INTRO TO NEURO CHAPTER 15

Pharmacology

Scientific study of how substances affect an organism

Physical dependence

State in which removal of the drug induces a withdrawal response

Psychopharmacology

How drugs modify behavior

Neuropharmarcology

How drugs affect the activity of brain structures

Neuropsychopharmacology

How drugs act on the brain to modify behavior

Bioavailability

Drug actions are dependent on the amount of drug available in the blood

Absorption, Distribution, Metabolism, Elimination

The primary pharmacokinetic factors include:

Oral ingestion, injection into the bloodstream, inhalation, across mucous membranes 

Routes of administration (affects rate of absorption and total amount of drug absorbed)

Active sites and inactive sites

Where are drugs distributed?

Liver

Where does metabolism usually occur?

Metabolites

Metabolism converst drugs to inactive forms called ______

Lipid soluble

Substance must be what to penetrate BBB?

Indirect drug action and specific drug action

2 ways drug can influence neural activity

Indirect drug action

Substance acts diffusely on neural membranes, effecting functions of many different proteins located in the membrane

Specific drug actions

Substance altering the signaling activity of selective targets, maybe one or a few neurotransmitter receptors

Drug tolerance

State of decreased sensitivity to the drug

Right

Drug tolrance shifts the dose-response curve to the _____

Functional tolerance

Tolerance that result from a decrease in the ability of the drug to influence the target cells (primary tolerance)

Metabolic tolerance

Tolerance that results from a decrease in the amount of drug reaching the target cells, often due to changes in liver metabolism

Contingent tolerance

Tolerance demonstrated using before-and-after experiments, development of tolerance depends on experiencing the effect of the drug

Conditioned tolerance

Tolerance that is maximally expressed in the presence of drug-predictive stimuli

Physical dependence

State in which removal of the drug induces a withdrawal response

Early views

What views focused on physical dependence and severe withdrawal?

Compusive behavior, craving & release

Today there is emphasis on what in terms of addiction?

Chronic, relapsing, behavioral

Addiction is a ___, ____, _____ disorder.

Route of administration

Addiction potential of a substance is influenced by what?

Fast onset of drug effects that have a short duration

Routes of administration that allow for (ex: IV substance use) lead to ____

Lower addiction potential

Routes of administration that are slow (oral ingestion or transdermal) have a ____

Rewarding and reinforcing

Two important important properties that drugs of abuse share

Place conditioning

Rewarding properties of a drug are commonly assessed using ____ (also called conditioned place preference)

Hedonic value

Another name for degree of award

Drug-self administration

Reinforcing properties of a drug are commonly assessed using what

True

T/F: Substance is reinforcing because it is rewarding.

Initial drug taking, habitual drug taking, drug craving and repeated relapse

Three stages of addiction?

Incentive salience hypothesis

Hypothesis that distinguishes between liking a substance and wanting a substance: positive incentive value is linked to user’s want where hedonic value = user’s liking of drug’s effect

Incentive-sensitization theory

Expectation of the pleasurable efects of drugs may become sensitized in addicts

Stress, drug priming, conditioned environmental cues

Three factors important in driving drug craving and repeated relapse

Binge drinking

Males consuing 5 or more drinks (4 or more in females) within a two-hour period

Heavy use

Binge drinking 5 or more times in the past 30 days

140 million people

Current use of alcohol people aged 12 or older

1 in 8

Ratio of heavy use users in people aged 12 or older

6 million

Current underage drinking number

1 in 5

Ratio of underage drinkers that report heavy alcohol use

5 ounce w/ 12% of alcohol

Standard drink of wine

12 ounce with 5% alcohol

Standard drink of beer

1.5 ounce with 40% alcohol

Standard drink of hard liquor

Constant rate

Alchol is eliminated at a what rate? (95% metabolized in the liver or eliminated in breath 5%) (1 standard drink per hour)

Acute tolerance

Subjective effects of alcohol are reduced during elimination (feeling sober even when BAC is above 0.08%)

CNS depressent

What class of substance is alcohol? (effects include relaxation, reduced anxiety, intoxication, impaired judgement, impaired memory, and sleep) (higher doses produce coma and death)

Metabolic tolerance

Caused by chronic alcohol use increase the production of liver enzymes involved in the metabolism of alcohol

Functional tolerance

Caused by continued presence of alcohol where receptor systems become less sensitive to the actions of alcohol

Dopamine

Alcohol increases what? (increase in action potential firing of these neurons)

Inhibits glutamate, increases GABA and opioids

What does alcohol involve when increasing dopamine?

Stimulants

This class increases arousal and bheavioral activation (cocaine, crack, amphetamine, metamphetamine)

Tremors, hyperthermia, and psychosis

Repeated use of stimulants can lead to what?

Block the dopamine transporter that removes DA from the synaptic cleft

What do stimulants do?

Mesotelencephalic reward pathway

Circuit known as the reward circuit

Intracranial self stimulation

Discovered by Olds and MIlner, where rodents pressed a lever and an electrical current is delivered to the electrode

Ventral tegmental area and nucleus accumbens

Two main areas of the reward circuit

Dopamine cell bodies

VTA contains large collection of what?

Axons of DA neurons in the VTA, also DA receptors

Nucleus accumbens has?