Exam 3 Flashcards
What states of consciousness are associated with alpha, beta, and delta waves?
Alpha: associated with normal, awake mental activity
Beta: associated with heightened arousal and attention(shows Desynchrony)
Delta: associated with deep sleep (stages 3 and 4) –
What are Characteristics of REM sleep?
Rapid Eye Movement (REM) sleep, got its name because the eyes dart back and forth during this stage. It is the stage during which narrative dreams occur; marked by “awake”-like EEG forms (e.g., beta activity); no muscle tone; 90 minutes after beginning of sleep
***Describe activity in the reticular activating system during arousal, sleep, and REM.
Arousal: active RAS (Neurons in the RAS produce acetylcholine, then release it into the thalamus to activate it)
Slow Wave Sleep: inactive RAS
REM: active RAS (RAS contains neurons, called REM-On cells, that are active only during REM sleep)
***What is the Activation-Synthesis hypothesis?
“Activate it, then put it together”
During dream sleep, increased neural firing in RAS activates the Thalamus—>Projection neurons in the Thalamus randomly activate different cortical regions—>Active cortical regions generate diverse sensory images and thoughts—>Other cortical areas (likely frontal cortex) tries to make sense of it all by synthesizing the diverse images into a narrative story or dream.
***What is the role of the ventrolateral preoptic area (vlPOA) in sleep?
The vlPOA, a group of GABAnergic neurons located in the preoptic area of the hypothalamus, promotes sleep; it becomes active at night and inhibits activity in the RAS; if damaged, it can lead to insomnia and death.
***What is the role of orexin, histamine, and adenosine in sleep?
Histamine and orexin are stimulant neurotransmitters.
Histamine: Drugs that block histamine receptors (“Antihistamines”) cause drowsiness
Orexin: Damage to these neurons results in narcolepsy; contributes to “effortful wakefulness”
Adenosine is a hypnotic neurotransmitter:
-it builds up in the brain during the day and inhibits neurons
-caffeine is an adenosine antagonist
How can you improve memory retention during sleep?
If learning occurs in the presence of a specific odor (or other stimulus such as an auditory stimulus), memory retention will be greater if that same stimulus is presented during hippocampal activation in slow wave sleep
Slow wave sleep consolidates declarative memories
REM consolidates non-declarative memories
Describe circadian rhythms.
24 hour cycle in body temperature, activity, and hormone release.
- Body temp lowest in morning, highest at night
- Urination and bowel movements suppressed at night
- Cortisol levels highest in morning, lower at night
- Entrained mainly by light
***What is the difference between organizational effects and activational effects of hormones?
Organizational “developmental” effects of hormones: influence or control the development of an organism; permanent change in brain and sex organs result from hormonal exposure during development
Activational effects of hormones: temporary change (eg. functional) in sexual behavior due to hormonal exposure during adulthood
***Describe the development of primary sex organs and gender-specific brain
Gender based on sex chromosome (males = XY; female = XX)
Testes Determining Factor (or SRY) gene on Y chromosome causes testicular development in males
Nature produces female unless two hormones are released by testes:
1.) Mullerian-inhibiting hormone: Prevents development of female system (defeminization).
2.) Testosterone: Stimulates development of male (Wolffian) system (masculinization).
Hormonal cascade during puberty
Hypothalamus releases gonadotropin-releasing hormone (GnRH, which is controlled by kisspeptin)—->stimulates release of follicle-stimulating hormone (FSH) and lutenizing hormone (LH) from Pituitary—>stimulates estrogen (E) and progesterone (P) from ovaries or testosterone (T) from testes—>results in emergence of Secondary Sexual Characteristics
Describe activational effects of hormones on female sexual behavior
Estrogen and Progesterone
- dictate sexual drive in most female mammals(fertility is highest when E & P are high)
- In HUMAN females, initiation of sexual activity is greater during ovulation (when E levels are high)
***Further explain the following biological determinant of sexual orientation:
Activational effects of hormones (hormone levels during adulthood).
Females:
MAYBE an activational effect–T levels in lesbians are slightly higher than in straight women.
Males:
NO activational effect—T levels in gay and straight human males do not differ.
(However, gay rams do appear to have slightly lower T levels)
***Pair bonding, oxytocin, and vasopressin in voles
Prairie Voles have higher levels of receptors for the neuropeptides oxytocin and vasopressin than do Montane Voles. Prairie Voles form Monogamous mating pairs while Montane Voles mate in a non-monogamus manner.
