Ch 4. Neurotransmission (pg 79-90) Flashcards
4 criteria to be a NT
(a) the substance is synthesized within the neuron by coexisting enzymes,
(b) the substance is released in response to cell depolarization,
(c) the substance binds to receptors to alter the postsynaptic cell, and
(d) the substance is removed or deactivated by some mechanism within the synaptic cleft
peptides are what type of NT
large molecule
can nT release different substances at different synapses?
yes
neurons are classified according to?
the primary NT they release
cholinergic neurons
neurons that release acetylcholine
adrenergic and noradrenergic
neurons that release epinephrine and norepineprine
the effect of a NT depends on?
the nature of the receptors it binds to
2 types of agonistic interference
- direct agonistic (mimics completely)
- partial agonistic (only activates receptor weakly)
Some neurotransmitter receptor complexes have more than one binding site
–> called?
non competitive binding
acetylcholine is made from combining?
acetate and choline with the help of enzyme choline acetyltransferase
2 major system of cholinergic neurons that project through the brain
- basal nucleus of Meynert
and medial septal nuclei (project fibers through entire neocortex) - mesopontine tegmentum (also projects to lots of places and plays a role in REM)
Nicotinic cholinergic receptors are?
Muscarinic cholinergic receptors are ?
- ionotropic
- metabotrophic
monoamines means what?
synthesized from a single a.a
rate-limiting enzyme
the amount of a.a synthesized depends on the availability of that enzyme
dopamine beta-hydroxylase converts?
dopamine –> norepinephrine
phenylethanolamine-N-methyl-transferase converts?
norepineprhine –> epineprhine
in what system does dopamine act as a neurohormone?
tuberoinfundibular pathway
the circulatory system that connects the hypothalamus and pituitary gland
hypophyseal portal system
dopamine cell bodies in the substantia nigra of the midbrain project their axons to two regions of the striatum
–> what pathway is this? and what does it play a role in?
nigrostriatal pathway
- motor function
pathway from the ventral tegmental area to the cortex
mesocortical pathway
pathway from the tegmental area to the nucleus acumbens
mesolimbic pathway
dysfunction of NE=
attentional deficits and depression
4 noradrenergic receptors : alpha1, beta1, beta 2, and alpha2,
–> what one is inhibitory?
alpha 2
major collection of cell bodies for seratonin are in? and they are called?
raphe nuclei or the pons
- dorsal raphe nucleus and median raphe nucleus
how many of the 22 a.a act as NT
8
2 most widespread a.a that act as NT
GABA and glutamate
drugs that inhibit? also impede learnign and memory
NMDA (a receptor of glutamate)
the enzyme that converts glutamate to GABA
decarboxylase
23 classes of GABA receptors
GABAa that controls Cl- ion influx and GABAb that inhibit Ca2+ channels and indirectly controls K+ channel to hyperpolarize cell
glycine is made from ? and antagonized from the drug?
serine, strychnine (in a poison nut tree)
glycine receptors are also blocked by?
caffeine
adenosine is made of
ribose and adenine
all cells contain? for it is required for basic life processes
adenosine
When neurons are running low on oxygen or energy, they release ?, which causes dilation of blood vessels in the cells’ proximity and a consequent increase in blood flow and in fuel and oxygen supply to the neurons
adenosine
anandamide (meaning “internal bliss”) and arachidonylglycero
–> both are?
2 major cannaboinoids
is a soluble gas produced in many cells throughout the body where it plays an important role in vasodilation and blood flow
nitric oxide
