final brain and behavior exam .2

What is the usual sleep pattern for people with depression?

 Early onset of REM and early awakening

What type of depression shows the highest heritability?

 Early-onset depression

How do SSRIs differ from tricyclic antidepressants?

 SSRIs act on just one neurotransmitter.

What do MAOIs do?

 They decrease the breakdown of several neurotransmitters.

What is the disadvantage of using St. John’s wort as an antidepressant?

 It decreases the effectiveness of other drugs.

When someone begins taking an SSRI or a tricyclic antidepressant, how soon are behavioral benefits likely to emerge?

weeks later

Besides increasing neurotransmitter levels, what do typical antidepressant drugs have in common?

 They facilitate neurotrophins.

How does the effectiveness of psychotherapy for depression compare to that of antidepressant drugs?

They are about equally effective, and they have similar effects on the brain.

What is the recommended treatment for seasonal affective disorder?

 Very bright lights every morning

Which of these is a “positive” symptom of schizophrenia?

Delusions

The main evidence for heritability of schizophrenia comes from what type of research?

 Comparisons of twins

According to the two-hit hypothesis, what causes schizophrenia?

 A genetic predisposition plus an environmental impact

Which of these is a likely explanation for the season-of-birth effect?

 Viral epidemics are common in the fall.

Most people with schizophrenia have behavioral anomalies similar to those of people with damage to which brain area?

 Prefrontal cortex

Which of the following observations supports the dopamine hypothesis of schizophrenia?

 Abuse of amphetamine or similar drugs can cause hallucinations and delusions.

Which of these is a common side effect of first-generation antipsychotic drugs?

 Tardive dyskinesia

Antipsychotic drugs are most effective at relieving which symptoms of schizophrenia?

the positive symptoms

According to the glutamate hypothesis, what is the chemical origin of schizophrenia?

 Reduced activity at NMDA receptors in the hippocampus

Why can you move your eye muscles more precisely than your biceps?

 

The eye muscles have a higher ratio of axons to muscle fibers.

How can you move an arm or leg back and forth?

 

Alternate between exciting your flexor and extensor muscles.

You rely on your slow-twitch muscle fibers for which of the following?

 

Slowly walking and talking

What do proprioceptors detect?

Position or movement of a body part

What does a Golgi tendon organ do?

 It detects the tension that results from a muscle contraction.

Where is the primary motor cortex?

 In the frontal cortex, just anterior to the central sulcus

How do the actions of sneezing differ from those of talking and writing?

 They do not depend on the cerebral cortex.

When is the supplementary motor cortex most likely to be active?

During a second or more before a voluntary movement

What does the ant saccade task measure?

 Ability to inhibit an impulse

How do the functions of the lateral and medial corticospinal tracts differ?

The lateral corticospinal tract crosses to the opposite side of the spinal cord and controls precise movements of the extremities, such as hands, fingers, and feet. The medial corticospinal tract controls trunk muscles for bilateral movements such as standing, bending, turning, and walking.

Which of the following produces symptoms that resemble damage to the cerebellum?

Alcohol intoxication

How are the parallel fibers of the cerebellum arranged relative to each other and to the Purkinje cells?

They are parallel to one another and perpendicular to the planes of the Purkinje cells.

What type of learning depends on the basal ganglia?

Learning new habits

According to Libet’s study, what is the order of events in a voluntary movement?

Activity begins in the premotor cortex, a bit later, people are aware of forming an intention, and finally the movement starts

Parkinson’s disease results from loss of axons that release which transmitter?

dopamine

Parkinson’s disease results from loss of axons that originate in which structure?

 Substantia nigra

What type of gene causes Huntington’s disease?

An autosomal dominant gene

Examination of someone’s chromosomes can reveal not only whether the person will get Huntington’s disease, but also what else?

The probable age of onset

What is the main zeitgeber for the human circadian rhythm?

Light

Which brain area generates the circadian rhythm?

 The suprachiasmatic nucleus

If you want to get to sleep on time, what should you avoid?

short-wavelength light, late-evening exposure

After the proteins TIM and PER reach a high level during the day, what causes their level to drop at night?

 High levels of the proteins inhibit the genes that produce these proteins.

Which of these releases melatonin?

 

Pineal gland

A polysomnograph measures EEG and what else?

eye movement

Sleep spindles are associated with which of the following?

memory consolidation

Why is REM sleep also known as paradoxical sleep?

 

It is deep sleep in some ways and light in others.

Why are postural muscles least active during REM sleep?

 

Inhibition from the pons and medulla

When (if at all) is REM most frequent?

 In the later part of the night’s sleep

What does the neurotransmitter histamine do?

 

It increases arousal and alertness.

When is the locus coeruleus most active?

 

During memorable or stressful events

What would happen to the sleep–wake schedule of someone who lacked orexin?

 

Alternation between brief periods of waking and sleeping

The PGO in PGO waves is an abbreviation for what?

 

Pons-geniculate-occipital

Why are we unconscious during sleep?

