Psych 3313 Questions to help you study cumulative final

What is the function of each part of the Neuron? (dendrite, cell body, axon)

Dendrite: Collect electrical signal

Cell Body: Integrates incoming signals and generates outgoing signals to the axon

Axon: Passes electrical signals to dendrites of another cell or to an effector cell (muscle cell)

What functional impact does the morphology (shape) of dendritic spines have?

greatly increases a dendrite's surface area and is the usual point of contact with axons to form a synapse

What are the major functions of Microglia, Astrocytes, Schwann cells and Oligodendrocytes?

Microglia: Debris cleanup (CNS)

Astrocytes: Structural and nutritional support, isolation of the synapse, debris cleanup, blood-brain barrier, participation in chemical signaling (CNS)

Schwann cells: Myelination of axons (PNS)

Oligodendrocytes: Myelination of axons (CNS)

What is the tripartite synapse?

Presynaptic terminal and postsynaptic terminal surrounded by an astrocyte. Astrocyte helps take-up excess neurotransmitter and form a seal so neurotransmitters are not free-floating.

What is the blood brain barrier?

Astrocytes that act as a filter for the blood entering the brain.

When the neuron is at rest what is the relative concentration of each ion (Na+, Cl-, K+, Ca2+) on the inside and outside of the cell?

Na+: High on outside, low on inside

Cl-: High on outside, low on inside

K+: High on inside, low on outside

Ca+: High on inside, low on outside

When the neuron is at rest what direction does that electrostatic and diffusion forces want to push each ion?

Na+: inward electrical force, inward chemical force

Cl-: outward electrical force, inward chemical force

K+: inward electrical force, outward chemical force

The movement of which ions (inside or outside the cell) results in (depolarization or hyperpolarization)?

Hyperpolarization: efflux of K+, influx of Cl-

Depolarization: influx of Na+

What two factors determine the membrane potential?

Concentration of ions

Concentration of charged proteins

What are the stages of the action potential?

threshold, upswing (rising phase), overshoot, repolarization (falling phase), afterhyperpolarization

Which channels are open at each stage? Which gates are open at each stage?

Resting: Gate 1 (voltage-sensitive) of Na+ channel closed, Gate 2 (not voltage-sensitive) of Na+ channel open, Gate 1 of K+ channel closed

Depolarize: Gate 1 Na+ opens

Repolarize: Gate 2 Na+ closes, Gate 1 K+ opens

Hyperpolarize: Gate 1 Na+ closes, Gate 2 Na+ opens, Gate 1 K+ opens

How do the gates of the voltage gated Na+ channel relate to the absolute and relative refractory period of the action potential?

absolute refractory period: caused by inactivation of voltage-gated Na+ channels.

What is the process by which the action potential propagates down the axon?

Passive conduction, and saltatory conduction in myelinated axons

What role do ligand gated and voltage gated channels play in neuronal communication?

What are two methods by which the signal from a neurotransmitter is ended (in the synapse)?

Neurotransmitter reuptake or degradation

What property of the action potential is the method by which a neurons encodes information?

What is binding affinity?

How likely it is for a ligand to bind to a particular receptor

What is the relative speed of various routes of drug administration?

Injection > Inhalation > Oral > Topical

What are the various 'Sites of Drug Action'?

agonists vs antagonists, look at lecture picture

What is the function/properties of autoreceptors?

What is the function/properties of a PAM/NAMs?

Positive Allosteric Modulators, Negative Allosteric Modulators: bind to allosteric site (noncompetitive site) on receptor

What type of receptors (ionotropic vs metabotropic) does each neurotransmitter system have?

Glutamate

GABA

Acetylcholine, Dopamine, Norepinephrine, Serotonin

What is the function/properties of the NMDA receptor?

Ionotropic Glutamate receptor, requires both ligand (glutamate) binding and membrane depolarization to dislodge Magnesium ion

Gates Na+ and Ca2+

Which receptors do major psychoactive compounds bind to?

Acetylcholine, Dopamine, Norepinephrine, Serotonin

What is the difference between ipsilateral and contralateral?

ipsi = same side

contra = opposite side

What is the difference between afferents and efferents in relation to the spinal cord?

Afferent (Sensory): go toward CNS from sensory receptors

Efferent (Motor): go out from CNS to muscles and organs

What is the difference between the sympathetic and parasympathetic nervous systems?

sympathetic: fight or flight

parasympathetic: rest and digest

How does the process of migration relate to the organization of the layers of cortex?

Cortex assembled inside-out, younger cells form outer layers of the cortex

How is differentiation across the dorsal ventral axis different from differentiation along the rostral-caudal axis?

Dorsal-Ventral influenced by sonic hedgehog (shh) and bone morphogenetic proteins (BMPs)

Rostral-Caudal influenced by hox genes

What is the function of apoptosis in neurodevelopment?

Cells that do not get neurotropic growth factors die, synaptic pruning

How does experience influence neurodevelopment?

Plasticity occurs during critical windows in certain systems such as vision and social behavior

How are critical time points relevant to neuroplasticity?