Advantages to studying simpler organisms
- Mammalian brains are too big
- Most higher order forms of learning and memory are too complicated–>it is easier to study the simplest forms of learning and memory in the simplest nervous systems
- Roughly 16 million neurons in a mouse brain-100billion neurons in a human brain
How to produce behavioral habituation and sensitization in Aplysia
Habituating Aplysia:
Touch the siphon, the gill withdraws.
Keep touching the siphon, the gill withdrawal response habituates.
Habituation: a decline in an unconditioned response after repeated presentations of an unconditioned stimulus.
***Action potentials in sensory and motor neurons of control and habituated Aplysia
The same reaction occurs in the sensory neurons of the control and habituated Aplysia, however, the motor neuron in the habituated Aplysia doesn’t create an action potential after habituation???
***Describe the biochemical basis of habituation
Every tap on the siphon and action potential in the sensory neuron leads to less calcium entering the terminal—>which means that less neurotransmitter is released into the sensory-motor synapse.
***“Lessons” regarding habituation and learning in Aplysia
Transient learning is based on short-term chemical changes (e.g. changes in Ca+) in terminal buttons.
Memory is located in the terminal button of sensory neuron.
Habituation is a presynaptic phenomenon.
Memories are not housed in a separate set of “memory” neurons.
Memories tend to be “housed” within the neurons that are directly involved in the behavior or thought process.
Brains do not tend to have separate “hard drives” for data storage. W
***Action potentials in sensory and motor neurons of control and sensitized Aplysia
Before sensitization (Control), tactile stimulation to the siphon skin causes an action potential in the sensory neuron followed in time by an action potential in the motor neuron. After habituation (Sensitized), the sensory neuron maintains the same response to tactile stimulation but that the motor neuron response is now much larger. The recorded potentials are quantitatively larger in the motor neurons in the sensitized animals after taps to the siphon skin.
List the biochemical steps involved in short-term sensitization
- Initial tail shock causes interneuron to release serotonin.
- Serotonin binds to receptors on sensory neuron terminal.
- Receptor activates second messengers known as kinases.
- **Kinases bind to calcium channels.
- Few minutes later, tap to siphon produces action potential in sensory neuron.
- When action potential arrives at terminal, more calcium enters the terminal because the kinases hold channels open longer.
More calcium = more neurotransmitter released
List the biochemical steps involved in long-memory in Aplysia (kinases and genes)
Stronger tail shock causes even greater kinase levels in the siphon sensory neuron terminal. Kinases interact with DNA to promote gene transcription and synthesis of proteins, such as: growth factors (promote new membranes for more or bigger terminals) more kinases (keep calcium channels open even longer or perpetually keep kinase genes active).
A learning procedure;
when a stimulus that initially produces no particular response is followed several times by an unconditional stimulus that produces a defensive or appetitive response (the unconditional response), the first stimulus (now called a conditional stimulus) itself evokes the response (now called a conditional response)
** learning associations between stimuli
One event predicts another.
A bell predicts that food is coming.
Classical conditioning
A learning procedure whereby the effects of a particular behavior in a particular situation increase (reinforce) or decrease (punish) the probability of the behavior
- *One behavior predicts an outcome.
ex. A press on a bar yields a pellet of food.
Operant conditioning
The hypothesis that the cellular basis of learning involves strengthening of a synapse that is repeatedly active when the postsynaptic neuron fires.
Hebb rule
What is long-term potentiation (LTP) and how is it produced?
Long-term potentiation (LTP): a persistent increase in the responsiveness of a neuron to a specific synaptic input; this is caused by repeated high frequency activation of the specific input.
Pre-LTP:
PreSN--!--> PostSN--!-->
Stimulation:
PreSN--!!!!!--> PostSN--!!!!!-->
LTP:
PreSN--!--> PostSN--!!!!!-->
Hippocampus, NMDA, and Ca+2 are involvedWhat is some evidence that LTP is related to learning?
- It is long-lasting.
- There’s a practice effect - the more trials the more permanent it becomes.
- The increased response of the post-synaptic cell is like a memory - adaptive change to altered input (increased reactivity)
- It can be classically conditioned. (“neurons that fire together wire together” = HEBB RULE)
***Explain how weak synaptic connections are strengthened by activity at very strong synapses. (NMDA receptors)
At the strong synapse, a lot of glutamate is released.
Causes dendrites around the strong synapse to be depolarized.
