Test 1 Drugs and the Brain

What’s the difference (in terms of drug effects) between psychoactive and non-psychoactive drugs?

Psychoactive drugs can change our feelings, thoughts, or make us feel different, like being happy or sleepy. Non-psychoactive drugs just help our bodies without changing how we feel.

What’s the difference between drug action and a drug effect? Give an example of each.

Drug action is what a drug does inside our bodies, like fighting germs. A drug effect is how it makes us feel better, like stopping a headache. For example, aspirin fights pain (drug action), and it makes your headache go away (drug effect).

What sort of molecules might be classified as a “drug”?

Molecules that can help treat or cure illnesses, or change the body chemically from normality

1. What term refers to the general study of how drugs can affect biological processes? 2. What more specific term refers to the study of drugs’ effects on thinking, feeling, and behaving?

1. "pharmacology."
   2. "psychopharmacology."

What structure must a drug cross to be considered a psychoactive drug?

To be a psychoactive drug, it needs to sneak past a special gate called the "blood-brain barrier." It's like a secret entrance to our brain.

What’s the difference between a therapeutic effect and a side effect?

A therapeutic effect is like the main job of a medicine, such as curing an illness. A side effect is like an extra thing it does, which may not always be good, like making you feel dizzy.

In what way is the placebo effect an example of a nonspecific drug effect?

The placebo effect happens when our brain thinks a fake medicine is real and makes us feel better. It's like magic because our brain can make us feel better even without real medicine.

Are neurotransmitters endogenous or exogenous? What about drugs?

Neurotransmitters are inside our bodies, so they are endogenous. Drugs are made outside our bodies, so they are exogenous, like toys we bring from outside to play with.

Why might one want to conduct a blind or double-blind experiment?

In a blind or double-blind experiment, we hide some information to be fair. It's like playing hide and seek to find out if a medicine works without knowing who's taking the real medicine and who's not.

What do we call the study of how drug molecules move through the body?

We call it "pharmacokinetics," which is like studying how tiny cars move on roads inside our bodies.

What are some factors that will affect a drug’s bioavailability?

Things like how we take the medicine, what we ate, or how fast our body cleans it up can change how much of the medicine actually works.

Be able to give one advantage and disadvantage of the main routes of administration we discussed.

Taking medicine by mouth (like syrup) is easy (advantage), but it takes time to work because it has to go through your tummy (disadvantage).

What role does diffusion play in drug absorption?

Diffusion is like spreading butter on bread. It helps the medicine move from where we put it to where it's needed in our body.

What body system is responsible for drug distribution?

Our blood and heart are like delivery trucks that take medicine everywhere in our body.

What kinds of things can and cannot diffuse across a phospholipid membrane?

Tiny things like water can sneak through the membrane, but big things like toys can't get in.

How does pH affect drug absorption?

pH is like a scale of sour and sweet. Some medicines like sour places, and some like sweet places. So, pH can change how medicine moves in our body.

Describe the structure and function of the blood-brain barrier.

The blood-brain barrier is like a wall around your brain. It stops some things from getting in, like big monsters, so your brain stays safe.

What’s the difference between drug binding at the site of drug action and depot binding? What effects can depot binding have on bioavailability?

When a drug binds where it's supposed to, it makes the neuron fire. But sometimes, depot binding makes it not, and that can make it work slower or faster.

What kinds of processes are involved in drug clearance?

Drug clearance is like cleaning up toys after playing. Our body uses different processes to get rid of the medicine, like breaking it down or peeing it out.

What do we call the study of the mechanisms of drug action?

pharmacodynamics

Describe the effects of the efficacy and affinity of a ligand for a given receptor. How do those ideas help us understand the mechanism of a receptor agonist and a receptor antagonist?

Efficacy is like how strong a superhero is, and affinity is like how much a superhero likes their job. An agonist is a superhero that helps a lot, and an antagonist is like a superhero who blocks the bad guys.

Understand the range of effects a drug can have, from agonist vs. inverse agonist and in between.

Some medicines help a lot (agonist), some don't do much (neutral), and some make things worse (inverse agonist).

In what ways might a cell change its receptors as a result of changes in levels of a drug (or neurotransmitter)?

Cells can change their shapes to catch more or fewer of the things they need, like adjusting their hands to catch different types of balls.

What are the different subtypes of a given type of receptor?

Subtypes are like different models of cars from the same brand. They do similar things but have some unique features.

How do we characterize the relationship between dose and drug effect in terms of the dose-response curve?

t's like how much candy you eat affects how happy you feel. The more candy, the happier (or sicker) you get.

What position along the dose-response curve indicates a drug that has greater or lesser potency?

If a little bit of medicine makes you feel better, it's more potent. If you need a lot for the same effect, it's less potent.

How can we use the dose at which 50% of people experience a toxic effect to calculate a drug’s therapeutic index? Is a larger number good or bad?

