Chapter 6: Drugs and Hormones Flashcards
Attention-Deficit/Hyperactivity Disorder (ADHD)
developmental disorder characterized by core behavioral symptoms including impulsivity, hyperactivity, and/or inattention
Psychopharmacology
study of how drugs affect the nervous system and behavior
Psychoactive Drug
substance that acts to alter mood, thought or behavior
is used to manage neuropsychological illness, and may be taken recreationally
Agonist
substance that enhances neurotransmitter function
Antagonist
substance that blocks neurotransmitter function
Tolerance
decrease in response to a drug with passage of time
Fetal Alcohol Spectrum Disorder (FASD)
range of physical and intellectual impairments observed in some children born to alcoholic parents
Amphetamine
synthetic compound that increases the neurotransmitter dopamine in the synaptic cleft by reversing the dopamine transporter
Dopamine Hypothesis of Schizophrenia?
idea that excess dopamine activity causes symptoms of schizophrenia
Major Depression
mood disorder characterized by prolonged feelings of worthlessness and guilt, disruption of normal eating habits, insomnia, a general slowing of behavior, and frequent thoughts of suicide
Monoamine Oxidase (MAO) Inhibitor
drug that blocks the enzyme monoamine oxidase from degrading such neurotransmitters as 5-HT, NE and DA
Tricyclic
drug, characterized by its three-ring chemical structure, that blocks 5-HT reuptake transporter proteins
Selective Serotonin Reuptake Inhibitor (SSRI)
drug that blocks 5-HT reuptake into the presynaptic terminal and most commonly used to treat depression
Competitive Inhibitor
drug used to treat overdoses and opioid addiction, an example is naloxone, which acts quickly to block opioid action by competing with the opioid for binding sites
How do drugs and hormones influence brain and behavior?
principles of psychopharmacology
psychoactive drugs
factors influencing individual responses to drugs
explaining and treating drug abuse
hormones
What is psychopharmacology?
study of the ways drugs affect the nervous system and behavior
What are drugs?
chemical compounds administered to produce a desired change
improvement of physical/mental symptomatology
What are psychoactive drugs?
substance that acts to alter moods, thought, or behavior, used to manage neuropsychological illness
often used recreationally
What are the routes of drug administration?
the way a drug enters/passes through the body to reach target
a psychoactive drug has to reach it’s target to work
can be administered: orally or inhaled, absorbed through skin or mucous membranes, injected into the bloodstream, into a muscle, or even into the brain
What is the effect of injecting a drug directly into the brain?
allows it to act quickly in low doses because it encounters fewer barriers
What is the effect of ingesting a drug orally?
safest, easiest, and most convenient way to administer them
drugs that are weak acids pass from the stomach into the bloodstream
drugs that are weak bases pass from the intestines to the bloodstream
has the most barriers to the brain
ingestion>absorption by stomach/small intestine
What is the effect of injecting a drug in muscles?
encounter more barriers than do drugs inhaled
What is the effect of inhaling drugs into the lungs?
encounter few barriers en route to the brain
gases or aerosols penetrate the cell linings of respiratory tract easily
absorbed by membranes into bloodstream almost immediately after inhalation
What is the effect of injecting drugs into the bloodstream?
encounter the fewest barriers to the brain but must be hydrophilic
when injected into bloodstream a drug passes through less obstacles
with each obstacle eliminated en route to the brain, a drug’s dosage can be reduced by a factor of 10
How do drugs enter the bloodstream in the stomach?
drug must be water-soluble
diluted over the body through blood to reach target
What is the effect of drugs being absorbed by the skin?
drugs contained in adhesive patches are absorbed through the skin and into the bloodstream
the skin is made out of protective layers
small molecule drugs can penetrate the skin barrier
What is the factor of 10 rule?
1 milligram (1000 micrograms) of amphetamine produces a noticeable behavioral change orally
if inhaled into the lungs or injected into the blood, circumventing the stomach, a dose of just 100ug yields the same results
if amphetamine is injected into the cerebrospinal fluid, bypassing both the stomach and the blood, 10ug us enough to produce an identical outcome
1ug if the drug is applied directly to target neurons
What is the blood brain barrier?
the body presents a number of barriers to the internal movement of drugs: cell membranes, capillary walls, and the placenta
the blood-brain barrier prevents most substances from entering the brain via the bloodstream
protects the brain’s ionic balance
denies neurochemicals that can disrupt neural communication
protects the brain from circulating hormones and form toxins/infectious diseases
What are endothelial cells in the blood-brain barrier?
endothelial cells form a layer that lines the blood vessels, regulate exchanges between bloodstream and surrounding tissues
endothelial cells in capillaries throughout the body are not tightly joined
it’s easy for substances to move out and into the bloodstream
endothelial cell walls in the brain are fused to form tight junctions, so most substances cannot squeeze between them
What are astrocytes in the blood-brain barrier?
astrocytes provide a route for the exchange of food and waste between capillaries and the brain’s extracellular fluid, as well as from there to other cells