At the weak synapse, at the same time, a little bit of glutamate is released (a subthreshold amount)
Little bit of glutamate binds to NMDA-type glutamate receptors that are voltage-dependent.
Little bit of glutamate and slight depolarization opens the NMDA receptor.
Calcium flows into dendrite adjacent to weak synapse.
***Explain how calcium may increase dendritic sensitivity to weak inputs.
NMDA receptors gate calcium.
Influx of calcium increases kinase activity in dendrite.
Kinases can activate other non-NMDA type glutamate receptors (AMPA)
Makes the dendrite more sensitive to input.
Kinases can enhance gene expression to change receptor number or dendritic shape.
Compare short-term vs. long-term memory
Short-term memories:
Appear to involve changes in neurotransmitter release or the sensitivity of neurotransmitter receptors (LOCAL changes).
Long-term memories:
May involve changes in gene expression (DISTRIBUTED changes) that create STRUCTURAL changes in neurons.
***What are causes of narcolepsy? (Ch.8 p. 194-196)
It is caused by a hereditary autoimmune disorder involving a gene found on chromosome 6
- people with narcolepsy are born with orexinergic neurons, but during adolescence, the immune system attacks these neurons, and the symptoms of narcolepsy begin
- Unknown environmental factors may be involved as well.
What are functions of slow wave sleep and REM sleep? (Ch.8 p. 197-201)
Functions of Slow-wave Sleep:
- lower the brain’s metabolism
- permit the brain to rest
- facilitates declarative learning
* seems to be the most important stage
Functions of REM Sleep:
- may promote brain development
- facilitates nondeclarative learning
* rebound effect makes up for lack of REM sleep
Explain the role of dopamine and basal ganglia regions in reinforcement (Ch.12 p. 313-317, Fig. 12.19)
Basal Ganglia:
The basal ganglia take over details of repetitive processes so we don’t have to think about what we are doing
Regions include- neostriatum (caudate nucleus and putamen): receive sensory info from all regions of cerebral cortex and from frontal lobes about movements that are planned or in progress—–> outputs of this structure are sent to globus pallidus: sends outputs to premotor and supplementary motor cortex (plans movements) and the primary motors cortex (executes those movements)
Important in instrumental conditioning
Dopamine:
Induces the synaptic changes responsible for instrumental conditioning by facilitating associative long-lasting long-term potentiation.
The cell bodies of the most important dopaminergic neurons are located in the ventral tegmental area their axons project to the nucleus accumbens, prefrontal cortex, limbic cortex, and hippocampus
*PKM-zeta is essential for the dopamine-dependent establishment of L-LTP
It’s pg 17
What is relational learning? (Ch.12 p.317-330)hm and hippocampus
H.M., a man who experienced anterograde amnesia due to a hippocampal lesion, Helped Milner and colleagues come up with the following conclusions about the role of the hippocampus:
- ) the hippocampus is not the location of long-term memories; nor is it necessary for the retrieval of long term memories (H.M wouldn’t have been able to remember events from early in his life, he wouldn’t have known how to talk, dress himself, etc.)
- ) the hippocampus is not the location of immediate (short-term) memories. (If it were, he would not have been able to carry on a conversation because he would not have remembered what the other person said long enough to think of a reply)
- ) the hippocampus IS involved in converting immediate memories into long term memories (H.M couldn’t make a permanent record of new information…due to lack of making permanent biochemical or structural changes in neurons
The hippocampal formation is also involved in spatial memory, even though it is non declarative (declarative memories–specifically episodic memories–are usually controlled by hippocampus). Relational learning is used for spatial navigation
What is slow-wave sleep?
a. The EEG shows synchronous firing. Muscle tone is moderate. Eye movements are not rapid. Genital activity is not seen
b. The EEG shows regular firing. Muscle tone is slack. Eye movements are rapid. Genital activity is seen in females but not in males.
c. The EEG shows asynchronous firing. Muscle tone is moderate. Eye movements are frequnetly rapid. Genital activity is not seen.
d. The EEG shows erratic firing. Muscle tone is taut. Eye movements are completely absent. Genital activity is seen in males but not in females.
a. The EEG shows synchronous firing. Muscle tone is moderate. Eye movements are not rapid. Genital activity is not seen
How long does it take for a typical person to experience REM sleep for the first time in an evening?
a. about 90 minutes
b. about 45 minutes
c. about 30 minutes
d. about 3 hours
a. about 90 minutes
What is the significance of desynchrony in EEG recordings of sleep?
a. Desynchrony shows a person is responsive and awake
b. Desynchrony usually reflects less active thinking and less awareness.
c. Desynchrony shows that a person is asleep.
d. Desynchrony typically shows that a variety of neural circuits are highly active and a person is actively thinking.
d. Desynchrony typically shows that a variety of neural circuits are highly active and a person is actively thinking.