 

GABA inhibits synaptic spread of information.

Sometimes people cannot move their postural muscles immediately after awakening. Why?

 

Part of the brain is still asleep.

Which of the following often triggers an attack of cataplexy in a person with narcolepsy?

 

Strong emotions

According to the neurocognitive model, why do dreams sometimes make an incoherent or illogical story?

 

Low activity in the prefrontal cortex means poor memory for what just happened.

How many dendrites and axons does a neuron have?

Any number of dendrites, and no more than one axon

What do dendritic spines do?

 They increase the area available for synapses.

What does a myelin sheath do?

it insulates axons

What is the difference between afferent and efferent axons?

 Afferent axons carry information in, and efferent axons carry it out.

What type of cell synchronizes the activity of a related group of axons?

Astrocytes

Why are brain cancers so difficult to treat?

 Chemotherapy drugs do not cross the blood–brain barrier.

When a neuron is at rest, how does the electrical charge compare for the inside and outside of the membrane?

 The inside has a negative charge.

What does the sodium–potassium pump do?

 It pumps sodium out and potassium in.

When the neuron membrane is at rest, what forces are acting on sodium ions?

 Both the electrical gradient and the concentration gradient tend to pull them into the cell.

When the membrane is at rest, why don’t sodium ions enter the cell?

 The sodium gates are closed.

What does depolarization of a neuron membrane mean?

 Decreasing its negative charge

When a neuron membrane is depolarized enough to reach its threshold, what happens?

 

The membrane opens its sodium channels.

Because of the all-or-none law of the action potential, what is an axon unable to change?

 The size of its action potentials

After the peak of the action potential, what enables the membrane to get back to its resting potential?

 

The sodium channels close but the potassium channels remain open.

What is the absolute refractory period of an axon?

 The time when it is incapable of producing an action potential

How is an action potential conducted in a myelinated axon?

 By a relay from one node of Ranvier to the next

What conclusion followed from the discoveries of both Sherrington and Cajal?

 Neurons are separate from one another.

What does the presynaptic neuron do?

 It releases chemicals into the synapse.

Rapidly repeating a mild stimulus produces a response that a single stimulus does not. What does this observation demonstrate?

 Temporal summation

How does a graded potential differ from an action potential?

 A graded potential can be either excitatory or inhibitory.

Does an IPSP cause an action potential?

 No, it reduces the probability of an action potential.

Which statement accurately describes depolarization and hyperpolarization?

 Depolarization produces excitation, and hyperpolarization produces inhibition.

What do both an EPSP and an IPSP do?

 Alter the frequency of a spontaneous firing rate

At which type of synapses does input from an axon hyperpolarize the postsynaptic cell, moving the cell’s charge farther from the threshold and decreasing the probability of an action potential?

 Inhibitory synapses

Otto Loewi stimulated one frog’s heart to increase its rate, and then transferred some fluid from that heart onto a second frog’s heart. What conclusion emerged from the results?

 Synaptic transmission is (at least sometimes) chemical.

What do the vesicles in a neuron do?

 They store neurotransmitters.

What is exocytosis?

 Release of neurotransmitter

Which of the following enables synaptic transmission to be as fast as it is?

 The synaptic cleft is very narrow.

What type of effect occurs at an ionotropic synapse?

 Fast and brief

How does a metabotropic synaptic receptor exert its effects?

 It activates a second messenger inside the neuron.

What is at the center of an excitatory acetylcholine receptor?

 A sodium channel

Under what condition are ionotropic receptors more suitable than metabotropic receptors?

 When precise timing is important

What is the function of the enzyme acetylcholinesterase?

 It breaks acetylcholine down into components for recycling.

When a person stands in the normal position, where is the dorsal part of the brain?

on the top

If two structures are both on the left side of the body, what is their relationship to each other?

Ipsilateral

What is a gyrus?

 A protuberance on the surface of the brain

Someone with spinal cord damage has lost muscle control for one part of the body. Where is the damage?

 The ventral roots of the spinal cord

For both the spinal cord and the brain, how does gray matter differ from white matter?

 Gray matter has cell bodies, and white matter has just axons.

Which system prepares the body for “rest and digest” activities?

 The parasympathetic nervous system

The hindbrain consists of what?

 The medulla, pons, and cerebellum

How many pairs of cranial nerves do humans have?

12

Which sensory system sends input directly to the cerebral cortex, bypassing the thalamus?

Olfaction

Damage to which structure is most likely to impair feeding, drinking, sexual behavior, and temperature regulation?

 Hypothalamus

How does the organization of the brain differ among mammalian species?

 They differ in size, but not much else.

Someone who suddenly loses the ability to identify objects by feeling them has probably suffered damage to what area of the cerebral cortex?

 Parietal lobe

Suppose a person that has experienced brain-damage seems normal in many ways but often makes impulsive decisions without considering all the pros and cons. Where would you expect to find the brain damage?

 Prefrontal cortex