Critical time windows for vision in cats and social behavior in orphans shows significant difference in brain activity and neuronal concentration depending on experience.

How does myelination progress throughout the nervous system?

Starts from the forebrain and moves rostrally towards the forebrain

Sensory systems are myelinated before motor systems

Majority of myelination occurs early in childhood, but frontal lobe doesn't finish till about 20 years

What different types of axonal degeneration can occur?

Wallerian degeneration: part of axon distal to injury degenerates

Transneuronal degeneration: Neurons that synapse to the damaged neuron degenerate too

What prevents axonal repair in the CNS?

inhibitory molecules in the myelin, and astrocytes that make glial scars

What signals are necessary for the survival of neurons?

neurotropic growth factors

What signals guide circuit formation?

growth cones are attracted to some guidepost cells and repelled by others

What is the function of adult neurogenesis and where does it occur?

very localized and very low rate in subventricular zone and dentate gyrus of the hippocampus

Adult learning and memory involving hippocampus

Decline of neurogenesis associated with cognitive decline

Protective against stress-related depression

Which cells in retina signal using graded potentials?

photoreceptors and bipolar cells

What happens when light strikes a single photo receptor?

Photoreceptor hyperpolarizes, reduced release of glutamate

Predict how light stimuli would impact on-center off-surround bipolar and ganglion cells.

Light in receptive field center: Photoreceptors in center are hyperpolarized, direct input into bipolar cell, bipolar cell is depolarized

Light in receptive field surround: Photoreceptors in surround are hyperpolarized, indirect input into bipolar cell, bipolar cell is hyperpolarized

How does visual information travel from each eye to the cortex?

Contralateral organization of visual field processing

What part of the visual field is sent to each hemisphere?

Information from left visual field processed in right hemisphere

Information from right visual field processed in left hemisphere

The optic nerve carries projections to what brain areas?

Optic Chiasma:

Optic Tract:

Superior Colliculus: Eye movement

or

Suprachiasmatic nucleus of hypothalamus: Daily rhythm

or

Thalamus (Lateral Geniculate Nucleus): Visual perception

Primary Visual Cortex: Cortical Mapping

Understand how the receptive field of a simple cortical cell relates to the entire visual field.

Look at slides diagram lol

Difference between cones and rods

Cones are color sensitive, rods are not

What occurs with hair cell activation?

Hair cells are Mechanoreceptors, depolarization of the hair cells release glutamate

How are hair cells activated (cochlea vs otolithic organs vs semicircular canals)

Cochlea: Vibration of the basilar membrane in the organ of corti bends and activates hair cells

Otolithic organs: Contains micro calcium stones, movement of head causes shift of crystals that activate hair cells

Semicircular canals: Filled with endolymph, hair cells respond to angular movement of endolymph

What parts of the auditory system show a tonotopic organization?

Basilar membrane, Primary auditory cortex,

Vestibular information from vestibular nuclei are sent to which four areas regulating which functions?

Motor Neurons in the Spinal Cord: controls trunk muscles

Extraocular Nuclei: control of eye movements

Somatosensory Cortex (Thalamus): perception of place in space

Cerebellum: coordination of movement and feedback modulation of activity in the vestibular nuclei

Where does the olfactory system send its information? (brain areas and function)

Frontal Cortex: conscious perception of smell

Hypothalamus (Amygdala): motivational and emotional aspects of smell

Hippocampus: odor memory

The somatosensory cortex receives input from which sensory systems?

Touch information

How does pain modulation occur?

Descending modulation of pain

What neurotransmitter is involved in movement?

acetylcholine

What is the difference between upper and lower motor neurons? What are alpha motor neurons? Where are they located? What is their function?

Lower motor neurons act as link between upper motor neurons and muscles

Alpha motor neurons innervate muscle fibers and produce contractions

What are the differences between the stretch (myotatic) reflex, flexor(withdrawal) reflex, and central pattern generators?

Stretch reflex: Monosynaptic (single synapse)

Flexor reflex: Polysynaptic

Central Pattern Generators: Rhythmic firing (not reflex)

What are the functions of the lateral and ventromedial tracts? Which tracts are located in each of these areas?

Ventromedial System: Automatic movement of neck, torso, proximal limb muscles. Overall body posture and gross limb movements

-Reticulospinal

-Vestibulospinal

-Tectospinal

Lateral System: Controls fine movement of hands, feet and distal limb muscles. Voluntary movement

-Corticospinal

-Rubrospinal

What are the functions of the following brainstem nuclei in the context of the motor system: the red nucleus, superior colliculus, vestibular nuclei, and reticular formation?

Red Nucleus: (rubrospinal) involuntary adjustment of limb and hand positioning to help maintain balance

Superior Colliculus: (tectospinal tract) involved in involuntary adjustment of head position in response to visual information

Vestibular Nuclei: (vestibulospinal tract) helps adjust posture to maintain balance

Reticular Formation: (reticulospinal) various involuntary motor activities-Location of many central pattern generators

What are the functions of the basal ganglia?

