populations of neurons are found in ARC
AgRP neurons (GABA) –> PVH
AgRP –> POMC –> PVH/PBN
modulation of ARC neurons
sensory cues are enough to alter neuron activity –> however this is only a single-trial transient activity
nutrition, on the other hand, provides an innate sustained respose
modulation of AgRP neurons
detection of food inhibits AgRP as a way to modulate activity, but this activity was momentary
- the presentation and accessibility of food was important for stable activity changes
working memory
it last for a few minutes and rehearsal is necessary
- brain site: the prefrontal cortex
short term memory
rehearsal not required, it can lastt for minutes of hours
site: hippocampus
memory consolidation
- occurs by sleep, recall
site: hippocampus involved in this process based on HM studies
Long-term memory
lasts days or a lifetime
site: neocortex
replay hypothesis
this refers to the hippocampal replay that transfers information from the hippocampus to the neocortex
- wave ripple may be important : spontaneous neural activity during sleep
Grid cell
- found in the medial entorhinal cortex
- fires whenever an animal is at any regulatory spaced positions –> allowing the animal to locate its body with a space
- grid size and spacing changes along the dorsal ventral
head direction cells
no clear place field but fire only when there is a clear direction of head
border cells
fire along borders
place cells
fire when the animal is at a specific place in tmen
