Physiological Psychology Test 2

Botulinum toxin

-Action: Blocks release of Ach, binds to postsynaptic membrane to prevent Ca+ influx, leads to paralysis -Improperly preserved food (food poisoning) -Considered most potent poison on earth; 250 g./1/2 lb. is enough to kill everyone on earth

Insecticides

-Action: Deactivation of Ach-Esterase- leads to a potent Ach effect

Amphetamines

-Action: Facilitate the release of DA and NE, acts as agonist and inhibits reuptake (NT in synaptic cleft longer) -Reach synapse all over the brain -Easily crosses BBB -Powerful behavioral stimulant to wake people up, CNS is arousal system -Prolonged use: Amphetamine Psychosis

Nicotine

-Action: Facilitation of Ach and acts as Agonist -very violent poison: enough Nicotine in 4 cigarettes (1/2 cigar) to kill a human, but burned off -stimulates both autonomic and skeletal systems -with strychinine, found in rat poisons -extremely addictive

Ritalin

-Action: Norepinepherine and dopamine reuptake inhibitor -CNS stimulant -Treatment of ADD and ADHD (CT scans of ADHD brains show decreased activity in brain centers critical to concentration and goal-directed activities)

Lead poisoning

-Action: collects in synaptic regions leading to inhibition of Ach, impairment of DA uptake, Na+ - K+ pump, thus disrupting the normal resting potential -General feelings of ill health, moderate fatigue, mental sluggishness, impairment of IQ in children -Pencil lead cannot cause lead poisoning (clay and graphite)

Black widow spider

-Action: facilitates the release of Ach -overexcitation due to to dumping Ach leads to muscle spasms

Caffeine

-Action: prolongs life of NT by competing with adenosine for its presynaptic receptor sites. Adenosine is a neuromodulator that produces behavioral sedation by inhibiting release of DA/NE -Leads to higher heart rate, neuroses, hyperactivity of the muscles -1 cup of coffee has an affect for about 2-3 hours -Natural insecticide

Lithium

-Action: speeds up reuptake of NE, resulting in faster inactivation and less NE effect when released -Used to treat mania

Disruption

-Acts as an antagonist (blocks neurotransmitter by combining with receptor molecules) -Blocks neurotransmitter from being released -Blocks synthesis or storage of neurotransmitters in the axon terminals

Cobra venom

-Attachment to muscle receptors is permanent, thus you would need to grow new receptors (3 weeks) -King cobra is the longest venomous snake (18.5 ft) -Not the most toxic, but bite allows injection of a large amount of venom -Few minutes to kill a human, 3 hours to kill an elephant -Primarily neurotoxic, attacks CNS -> cardiovascular collapse -> coma -> respiratory failure

Wiring patterns of chemical synapses

-Axosomatic synapse -Axodendritic synapse -Axoaxonic synapse

Krait snake

-Binds to Acetylclorine receptors at neuromuscular junctions leading to paralysis, respiratory failure, death -16x more potent than cobra -1 bite could kill 24 men

Antabuse

-Blocks enzyme that takes care of acetaldehyde, allowing it to build up in the body -Accumulation of acetaldehyde leads to toxicity: headaches, nausea, vomiting, drowsiness, hangover

Rohypnol (Date rape drug)

-CNS depressant (sedation, confusion, impaired coordination and judgment, memory loss) -Both physically and psychologically incapacitated -Colorless and tasteless -Reformulated to dye the liquid blue

Curare

-Action: Ach antagonist -Blocks action of Ach specifically at neuromuscular junction -Used as poison on arrow tips by South American Indians -Paralyzes instead of kills- thus good for hunting parties

Atropine

-Action: An antagonist, it attaches/combines with receptor sites on postsynaptic membrane at neuromuscular junctions -Tranquilizes smooth muscle glands -Does not act on CNS -Antispasmodic: found on the back label of insecticides

Local anesthetics

-Action: Blockade of increase in membrane permeability to sodium during action potential -Japanese puffer fish example

Tetanus toxin

-Action: Blocks activity of/at inhibitory synapses, causing strong involuntary contraction of muscles -Often fatal -Strong contractions of muscles, especially those of the neck and jaw (lockjaw) -Incubation 3-21 days (depends on distance from the CNS)

How to calculate therapeutic index?

Give drug to lab mice to obtain 2 numbers: 1. the dose that produces the desired effect in 50% of mice 2. the dose that produces a toxic effect in 50% of mice TI= toxic mg/kg / desired mg/kg Toxic dose is __x higher than effective dose

Synaptic transmission

How a neuron communicates with another neuron

Inhibitory PSP (IPSP)

Hyperpolarizes the Post Synaptic neuron. Allows k+ to diffuse out and/or Cl- to diffuse into the cell.

