Chapter 11: Introduction to CNS pharmacology Flashcards
the CNS is made of a network of ___ and ___cells that carry signals throughout the brain and through the body
neurons and supporting cells
neurons send signals to each other by release of ___ at synapses
neurotransmitter
the actions of neurons are energy intensive and must be tightly regulated to have efficient ___
signal transduction
support cells include astrocytes, which are glial cells that help remove __, supply___ and make up part of the ___
neurotransmitter form synapses; nutrients; bbb
compared to body BV, vessels entering the CNS are much ___ permeable
less
the BBB is made of ___ and ___
endothelial tight junctions and the end feet of astrocytes (aka astroglia)
the arrangement of the BBB helps prevent ____ of most polar molecules and ____ are required to bring many required substances such as glucose into the CNS
passive diffusions; transporters
what type of molecules are capable of crossing the BBB by passive diffusion?
very small lipophilic
does low penetration mean no penetration in the CNS?
no
L-DOPA and glucose are very polar molecules, but have higher than expected penetrance of the CNS, why?
they are actively transported in as essential nutrients
phenobarbital and phenytoin are very lipophilic drugs, but have lower than expected levels in the CNS, why is this?
they are actively pumped out
molecules can generally cross the BBB if they are one or all of what 3 things?
small, hydrophobic, substrate for carrier
molecules generally can’t cross the BBB if they are one or more of what 2 things?
large, hydrophilic
___ is required to determine if a drug is a substrate for a transporter
experimental data
during ___, the BBB becomes more permeable and allows more molecules to cross
systemic inflammation
the majority of neuronal activity occurs at ___
synapses
NT are made and stored in the ___ nerve terminals
presynaptic
___ causes NT to be released into the synapse where it acts on ___receptors
action potential propagation; post-synaptic
the signal is terminated as the NT ____
diffuses away from the synapse
once the NT difuses away from the synapse, it can be ___ or ___ by ___ or ___ cells
degraded; taken back up by presynaptic or glial cells
some signals between neurons may involve the release of a ___ back into the synapse to retrogradely signal to the presynaptic neuron
signalling molecule
list some CNS NTs
glutamate, GABA, NE, dopamine, serotonin, endocannabinoids, glycine, neuropeptides, Ach, histamines
Glutamate (Glu) is a ___- NT made in ___ and stored in ___
excitatory, presynaptic; vesicles
when glutamate is taken up by glial cells its made into ___
glutamine
after glial cells turn glutamate into glutamine, what happens to it?
taken back into presynaptic neurone terminals so it can be made into glutamate again
what is the primary way a glutamate response is terminated?
glutamate is taken up into glial / astrocyte