Condition cortical output and set the gain of movement (amplitude, velocity, etc.)

May be involved in selecting motor programs to carry out a specific task

Inhibitory output of BG may selectively inhibit competing motor mechanisms in order to prevent them from interfering with voluntary movements

In the basal ganglia how does the relative activation of the direct vs indirect pathways change in Parkinson's and Huntington's disease? What happens with the output of the basal ganglia? What is the functional consequence?

Larger response in indirect pathway = Parkinson's

Larger response in direct pathway = Huntington's

Output: Hyperkinesia increase involuntary movement in HD, Hypokinesia reduction of voluntary movement in PD

What are the functions of the cerebellum? What types of deficits are present with damage?

Maintain posture, balance and coordination

Role in sequencing of complex movements (eating, writing, reaching for an object)

Execute smooth pursuit movements (following an object with your eyes)

Informs motor cortex about the direction, force, and timing required to carry out skilled movement

Plays a role in learning of motor skills (error detector)

Likely plays a role in higher cognitive functions (e.g., attention, planning movements)

Planning and programming of voluntary movements especially learned, skillful movements that become more rapid with practice

Damage: Delay in onset of movement, Ataxia, intention tremor

Understand the general circuit by which the cerebellum acts as an error detector.

compares efferent copy of motor plan with sensory feedback from the muscles

What is the organization of cells in the primary motor cortex? How is this organization effected with motor training?

Somatotopically organized (homunculus), Intensive training can change the location and amount of cortex from which movement of a given body part can be elicited by electrical stimulation - "Cortical Plasticity"

What are all of the ways that the premotor area and the supplementary motor areas are different?

Premotor is Externally guided movement (vision), Supplementary is internally guided

Understand how the PMC acts as external cue memory buffer. Understand how the SMA responds to sequences and mental rehearsal.

Activity in PMC cell starts with instruction that shows where to go, not with trigger stimulus that says go there now

Mental Rehearsal of sequences activates SMA

What changes occur in response to cold and hot environmental temperatures?

Posterior hypothalamus responds to cooler core temperatures.

Preoptic area (POA) of hypothalamus responds to higher core temperatures

Look at Lecture diagrams

What hormones are involved in thermoregulation?

Thyrotropin-releasing hormone (TRH): secreted from hypothalamus, acts on anterior pituitary

Thyroid-stimulating hormone (TSH): released by thyrotropic cells in the anterior pituitary, acts on thyroid gland

Thyroid hormone (TH): released by follicular cells, stimulates target cells to increase metabolic activities,

What changes would stimulate the sensation of thirst?

Volume of fluid extracellular and intracellular must be kept within precise limits, water loss in either area = thirst

What role does antidiuretic hormones (ADH) have in the context of the homeostasis of fluid levels in the body.

promotes fluid retention by signaling the kidneys to reduce urine production and by stimulation renin release

What is the role of ghrelin, leptin, insulin and neuropeptide Y, and endogenous opioids in regard to hunger and satiety?

Ghrelin: Manufactured by stomach lining, increase prior to eating, decline after eating

Leptin: Made by adipose tissue, levels drop when fat stores are low, tells hypothalamus if enough fat

Insulin: Made by pancreas, inhibits appetite, helps cells take up sugar

Insulin inhibits Neuropeptide Y neurons in hypothalamus

NPY increases appetite

What is the difference between homeostatic and hedonic control of hunger?

Hedonic is "learnt"

Homeostatic is Hardwired

masculinization/defeminization of animals?

High testosterone

What role do vasopressin and oxytocin receptors play in pair bonding?

High vasopressin = more likely to pair bond

Oxytocin: partner preference in females

How does olfaction effect maternal behavior in virgin rats and in rat moms?

rat moms can smell pup odor

What happens in the absence of light cues?

Circadian rhythm controlled activity continues in absence of light cues

What brain areas and proteins are important for maintaining circadian rhythms?

Per, Tim and Clock are proteins responsible for controlling the firing of the SCN

What molecules/hormones are controlled by the circadian rhythms?

Growth hormone released during deep sleep

Cortisol release is highest in the morning and drops during the day

Melatonin is released only at night (by the pineal gland)

Adenosine accumulates in basal forebrain during waking

What happens in a typical night of sleep (sleep stages)?

What is the difference between awake vs rem vs stage 1-4 (characteristics of EEG waves and functions)

-Stage 1 - Beginning of sleep cycle - light sleep lasting about 5-10 minutes.

-Stage 2 - Bursts of rapid, rhythmic brain activity. Body temperature starts to decrease, and heart slows.

- Stage 3 - Deep, slow brain waves begin to emerge. Transition between light and very deep sleep.

-Stage 4 - Slow wave or Delta Sleep. Deep sleep lasting ~ 30 minutes. EEG shows synchronized delta waves < 4 Hz.

What are the characteristics of REM sleep?

most dreams occur, paradoxical sleep, waves become similar to those when awake, lasts around 10 minutes