Module 7 - Neuropharm Flashcards
What is the primary excitatory neurotransmitter in the CNS and also has important actions in the PNS?
Glutamate
Where does glutamate come from?
Either from glucose metabolism in the Kreb’s Cycle or from GABA metabolism in the glial cells
What does glutamate bind to what type of receptors?
AMPA and NMDA
How is glutamine synthesized?
from GABA metabolism* in the glial cells of the CNS (astrocytes, mainly).
What is glutamate metabolism related to?
formation of glutamine or α-ketoglutarate (which are not neurotransmitters) or GABA (an inhibitory neurotransmitter)
What is the synthetic enzyme of glutamine?
Glutaminase to make glutamate
What is the enzyme that turns glutamate back into glutamine?
Glutamine synthetase
True or False
Glutamate levels in the brain are tightly controlled
T
After glutamate activates its receptors, it is rapidly removed from the synaptic cleft between neurons by _________ _______________ __________located on neurons and astrocytes.
glutamate transporters (EAATs)
In astrocytes, what is glutamate covered to glutamine by?
Glutamine synthase
What is considered the most important neurotransmitter in the brain?
Glutamate
What is glutamate required for excitation?
waking behavior, learning and memory storge and recall, and management of planning activities
many reflexes, primarily, the afferent limb of reflex activity.
What is the first receptor of glutamate to be characterized?
AMPA site
What happened when the glutamate is bound to AMPA receptor?
acts very quickly to open non-specific channels to both Na+ and K+.
Where are the NMDA receptors in the brain located? What are they necessary for?
NMDA receptors in the brain, particularly the hippocampus, are necessary for the process called “long term potentiation”, which underlies the production of long-term memory
What receptors are requiring the other to complete complex actions of excitation?
AMPA and NMDA
______ sites help keep _____ sites from allowing too much calcium from entering the cell.
AMPA; NMDA
What can happen if too much Ca2+ comes into the cell?
Too much Ca2+ coming into the cell causes excitotoxicity: concussion and hypoxia
What happens if there is not adequate ATP due to respiratory hypoxia or other decrease in O2?
there won’t be an adequate way to get rid of the excess Ca2+
What can happen if there is too much glutamate due to increased excitation?
(caused by concussion or TBI), intracellular levels of Ca++ can cause cell death by apoptosis.
What can help mitigate the effects of ROS driven by Ca2+
Antioxidants and glutathione (GSH)
What is the major inhibitory neurotransmitter in the central nervous system (CNS)?
GABA
How is GABA synthesized?
in neurons, mainly from glutamic acid (glutamate) derived from the Kreb’s cycle…. See the next slide.
What enzymes causes inactivation of GABA?
Reuptake and GABA-T (GABA-transaminase)