PSY 314 -- Chapter 15

please check your notes because this isn't complete, lol. this is just the most difficult of the terms

mesolimbic system

mesolimbic system

primary mechanism of reinforcement; cell bodies in VTA, projects to NAc and AMY; brain stimulation, natural rewards

mesocortical system

secondary mechanism; DA cell bodies in the VTA, projects to PFC

endorphins

morphine-like NTs found in the brain and pituitary gland

incentive sensitization hypothesis

sensitization of mesocorticolimbic DA systems; increased sensitivity to stimulus; stimuli is more valuable because the system has been conditioned to it

tolerance

the need to take increasingly higher doses of a drug to achieve a particular effect

withdrawal

when cessation of drug use elicits symptoms opposite to those produced by the drug [negative reinforcement]

hallucinogens

5-HT2A agonists

serotonin-like hallucinogens

same group as LSD, psilocybin, DMT

catecholamine-like hallucinogens

same group as mescaline (Peyote), DOM

LSD

psychological effects 30-90 minutes after oral administration; peak effect at 2-4 hours; strange sensory experiences even after taking it regularly, quick tolerance

hallucinogen persisting perception disorder

individuals have flashbacks, sensory experiences, years after cessation of use

THC (marijuana)

indirect glutamate antagonist

THC mechanism of action

binds to cannabinoid receptors; CBR are GPCRs which inhibit Ca2+ influx; partial agonist on CBR, antagonist at Glu terminals

anandamide

partial agonist of the CBR, endogenous ligand for the CBR

THC

injections of these result in an increase in DA in the NAcd

depressants

GABA agonist

benzodiazepines, non-bzd hypnotics (Ambien, Lunesta)

GABA allosteric agonists

mechanism of depressants

binds to GABA-A receptor, increases DA in the NAc, addictive

mechanism of action of alcohol

binds to allosteric GABA-A receptor (BZD site), increases DA in NAc

Korsakoff's Syndrome

lack of B1 which causes dmg in the limbic system and cortexa

anterograde amnesia

inability to form new memories

retrograde amnesia

severe loss of memories formed before the onset of the condition

confabulation

invented memories which are then taken as true due to gaps in memory sometimes associated with blackout

cocaine, amphetamines

DA-based stimulants

caffeine

mild reinforcement, binds to adenosine receptors in the brain, addiction leads to mildly unpleasant withdrawal effects

nicotine mechanism of action

acts on ACh nicotinic receptors; DA in NAc (reinforcement), tendency to relapse

amphetamines mechanism of action

causes DA to come out of vesicles intraneuronally, causes DA reuptake TP to run in reverse, flooding synapses with DA

Ritalin

blocks DA reuptake; weaker affinity to DAT

MDMA

serotonergic drug of abuse

MDMA mechanism of action

causes DA, NE, and 5HT to come out of vesicles intraneuronally; reuptake TP runs in reverse, flooding synapses, binds to 5HT receptors

spinothalamic tract

cell bodies in DRG; synapses and crosses into spinal cord, ascends in the lateral horn; axons in the medial lemniscus; projects to VPN of the thalamus which projects to S1

A-delta fibers

lightly myelinated and smaller diameter; used for rapid, sharp pain, initial reflex response

C fibers

unmyelinated and smallest fibers; used for slow, burning pain

spinoreticular

axons ascend to brainstem reticular formation (arousal/responding), projects to VPN, hypothalamus, cortex; used for emotional aspects of pain

descending inhibitory pain modulation

PAG in the midbrain and RVM; projects to dorsal horn of spinal cord which inhibits pain transmission

enkpehalins

morphine-like NTs found in the brain and adrenals

descending pain control pathway

DLPF activates ACC system which activates PAG, raphe nuclei, travels to dorsolateral funiculus of spinal cord, synapses on inhibitory interneurons in dorsal horn of spinal cord which release endogenous opioids

opium

raw latex fr poppy

opiates

compounds purified from opium poppy.

opioids

any molecule exhibiting the properties, natural or synthetic

opioid peptides

endogenously produced peptide molecules that activate opioid receptors

morphine

primary active ingredient in opium

codeine

secondary active alkaloid in opium

agonists of opioid receptors

MOR, KOR, DOR

Naloxone (Narcan), nalorphine

opioid antagonist

dextromethorphan

opioid analogue; cough suppressant