Chapter 5: Catecholamines Flashcards
NE or DA: Working memory, behavior, motivation.
DA
NE or DA: Sustained attention/alertness, response to environmental stimuli
NE
NE or DA: Attention.
both
Adrenaline refers to…
NE and EPI
Adrenergic/nonadrenergic refer to…
NE and EPI
Dopaminergic refers to…
DA
Secretion of NE and EPI:
NE: adrenal medulla or brain (LC)
EPI: adrenal medulla
Secretion of DA:
within the brain, in the ventral tegmental area (VTA) or the substantia nigra (SN)
Catecholamine synthesis begins with […] AA.
tyrosine
Dopaminergic neurons have tyrosine […] and […] AA […].
hydroxylase (TH); aromatic; decarboxylase
Nonadrenergic neurons have…
TH, AADC, and DBH
What is the importance of TH in regards to synthesis?
TH is the rate-limiting enzyme in the pathway and determines the overall rate of DA and NE synthesis
Activity of TH is regulated by several factors:
- stress; NE neurons are highly active and stimulates TH for synthesis
- cell firing; stimulates TH through phosphorylation of the enzyme by 2nd messengers and protein kinases
Catecholamine synthesis can be increased by administering […] such as tyrosine or […].
precursor; L-DOPA
Tyrosine and L-DOPA are used to treat…
Parkinson’s disease
What blocks and prevents TH synthesis?
AMPT: alpha-methyl-para-tyrosine
Beta-hydroxylase is present only in cells that use […] as a NT.
NE
T/F: Catecholamines are packaged into vesicles.
true
What transports the vesicles containing catecholamines?
VMAT: vesicular monoamine transporter
VMAT can be blocked by the drug […].
reserpine
If DA and NE are not protected in vesicles, […] occurs, their […] which causes strong […] and […].
breakdown; levels drop; sedation; depression
Catecholamine theory of depression: Administration of DOPA could…
reverse the effects of strong sedation, depression, and breakdown of DA and NE
Catecholamines are normally released by […] when a […] reaches the axon terminal.
exocytosis; nerve impulse
Drugs that affect the release of catecholamines:
amphetamine and methamphetamine
At low doses of amphetamine/methamphetamine…
increased locomotor activity
At higher doses of amphetamine/methamphetamine…
stereotyped behaviors
repetitive head and limb movements, intense sniffing, licking, biting
[…] inhibit catecholamine release (receptor).
autoreceptors
Autoreceptors found on catecholamine neurons enhance to opening of […].
K+ voltage-gated channels
Autoreceptors open voltage gates that reduce the […] via VGCCS and thus […].
Ca2+ influx; vesicle exocytosis
Somatodendritic autoreceptors inhibit NT release indirectly by…
reducing the rate of firing of the cell
VGCCs = [...] VDCCs = [...]
voltage gated calcium channels
voltage dependent calcium channels