We use the dose where half of the people get sick to figure out if a medicine is safe. A larger number is good because it means the medicine is safer

Explain the concepts related to chronic drug use (tolerance, cross-tolerance, etc.).

1. Tolerance: Your body getting used to a drug

2. Cross-Tolerance: Getting used to one drug makes you used to another one

3. Dependence: Sometimes, if you use a drug a lot, your body gets used to having it around.

4. Withdrawal: When you stop using a drug your body is dependent on, it can act like a little protest.

5. Addiction: Addiction is when you can't stop using a drug even if it's causing problems in your life.

Pharmacology

the branch of biology and medicine that deals with the study of drugs, effects on biological systems and their interactions with living organisms

Psychopharmacology

a subfield of pharmacology ; focuses on the study of drugs that affect mood, behavior, and cognition, including their mechanisms of action and therapeutic uses.

Drug Action

the specific biochemical interactions between a drug and its target in the body. It describes how a drug produces its effects at the molecular level.

Drug Effects

the observable and measurable changes or responses that occur in the body or mind as a result of drug action. These effects can be therapeutic or adverse.

Psychoactive Drugs

drugs that effect mood, behavior, and brain functions

Therapeutic Effects:

the intended and outcomes of drug treatment.

Side Effects

unintended and often undesirable effects of a drug that occur in addition to its therapeutic effects.

Specific Drug Effects

the direct and predictable outcomes of a drug's interaction with its target in the body. These effects are responsible for the therapeutic benefits of the drug.

Nonspecific Drug Effects

drug effects influenced by factors like expectation and context.

Placebo

inert substance (such as a sugar pill) or treatment that has no pharmacological effect but may produce a perceived improvement in a patient's condition because they believe it will.

Endogenous

substances or processes that originate from within the body itself, rather than being introduced externally.

Exogenous

substances or processes that come from outside the body or are introduced externally.

Blinding

research technique where participants or researchers are unaware of certain aspects of a study, such as whether a participant is receiving a real drug or a placebo.

Double-Blind Experiment

study design in which both participants and researchers are unaware of who is receiving the active drug and who is receiving a placebo. It helps reduce bias in research.

Pharmacokinetics.

study of how the body processes drugs, including their absorption, distribution, metabolism, and elimination.

Bioavailability

the proportion of a drug that enters the bloodstream when introduced into the body, and it is available for its intended action.

Dose

specific quantity or amount of a drug that is administered to a patient at a given time.

Routes of Administration

various methods that drugs can be introduced into the body. Ex: Oral, Intravenous, Subcutaneous

Absorption

process by which a drug enters the bloodstream from the site of administration, typically through the digestive tract or the bloodstream.

Distribution

how a drug is transported throughout the body, including its movement into various tissues and organs.

First-Pass Metabolism

initial metabolism of a drug that occurs in the liver after absorption from the gastrointestinal tract. It can significantly affect a drug's bioavailability.

Concentration Gradient

the difference in concentration of a substance between two areas or compartments. It can influence the movement of drugs within the body.

Membrane

a thin, selective barrier composed of phospholipid bilayers that separates different compartments within the body. It plays a crucial role in drug transport and distribution.

Lipid-Soluble Drugs

compounds that can easily dissolve in lipids (fats) and have an affinity for lipid-rich tissues in the body

Passive Diffusion

process by which drugs move across cell membranes from an area of higher concentration to an area of lower concentration without the use of energy.

What is a neuron and its role in the nervous system?

nerve cell that transmits information in the nervous system.

In what ways might types of neurons be different from each other?

Types of neurons can differ in their shape and function. Sensory neurons carry sensory information, motor neurons control muscles, and interneurons connect other neurons in the brain.

Can neurons transport chemicals along the axon? Why is this useful?

Yes, neurons can transport chemicals (neurotransmitters) along the axon. This is useful for transmitting signals from one neuron to another, allowing communication in the nervous system

Explain the structure and purpose of the neuronal membrane.

The neuronal membrane is like a cell's skin. It separates the inside of the neuron from the outside. It controls the flow of ions in and out, which is crucial for generating electrical signals.

What are some ways that ions can enter or leave a neuron?

Ions can enter or leave a neuron through channels in the membrane. These channels can be ligand-gated (controlled by neurotransmitters) or voltage-gated (controlled by electrical changes).

How is a ligand-gated channel different from a voltage-gated channel?

Ligand-gated channels open when a specific chemical (neurotransmitter) binds to them. Voltage-gated channels open in response to changes in electrical voltage across the membrane.

What are a few of the roles that glial cells play in nervous system function?

Glial cells support and protect neurons. They help nourish neurons, provide insulation (myelin), and assist in cleaning up debris. Astrocytes regulate the environment around neurons.

What is the resting potential and why is it useful?

The resting potential is the neuron's stable, negative charge when it's not sending signals. It's useful because it sets the stage for rapid signaling by creating an electrical gradient.

Arrangement of positive and negative ions and their movement?

