Private PSych

Skeletal muscle movement

Acelycholine

A neuron's membrane is selectively permeable. This means that it:

Allows some molecules to pass through it, but blocks others

One thing the All-Or-None Law states is that:

An action potential will always travel at the same speed and strength no matter how strong the stimulation on the neuron's dendrites and soma

We can say that the neural signal has successfully been transmitted between two neurons when a neurotransmitter:

Binds to its receptor on the postsynaptic membrane resulting in graded potentials

At the axon terminal, the release of neurotransmitters by exocytosis is triggered by:

Calcium ions entering the presynaptic membrane during depolarization

Reward (euphoric high) & reinforcement

Dopamine

The absolute refractory period for a neuron is the time:

During which a second action potential cannot be triggered, no matter how strong the stimulus

Stimulant energy - emphasis on physical energy

Epinephrine

With the naked eye, it is easy to tell the difference between a small amount of brain tissue in a human compared to a small amount of brain tissue in a monkey.

False

Our brains cannot manufacture any new brain cells (neurons) in old age.

False Up until a few years ago (yesterday in science!), researchers believed that you developed all of the neurons you'd need for a lifetime by the age of 1. More recent research with older adults shows that at least one area of the brain - the hippocampus (important for forming new memories and spatial memory) - can develop brand new neurons out of stem cells even in much older adults. These new neurons are used to support new behaviors that are learned, such as learning a complex city "map" by memory in order to become a London taxi driver. This is brain plasticity at its finest.

Research has shown that humans only use 10% of their brain capacity.

False This is a popular theme in science fiction but it is a myth. In truth, we use 100% of our brain - we simply do not understand the exact functions of every structure or group of brain cells.

At an inhibitory synapse on a dendrite, the binding of the neurotransmitter to its receptor causes:

Hyperpolarization of the postsynaptic membrane

Vesicles are located _________ and their function is to _________

In the presynaptic terminals, store neurotransmitters

If an excitatory graded potential synapses directly onto the axon hillock:

It is possible that this single graded potential can fire an action potential

Which of the following cells is NOT an example of glia?

Motor neurons

At a typical synapse, the chemically-gated channels that open when a neurotransmitter binds to its receptor are found here:

On the postsynaptic membrane

Voltage-gated sodium channels are found at all of the following locations on a neuron EXCEPT:

On unmyelinated axons

One function of the myelin sheath is to

Provide insulation to help keep the action potential moving quickly and without losing speed

Stable mood & sense of wellbeing

Serotonin

During the depolarization phase of an action potential, which of the following happens first?

Sodium channels open and Na+ ions flow into the cell

Alerts you that you are in pain

Substance P

During the depolarization phase of an action potential, what electrical change takes place?

The inside of the membrane becomes more positive compared to the outside

Which of the following describes a typical neuron at rest:

The potassium concentration is lower outside the cell than inside

This active transport system is one necessary way of keeping the concentration of sodium and potassium ions balanced (for polarization) on either side of the selectively-permeable membrane during RMP

The sodium-potassium pump

If you electrically shock a cat's brain in a certain place, it can cause the animal to cower in terror in the presence of a small mouse.

True The amygdala, a structure within the limbic system of the brain, is responsible for aggression and fear responses in animals. If you electrically shock the amygdala in one spot in a cat, for example, you'll get "attack-mode." In another spot within the amygdala, you'll get a cowering, fear response.

Some people can speak but are unable to read or understand language.

True In the brain, we see a dissociation (splitting off) of function based on the brain structures that "control" that function. If you look at the image of the left hemisphere of a human brain, you will see that there are two major brain structures related to language. Broca's area is important for speech. If you damage it, you will have great difficulty producing speech, but can understand language. On the other hand, Wernicke's area is important for understand/comprehending language. If you damage it, you cannot understand any language, but will still be able to speak in full, grammatically-correct sentences. This is a terrific example of the type of brain structure-function relationships we will talk about throughout the semester.

Some researchers believe that alcoholism, binge eating, and other addictive disorders may be inherited (genetic), leading some individuals to need an abnormally high amount of a substance or other stimulus to feel pleasure.

True Similar to the answer to #4, this phenomenon is theorized to be related to the hypothalamus reward centers within the limbic system, including the nucleus accumbens. Through plasticity - the brain's ability to reorganize based on experiences, repeated behavior, drug use, etc. - the theory of "reward deficiency syndrome" is believed to have a hereditary/genetic component to it. Therefore, one's children can be "set up" to need "more" of something to feel rewarded.

Both animals and humans seem to have reward/pleasure centers in the brain.

True The dopamine reward-reinforcement areas of the brain - most notably the nucleus accumbens that we'll study in Ch. 2 - are related to the euphoric, pleasurable "highs" we experience, such as orgasm and certain drug highs (for example, heroin). Rewards are important for certain behaviors in humans and other mammals so that we are more likely to perform those behaviors again (definition of reinforcement). Obviously, sexual behavior needs to be rewarding so we procreate. Unfortunately, we have found maladaptive ways to reward ourselves and reinforce damaging behavior, such as substance abuse.

If a blind person uses one finger to read Braille, the brain area that "controls" that finger's function becomes larger to support the new experience.

True This is another example of brain plasticity - the brain's ability to reorganize based on experience, injury, or drug use. In this case, if you learn a new motor skill such as using a particular finger to read Braille, the brain area that supports this finger's function will reorganize, "borrowing" neurons from neighboring areas. In this way, the brain will sometimes give you what you need if you wish to learn new things.

Some people have had the two hemispheres (halves) of their brains surgically split and you probably wouldn't know it if you observed or talked to the person.

True We'll study about this phenomenon in the chapter on brain hemisphere differences and the corpus callosum. A split-brain surgery is performed to cut the connection between the two hemispheres in individuals diagnosed with a particular and severe form of epilepsy. During the weeks and months after the surgery, the individual learns to adjust behaviorally, such that most people would not be able to tell that the person's two hemispheres are no longer connected. This is a person who truly has two brains, functioning separately from one another! The surgery is highly effective in stopping the seizure activity, too.

Which of the following area(s) of a neuron typically receive(s) input (AKA chemical neural signal) from other neurons?

Cell body Dendrite

Helps control pain and stress

Enkephalins

Brain's main inhibitory NT

GABA

The brain's main excitatory NT

Glutamate

Allergies

Histamine

Stimulant energy - emphasis on confidence & wellbeing

Norepinephrine

The term "saltatory conduction" refers to the:

Propagation of the electrical neural signal down a long, myelinated axon

A neuron received EPSPs simultaneously at several different locations on its dendrites and soma. When those EPSPs travel to the axon hillock, they are added together through a process known as:

Spatial summation

Which of the following is/are true of postsynaptic potentials (PSPs) in general?

They can sum together by spatial and/or temporal summation

The human brain produces its own natural opiates, chemicals that regulate pain and make you feel good (mood).

True