Bio psychology ch. 4 Flashcards


Set Details Share
created 1 year ago by Luna_Bean
6 views
show moreless
Page to share:
Embed this setcancel
COPY
code changes based on your size selection
Size:
X
Show:

1

Exogenous substances

substances from external sources - have been used for ages to change the functioning of the brain and body

2

endogenous

  • released by the presynaptic neuron
  • (internal) substance - a neurotransmitter

3

2 basic kinds of neurotransmitters

  • Ionotropic receptors
  • Metabotropic receptors

4

Ionotropic receptors

quickly change shape and open or close an ion channel when the transmitter molecule binds

5

Metabotropic receptors

  • alter chemical reactions in the cell
    • Use a system of second messengers to open an ion channel
    • May start chemical reactions to alter gene expression

6

Criteria for neurotransmitter classification

  • It is synthesized in presynaptic neurons and stored in the axon terminal
  • It is released when an action potential reaches axon terminals
  • It is recognized by receptors on the postsynaptic membrane
  • Causes changes in a postsynaptic cell
  • Blocking its release interferes with a cell’s ability to affect a postsynaptic cell

7

Types of neurotransmitters

  • Amino acids neurotransmitters
      • GABA, Glutamine
  • Peptide (neuropeptides)
      • A bunch of amino acids put together
      • Bonding hormones and released
      • Oxytocin
  • Amine
    • Serotonin
    • Dopamine
    • acetylcholine
  • Gas
    • Carbon monoxide
    • Nitrate oxide

8

Glutamate

  • most widespread excitatory transmitter
    • AMPA and NMDA receptors

9

Gamma-aminobutyric acid (GABA)

  • the most widespread inhibitory neurotransmitter
    • GABA receptors- ionotropic; inhibitory; allow Cl- ions into the cell
    • Benzodiazepines (valium, Ativan) mimic GABA and are used to relax muscle, induce sleep and reduce anxiety

10

4 classical neurotransmitters modulate brain activity

  • Serotonin
  • Acetylcholine
  • Dopamine
  • Norepinephrine

11

Acetylcholine

  • 4 important amine transmitters project throughout the brain
  • plays a major role in the forebrain

Many cholinergic neurons are found in the basal forebrain

12

Dopamine

  • important for many aspects of behavior
    • Mesostriatal pathways are important for motor control- originate in the substantia nigra of the midbrain. Parkinson’s disease results from the loss of neurons.
    • The mesolimbocortical pathway originates in the ventral tegmental area (VTA) and is important for learning shaped by positive reinforcement

13

Norepinephrine

  • (noradrenaline) is important in the control of many behaviors franging from alertness -> mood -> sexual behavior

Noradrenic neurons are found in the locus coreulers and lateral temgmental area

14

Serotonin

  • Participates in the control of many aspects of behavior: mood, vision, anxiety, sexual behavior, sleep etc.

Serotonergic neurons originate along the midline of the midbrain and brainstem in the raphe nuclei

15

Many peptides act as neurotransmitters

  • Opioid peptides mimic opiate drugs such as morphine and reduce the perceptipon of the brain
  • Peptides discovered in the gut are also made by neurons in the spinal cord and brain (substance P, cholecystokinin)
  • Peptide hormones such as oxytocin and vasopression, contribute to memory and pair-bonding

16

A gas neurotransmitter differs from other transmitters in 3 ways

  • Produced outside axon terminals - mainly in dendrite- and diffuses out if the neuron as soon as it is produced
  • No receptors are involved; it diffuses into the target cell and activates second messengers

It can function as a retrograde transmitter by diffusing from the postsynaptic neuron back to the presynaptic neuron

17

Agonists

  • drugs that occupy receptors and activate them
  • full-activation
  • When a drug activates the receptor, it is acting as an

18

Antagonist

  • drugs that occupy receptors but do not activate them
    • Block receptors activation by agonists
  • When a drug binds a receptor without activating it and also blocks it

19

Ligand

  • any substance that bind to a receptor
  • an endogenous ligand binds to a receptor and activate a change, (opening an ion channel

20

bioavailable

  • free to act on the target- varies with route of administration

21

Biotransformation:

produces active metabolites that may produce side effects

22

Pharmacokinetics:

refers to all factors that affect the movement of drugs from their entry into the body to their exit from the body

23

Dose

  • DRC- Dose-response curve
  • Blood-brain barrier

24

Binding affinity

  • The degree of the chemical attraction between ligand and receptor
  • Intrinsic activity
    • is the ability of a bound ligand to activate the receptor

25

Tolerance

  • Reduced efficacy of drug
  • Metabolic tolerance
  • Functional tolerance

26

Functional Tolerance

  • Target tissue alters it’s sensitivity to the drug by changing the number of receptors

27

Down-regulation

response to agonists - fewer receptors

28

up-regulation

response to antagonists more receptors

29

metabolic

  • Organ systems become more effective at eliminating the drug
    • Ex. liver w/ repeated alcohol use

30

Cross tolerance

  • Tolerance to one drug is generalized to other drugs in its class
    • Ex. taking an antidepressant and would be tolerant to other forms

31

1st Generation (Antipsychotics and schizophrenia)

(neuroleptics) are in a class of drugs that alleviate symptoms of schizophrenia, typically by blocking dopamine D2 recpetors

32

2nd Generation (Antipsychotics and schizophrenia)

Act on receptors in addition to and may relieve symptoms resistant to typical antipsychotics

33

MAOIs- monoamine Oxidase Inhibitors

Inhibitors prevent the breakdown of monoamines at the synapses

34

SSRIs

  • Like Prozac or celexa, act specifically at the serotonergic synapse
    • Selective serotonin reuptake inhibitors
  • Block reuptake of serotonin and norepinephrine

35

SNRI’s/Tricyclic

  • Promote an accumulation of synaptic transmitter, by blocking the reuptake of transmitter molecules into the presynaptic terminal

36

Antidepressants

  • drugs are used to treat disturbances of mood called affective disorders

37

Depressants

drugs that reduce nervouse system activity

38

Barbiturates

early anxiolytics and sleep aids, depress nervous activity- addictive and easy to overdose on

39

Benzodiazepines

act at agonistis on GABAa receptors and enhance the inhibitory effects of GABA

40

Opium

  • records of use date to at least 2100 BC
  • Resin within the poppy flower us harvested and used as a analgesic

41

Morphine

isolated ingredient from the opium poppy, which contains the analgesic