Neurons have more negative ions inside and more positive ions outside. Diffusion and electrostatic pressure, along with the membrane, control ion movement. Ions move to balance charges.

How do gated channels and ion movement produce local potentials (EPSP/IPSP)?

Gated channels open due to signals. When sodium ions enter, it causes depolarization (EPSP). When potassium or chloride ions enter, it can cause hyperpolarization (IPSP).

How do depolarizations add up until an action potential is generated (integration)?

Depolarizations from EPSPs accumulate at the axon hillock. If they reach a threshold, voltage-gated channels open, and an action potential is produced.

How does ion movement produce an action potential?

Action potentials are generated when voltage-gated sodium channels open, allowing an influx of sodium ions. This rapid depolarization propagates down the axon as a signal.

Why are EPSP’s “excitatory” and IPSP’s “inhibitory”?

EPSPs make the neuron more likely to fire an action potential (excitatory). IPSPs make it less likely (inhibitory) by hyperpolarizing the membrane.

Basic layout of the nervous system and subdivisions?

The nervous system has the central nervous system (CNS: brain and spinal cord) and peripheral nervous system (PNS: nerves outside CNS). Subdivisions include the autonomic, somatic, and enteric systems.

Explain directional terms:
Dorsal:
Ventral:
Anterior:
Posterior:
Superior:
Inferior:
Medial:
Lateral:
Proximal:
Distal:
Rotal:
Caudal:

1. Dorsal: back of an organism

2. Ventral: Ventral refers to the front or lower side of an organism or structure.

3. Anterior: toward the front

4. Posterior: toward the back

5. Superior: above or higher in location. For example, the head is superior to the neck.

6. Inferior: below or lower in location. For instance, the feet are inferior to the knees.

7. Medial: closer to the midline of the body

8. Lateral: farther away from the midline

9. Proximal: Proximal refers to a position closer to the point of attachment or the trunk of the body. For example, the shoulder is proximal to the hand.

10. Distal: Distal indicates a position farther away from the point of attachment or the trunk. The fingers are distal to the wrist.

11. Rostral: toward the front of the body

12. Caudal: Rostral means toward the rear/tail of the body

Can any structure outside the CNS initiate behavior (on its own)?

No, structures outside the CNS cannot initiate behavior independently; they need signals from the CNS.

How are the structures in the CNS organized hierarchically?

The CNS is organized hierarchically, with the brain controlling higher functions, the brainstem regulating basic functions, and the spinal cord handling reflexes and simple processing.

What kinds of information flow through the spinal cord?

Sensory information travels up to the brain, and motor commands travel down from the brain through the spinal cord.

Function of parts of the brainstem and diencephalon?

The brainstem regulates basic functions like breathing and heartbeat. The diencephalon includes the thalamus (relay center) and hypothalamus (controls body functions).

Where to find basal ganglia and limbic system?

The basal ganglia are deep within the brain and control movement. The limbic system is near the center of the brain and is involved in emotions and memory.

Where is the cortex and related structural terms?

The cortex is the outer layer of the brain, responsible for complex thinking. Structural terms include gyri (ridges), sulci (grooves), and lobes (sections of the cortex).

Neuron

specialized cell in the nervous system that helps transmit information.

Soma

cell body of a neuron, which contains the nucleus and essential cellular components.

Dendrites

branches of a neuron that receive incoming signals from other neurons.

Axon

long, thin structure that transmits signals away from the neuron's cell body

Axon Hillock

region where the axon connects to the cell body and decides whether to send a signal.

Terminal Button

small structures at the end of axons that release neurotransmitters to communicate with other neurons.

Myelin.

fatty substance that insulates and speeds up the transmission of signals along axons.

Synapse

tiny gap between neurons where communication occurs through chemical or electrical signals.

Axoplasmic Transport

the movement of materials along the axon of a neuron.

Anterograde Transport

transport s materials from the cell body toward the axon terminals.

Retrograde Transport

moves materials from the axon terminals toward the cell body.

Membrane

thin barrier that surrounds a cell, controlling what enters and exits.

Cytoplasm

jelly-like substance inside a cell, where many cellular processes occur.

Extracellular Fluid

the liquid outside cells that contains ions and nutrients.

Ion

charged particle, like sodium (Na+), potassium (K+), or chloride (Cl-).

Channel

passageway in a cell membrane that ions can flow through.

Gated Channel

a channel that opens or closes in response to specific signals.

Ligand-Gated Channel

channels that open when a chemical signal (ligand) binds to them.

Voltage-Gated Channel

channels that open in response to changes in electrical voltage.

Glia

support cells in the nervous system.

Astrocyte

glial cells that support and nourish neurons.

Microglia

glial cells that protect the brain from infections.

Oligodendrocyte

create myelin in the central nervous system.

Schwann Cell

create myelin in the peripheral nervous system.

Resting Potential

the stable, negative charge of a neuron when it's not active

Diffusion

the movement of ions from areas of high concentration to low concentration