Midterm review (Bio psych)

Name the 2 debates that have shaped the field of behavioral neuroscience.

1. Mind-body problem

2. Nature vs nurture debate

Describe the mind-body problem.

The issue of what the mind is and what its relationship is to the brain.

What the current theory that neuroscientists work from regarding the mind-body problem?

- The mind and brain are the same
- Conscious experience is created by the brain.

Describe the nature vs. nurture debate

The debate over whether traits are shaped more by genetics or by life experiences.

What is the current view regarding the nature vs. nurture debate?

Genes create a predisposition for traits, while the environment influences how they are expressed.

How many chromosomes do human body cells have?

46 chromosomes (23 pairs)

What two pieces of evidence support the idea that the mind and brain are the same?

1. Role of electricity
2. Localization of function

Name 3 research techniques used to determine the heritability of a trait.

1. Family studies
2. Adoption studies
3. Twin studies

Describe the limitations of using family studies to determine the heritability of a trait?

Family members often share the same environment, making it difficult to separate genetic and environmental influences.

Describe the limitations of using adoption studies to determine the heritability of a trait?

- Adoptive parents often share similar traits (e.g., socioeconomic status, personality).

- Adoption agencies may place children in similar environments to those of their biological parents.

Why is color-blindness more common in genetic males?

Color blindness is an X-linked recessive trait. Males (XY) have only one X chromosome, so if they inherit the gene, they will express the trait since there's no second X to compensate.

Who is Phineas Gage?

Survived a frontal lobe injury from an iron rod; his personality changed, but intelligence, memory, and movement remained intact.

What is the takeaway from the case of Phineas Gage?

Localization of function: different brain areas control different functions

What is Broca's area?

Brain area involved in speech production

What is Broca's aphasia?

Brain disorder that affects speech production

What do genes do?

Encode proteins

What do proteins do?

- Build cells, neurotransmitters, receptors, enzymes

- Regulate gene expression

Monozygotic (identical)

Twins that develop from one egg and share 100% of genes

Dizygotic (fraternal)

Twins that develop from two separate eggs and share 50% of genes

The proportion of twin pairs where both twins share a given trait or disorder

Concordance

The percentage of the variation among individuals in a characteristic that can be attributed to heredity

Heritability

Monozygotic twins: .62
Dizygotic twins: .30

State whether this trait appears to be determined by genetics, the environment, or a combination of both.

both

Monozygotic twins: 1.0
Dizygotic twins: .50

State whether this trait appears to be determined by genetics, the environment, or a combination of both.

genetics

Monozygotic twins: .80
Dizygotic twins: .80

State whether this trait appears to be determined by genetics, the environment, or a combination of both.

environment

Depolarization

increase in voltage

Hyperpolarization

decrease in voltage beyond resting potential

Repolarization

decrease in voltage

The biological unit that directs cellular processes and transmits inherited traits.

Gene

XX

female

XY

male

Autosomes

Non-sex chromosome

Traits: Influenced by multiple genes rather than a single gene, often interacting with environmental
factors.

• Most psychological traits are determined by multiple genes.

Polygenic

Transmit and process information.

Neurons

One branch extends from the soma.

Unipolar neurons

One dendrite and one axon.

Bipolar neurons

What type of neuron is primarily associated with vision and hearing?

Bipolar

What is the major function of bipolar cells?

Vison & hearing

What is the major function of unipolar cells?

Touch

Most common types in the nervous system.

Multipolar neurons

An extension from a neuron’s cell body that carries information to other locations.

Axon

What is the name of the disease that damages the myelin?

Multiple Sclerosis (MS)

Which of the following is carried by an autosomal dominant gene?

Huntington’s disease

• Ion gates open in response to specific stimuli:

  • Voltage-gated channels— open in response to changes in electrical charge.

  • Ligand-gated channels— open when a ligand binds to a receptor.

• Ligand: Any molecule that binds to a receptor with some selectivity.

  • In this class, “ligand” refers primarily to neurotransmitters

Ion Movement Through Channels

• Diffusion: Movement of ions from high to low concentration (does not require energy).

  • Example: A packed elevator—when doors open, people rush out to spread out.

• Electrostatic pressure: Like charges repel; opposite charges attract.

Forces Driving Ion Movement

Resting potential of a neuron

-70 mV

A partial depolarization of the dendrites and cell body, which makes the neuron more likely to fire.

Excitatory postsynaptic potential (EPSP)

A hyperpolarization of the dendrites and cell body, which makes a neuron less likely to fire.

