Ketamine and PCP Flashcards
PCP full name
phencyclidine
What defines a dissociative anesthetic?
creates an out body/detached from environment experience
What was PCP tested as? What behaviors resulted?
- an iv anesthetic agent
- trance-like/catatonic-like state
- vacant expression, fixed/staring gaze, reidigity or wavy flexibility
- reminiscent of catatonic schizophrenia
Side-effects of PCP injection
hallucinations, agitation, violence
How does ketamine compare to PCP?
less potent and shorter acting than PCP
Current uses of ketamine
used as an anesthetic in children and veterinary medicine
Forms of ketamine:
- crystals
- manufactured as a liquid and evaporated to form powder or pill for elicit use
- powder sprinkled on marijuana, tobacco, parsley and smoked
Behavioral effects of ketamine:
- loss of sense of time
- distoritons of body shape/size
- sensations of floating/hovering/leaving one’s body
- supernatural visions
- at one with the universe
ketamine produces a ______ increase in ______
dose-dependent; psychotic-like symptoms
dextromethorphan
- DXM or robo
- recommened dosage: 15-30mg (1/6 - 1/3 oz)
- recreational doses: 2 - +10oz
PCP, ketamine and dextromethorphan are _____ at ____ receptors
noncompetitive antagonists at glutamate NMDA receptors
glutamate is synthesized from glutamine by:
glutaminase
functions of glutamate
- used as an amino acid in protein production
- most common excitatory neurotransmitter
glutamate synthesis
-in nerve terminal: glutamine is converted to glutamate by glutaminase
fates of glutamate after release
- docks of postsynaptic glutamate receptor,
- taken up by EAAT3 on nerve terminal and packaged into vesicle by VGLUT
- taken up by EAAT1/EAAT2 on astrocyte
glutamate after uptake by astrocyte:
- glutamate is converted to glutamine by glutamine synthetase
- glutamine transported out of astrocyte and transported into nerve terminal
EAAT
excitatory amino acid transporter
VGLUT
vesicular glutamate transporter
How is glutamate converted to GABA?
GABA amino acid transferase and flutamic acid decarboxylase act on glutamate to produce GABA
GABA full name
gamma-aminobutyric acid
GAT
GABA transporter
GABA in astrocytes
- GABA taken up by astrocyte by GAT-1,2, or 3
- GABA converted to glutamate, then glutamine
- glutamine transported out of astrocyte and into nerve terminal
glutamate is an _____; example?
excitotoxin; MSG kills neurons in arcuate nucleus
Name and number of metabotropic glutamate receptors:
- mGluR1-8
- 8 subtypes
How are ionotropic glutamate receptors named?
after the selective agonsits
The ionotropic glutamate receptors and their selective agonists
AMPA- amino-propanoic acid
Kainate- kainic acid
NMDA- N-methyl-D-aspartate
All ionotropic glutamate receptors conduct _____ ions into the cell
Na+
NMDA receptors conduct ____ and ____ into the cell
Ca2+ and Na+
NMDA receptor properties
- glycine/serine and glutamate must bind to activate glutamate receptors
- thus 2 different neurotransmitters are required to activate
- contains a Mg2+ binding site
Glycine/Serine are ____ with gluatmate at NMDA receptors
co-agonists
Mg2+ binding site at resting membrane potential:
occupied, thus blocking the channel
Mg2+ binding site at depolarized potential:
unoccupied, thus the channel is unblocked
glutamate occupies NMDA receptor + insufficient membrane potential =
Mg2+ block remains
glutamate occupies NMDA receptor + suffucient membrane depolarization =
Mg2+ block released
PCP, ketamine and dextromorphan block the glutamate receptor at ____
a site other than the glutamate binding site
PCP blocks NMDA receptor ____
below the Mg2+ block