How might slow-wave sleep be helpful to people?
During the down state of each oscillation of slow-wave sleep, enormous numbers of neurons are inhibited, allowing them to rest and be replenished in a meaningful way
Which of the following identifies the lowest frequency form of sleep?
a. Stage 2 sleep
b. Theta activity
c. Stage 4 sleep
d. REM sleep
c. Stage 4 sleep?
A technician is monitoring the EEG records for several sleep subjects in a laboratory. Which subject is likely to be in the transition stage between sleeping and waking?
a. A subject that has an EEG frequency of 3 Hz and considerable indication of sleep spindles or K complexes
b. A subject that has an EEG frequency of 14 Hz and no indication of sleep spindles or K complexes
c. A subject that has an EEG frequency of 5 Hz and no indication of sleep spindles or K complexes
d. A subject that has an EEG frequency of less than 1 Hz and no indication of beta activity
c. A subject that has an EEG frequency of 5 Hz and no indication of sleep spindles or K complexes
A researcher looks at EEG sleep records from a variety of different individuals. To find individuals who are likely to be intelligent, what should the researcher look for in EEG patterns?
a. The researcher should look for a high level of REM sleep
b. The researcher should look for a high level of K complexes
c. The researcher should look for a high level of sleep spindles
d. The researcher should look for a high level of slow-wave sleep
c. The researcher should look for a high level of sleep spindles
* Increased numbers of sleep spindles are correlated with increased scores on intelligence tests.
Which of the following provides the strongest evidence that sleep is necessary for good health and survival?
a. Human beings that suffer sleep deprivation are also prone to starvation
b. Though human beings can go without food for months, a sleep deprived person will be unable to resist sleep for more than a few days.
c. Organisms with total insomnia due to damage in the preoptic area or individuals with fatal familial insomnia cannot survive for very long without sleep.
d. All vertebrates, including fish, reptiles, and amphibians, go through a sleep period of quiescence every few hours.
c. Organisms with total insomnia due to damage in the preoptic area or individuals with fatal familial insomnia cannot survive for very long without sleep.
What comprises the ticking in a biological clock?
a. breakdown of a neurotransmitter in a synapse
b. production of a nucleic acid
c. production and breakdown of a protein
d. the number of times an enzyme uses its active site
c. production and breakdown of a protein
Where is the biological clock located?
a. in the suprachiasmic nuclei of the hypothalamus
b. in the prefrontal cortex
c. in the preoptic area
d. in the ventral portion of the right side of the primary visual cortex
a. in the suprachiasmic nuclei of the hypothalamus
Why are the lives of most people with even the most severe sleep apnea rarely threatened?
Without any oxygen being taken in, the blood of people with sleep apnea accumulates carbon dioxide, which triggers chemoreceptors that in turn stimulate gasping behavior, causing the person to wake up.
Which of the following is most likely to produce cataplexy?
a. being forced to stay awake by circumstances
b. eating rich food
c. a fit of laughter
d. needing to sit through a dull movie
c. a fit of laughter
What is the relationship between adenosine and glycogen?
During wakefulness, glycogen in astrocytes is consumed by active brain neurons. Prolonged wakefulness causes a decrease in the level of glycogen in the brain. A fall in the level of glycogen causes an increase in the level of adenosine.
A research scientist is able to measure activity levels for acetylcholine for a volunteer subject who had normal sleep patterns in the brain’s arousal areas. The scientist finds high levels of ACh activity not only during the day, but also in the middle of the night. The scientist asked the volunteer how well he had slept during the night, and the volunteer claimed he had slept normally with no interruptions. What should the scientist conclude?
High levels of acetylcholine should be expected during active moments of wakefulness and also during REM sleep, so the subject was asleep during the time that ACh levels were high
The Circadian rhythm is a 24 hour cycle in body temperature, activity, and hormone release. Describe differences in each of these categories during the daytime and nighttime.
- Body temp is lowest in the morning, and highest at night
- Urination and bowel movements are suppressed at night
- Cortisol levels are highest in the morning and lower at night