Inhibitory postsynaptic potential (IPSP)

The summing of all of the EPSPs & IPSPs on a neuron

neural integration

The area in which a neuron passes chemical signals to another neuron, muscle, or organ.

Synapse

An all-or-none electrical signal of a neuronal membrane that contains an abrupt voltage depolarization and return to resting potential; allows the neuron to communicate over long distances.

Action potential

Axon hillock

Where does an action potential originate?

First step of an action potential

Na+ channels open

Second step of an action potential

Na+ enters

Third step of an action potential

Membrane depolarizes

Fourth step of an action potential

K+ channels open

Fifth step of an action potential

K+ leaves

Sixth steps of an action potential

Membrane hyperpolarizes

Which of the following causes the membrane to depolarize during an action potential?

Na+ entering the cell

Which of the following causes the membrane to hyperpolarize during an action potential?

K+ leaving the cell

What 2 things cause Na+ ions to move hrough the membrane once the channels open?

Diffusion & Electrostatic pressure

Large protein molecules that move sodium ions through the neuron membrane to the outside and potassium ions back inside, helping maintain the resting potential.

Sodium-potassium pump

Which of the following is true of the sodium-potassium pump?

It pumps Na+ out of the cell and K+ inside the cell

The flow of electricity down the axon in which action potentials jump from one node of Ranvier to the next.

Saltatory conduction

Where is the Na+ cell primarily located when the neuron is at resting potential?

outside

Where is the CI- cell primarily located when the neuron is at resting potential?

outside

Where is the K+ cell primarily located when the neuron is at resting potential?

inside

Where is the Ca+ cell primarily located when the neuron is at resting potential?

outside

Support and protect neurons.

Glia

Glial cells that provide immune protection in the central nervous system by acting as macrophages.

Microglia

A type of glial cell that forms the myelin covering of neurons in the brain and spinal cord.

Oligodendrocyte

A type of glial cell that forms the myelin covering on neurons outside the brain and spinal cord.

Schwann cell

type of glia:
- Named for their star-like shape ("astro-").
- Form dura mater (scar tissue)—prevents neurons from forming new connections.
- Critical to learning (still being studied).

• Which glia cell provides structural support to neurons and helps maintain the extracurricular environment by removing excess neurotransmitters?

Astrocytes

Where are Purkinje cells located?

Cerebellum

An infection of the minges (the coverings of the brain & spinal cord)

Meningitis

An attack on the brain involving a loss of blood flow to a particular brain area

Stroke

Two types of strokes

Ischemic stroke & Hemorrhagic stroke

What does FAST stand for?

Face, Arms, Speech, Time

Chemical messengers that transmit signals.

Neurotransmitters

First step to NT release

CA++ channels open

Second step to NT release

Ca++ enter

Third step to NT release

Fusions pores open

Fourth step to NT release

NTs diffuse

What happens when neurotransmitters bind to recepters

Ligand-gated ion channels open

Drugs that enhance or mimic the effects of a neurotransmitter

Agonists

Drugs that block or diminish the effects of a neurotransmitter

Antagonists

What neurotransmitter is always inhibitory?

GABA (inh)

Neurotransmitter that acts as a transmitter at the muscles; in the brain, it is involved in learning, etc..

Acetycholine

Neurotransmitter involved in mood, sleep and arousal, aggression & depression

Serotonin

Neurotransmitter that contributes to movement control and promotes reinforcing effects of food, sex, and abused drugs. Dysregulation is involved in schizophrenia and Parkinson’s disease.

Dopamine

functions as a neurotransmitter in the brain to increase arousal and attentiveness to events in the environment. Diminished transmission of this neurotransmitter is involved in depression.

Norepinephrine

A stress hormone related to norepinephrine; plays a minor role as a neurotransmitter in the brain.

Epinephrine

The principal excitatory neurotransmitter in the brain and spinal cord. Vitally involved in learning

Glutamate

The predominant inhibitory neurotransmitter. Its receptors respond to alcohol and the class of tranquilizers called benzodiazepines.

GABA

Inhibitory transmitter in the spinal cord and lower brain. The poison strychnine causes convulsions and death by affecting the activity of this neurotransmitter.

Glycine

Substances produced in the body that function both as neurotransmitters and as hormones and that act on opioid receptors in many parts of the nervous system.

Endorphins

Ach Agonists

Nicotine, Physostigmine, Black Widow Spider Venom & Alzheimer’s treatments

Ach Antagonists

Botox and Curare & Atropine

Dopamine Agonist

L-dopa

Dopamine Antagonist

Antipsychotics