Intravenous (IV) injection

Injection of a substance directly into a vein

Intraperitoneal (IP) injusction

Injection of a substance into the peritoneal cavity-- the space that surrounds the stomach, intestines, liver, and other abdominal organs

Intramuscular (IM) injection

Injection of a substance into the space beneath the skin

Serotonin

Involved in mood and sleep

True or False: Neural integration occurs at the cellular level

True

The lower the TI,

the more care to be taken in prescribing the drug

Axoaxonic synapse

Axon terminal ends on another axon

Axosomatic synapse

Axon terminal ends on cell body

Drug effects on synaptic transmission (2)

-Facilitation -Disruption

Anticonvulsants

-Inhibit excitatory NT's -Enhance Cl- channels -Stabilizes Na+ channels, meaning that fewer are available to open, making brain cells less excitable or likely to fire

Synaptic integration

-Neurons in the brain receive thousands of synaptic input from other neurons. -Synaptic integration is the term used to describe how neurons "add up" these inputs before the generation of a nerve impulse or action potential. -The ability of synaptic inputs to affect neuronal output is determined by a number of factors.

Marijuana

-Plant contains 400 chemicals, 60 of which are cannabinoids (psychoactive compounds) -THC is the cannabinoid with the biggest impact on the brain -Associated with short-term memory, thought, concentration -Many THC receptors in the hippocampus

Poison Dart Frog

-Prevents Na+ channels from closing -Blocks neuromuscular transmission resulting in muscular/respiratory paralysis, death -Lethal dose for 150 lb. person is equivalent to the weight of 2-3 grains of salt -Toxin released from glands on the back or behind the ears

Two mechanisms of Neurotransmitter Deactivation

-Reuptake -Deactivating enzymes

Atypical antidepressents

-SSRI (selective serotonin reuptake inhibitors) -Work to increase serotonin in synaptic cleft...this increase is immediate although therapeutic effects may take 1-2 weeks -Success is 85%

Facilitation

-Stimulates release of neurotransmitters -Blocks inactivation of neurotransmitters -Acts as agonist (acts like or mimics the neurotransmitter)

Indirect agonist

A drug that attaches to a binding site on a receptor and facilitates the action of the receptor; does not interfere with the binding site for the principal ligand

Indirect antagonist

A drug that attaches to a binding site on a receptor and interferes with the action of the receptor; does not interfere with the binding site for the principal ligand

Receptor blocker

A drug that binds with a receptor bud does not activate it; prevents the natural ligand from binding with the receptor

Direct agonist

A drug that binds with and activates a receptor

Agonist

A drug that facilitates the effects of a particular neurotransmitter on the postsynaptic cell

Antagonist

A drug that opposes or inhibits the effects of a particular neurotransmitter on the postsynaptic cell

Norepinephrine (NE)

A hormone released during stress

Presynaptic heteroreceptor

A receptor located in the membrane of a terminal button that receives input from another terminal button by means of an axoaxonic synapse; binds with the neurotransmitter released by the presynaptic terminal button

Epinephrine (Adrenaline)

A stress hormone

Direct antagonist

A synonym for receptor blocker

Three differences between Action potential and post synaptic potential

AP- occurs only in axon, caused by integration of PSP coming together, always excitatory, all or none. PSP- Can occur in dendrite, muscle, etc., originates from neurotransmitter attachment to PS membrane, excitatory or inhibitory.

Sublingual administration

Administration of a substance by placing it beneath the tongue

Intracerebral administration

Administration of a substance directly into the brain

Topical administration

Administration of a substance directly onto the skin or mucous membrane

Intracerebroventricular (ICV) administration

Administration of a substance into one of the cerebral ventricles

Oral administration

Administration of a substance into the mouth, so that it is swallowed

Intrarectal administration

Administration of a substance into the rectum

Inhalation

Administration of a vaporous substance into the lungs

Axodendritic synapse

Axon terminal ends on a dendrite

Noncompetitive binding

Binding of a drug to a site on a receptor does not interfere with the binding site for the principal ligand

Irreversible Antagonists

Cannot be broken down or they are broken down so slowly that their effect is irreversible

Catecholamine

DA/NE (appear to affect higher-order behavior)

Dose response curve

Depicts relation between drug dose and magnitude of drug effects. -Drugs can have more than one effect -Drugs vary in effectiveness (site of action, affinities for receptors) -Effectiveness of a drug is considered relative to its safety (TI)

True or false: Receiving neurons only connect with one sending neuron at a time

False. Axon terminals of sending neurons almost completely cover the body of receiving neurons.

True or False: neurons can only release one neurotransmitter

False. Dale's law believed this was true, but revisions say neurons can release more than one neurotransmitter. Furthermore, all branches of an axon release the same combination of neurotransmitters through possibly in different ratios at different branches in different times.

Therapeutic Index

Measures drugs margin of safety

Endorphins

Neuromodulators that reduce pain and enhance reinforcement

Spatial summation

Occurs when SEVERAL DIFFERENT presynaptic terminals release NT's simultaneously.

Temporal summation

Occurs with REPEATED RELEASE of NT's from one or more synaptic terminals before resting potential.

Dopamine (DA)

Promotes reinforcing effects of food, sex, and abused drugs. Also involved in schizophrenia and Parkinson's disease

Gamma-aminobutyric acid (GABA)

The predominant inhibitory neurotransmitter

Glutamate

The principal excitatory neurotransmitter in the brain and spinal cord

Pharmacokinetics

The process by which drugs are absorbed, distributed within the body, metabolized, and excreted.

Psychopharmacology

The study of the effects of drugs on the nervous system and on behavior

Acetylcholine (Ach)

Transmitter at muscles