Neuro Phys I

Question 1

_________ nerves release acetylcholine

Answer 1

Parasympathetic

Question 2

What receptor types does Ach excite?

Answer 2

Nicotinic and muscarinic

Question 3

Where are nicotinic receptors located?

Answer 3

Synapses between pre and postsynaptic neurons

Question 4

Where are muscarinic receptors located?

Answer 4

ALL effector cells stimulated by postsynaptic parasympathetic fibers

Question 5

Nicotonic receptors = ____synpatic
Muscarinic receptors = ____synpatic

Answer 5

Nicotinic = pre
Muscarinic = post

Question 6

Where is acetylcholine active?

Answer 6

Most parts of the brain

Question 7

What happens to excess acetylcholine that remains in the synaptic cleft?

Answer 7

Broken down into choline and acetate byproducts

Question 8

What is the effect of Ach binding on Na+ channels?

Answer 8

Na+ channels open when Ach binds, making Ach EXCITATORY

Question 9

What is the difference between an ionotropic receptor and a metabotropic receptor?

Answer 9

Ionotropic = NT binding induces ion channels to open
Metabotropic = NT binding acitvates G protein coupled receptors

Question 10

Example of an ionotropic receptor and an example of a metabotropic receptor

Answer 10

Ionotropic = nicotinic
Metabotropic (aka G protein coupled receptors) = muscarinic

Question 11

What is the primary NT of postsynaptic sympathetic nerves?

Answer 11

Norepinephrine

Question 12

What receptors does NE stimulate?

Answer 12

Alpha and beta adrenergic receptors

Question 13

How is NE removed from the synaptic cleft?

Answer 13

Reuptake OR metabolized by monoamine oxidase (MAO) or catechol-O-methyltransferase

Question 14

Precursor of NE?

Answer 14

Tyrosine

Question 15

Where do you find high concentrations of serotonin?

Answer 15

Platelets and GI system

Question 15

How do cocaine and TCAs impact NE levels in the synaptic cleft?

Answer 15

Inhibit NE reuptake, causing INCREASED levels of NE in the cleft

Question 15

What kind of receptors does serotonin bind to?

Answer 15

5-HT receptors

Question 15

What is the precursor for serotonin?

Answer 15

5-HT

Question 16

What is the role of serotonin?

Answer 16

Regulate mood and sleep

Question 17

What medication inhibits 5HT transporters to prevent serotonin uptake?

Answer 17

SSRIs

Question 18

Why is serotonin linked to depressive disorders?

Answer 18

5-HT widely found throughout the limbic system

Question 19

Where is dopamine released from?

Answer 19

Hypothalamus

Question 20

What does dopamine do to prolactin?

Answer 20

Inhibits release of prolactin (dopamine also called PIF)

Question 21

What metabolizes dopamine?

Answer 21

MAO and COMT (just like NE)

Question 22

What receptors can dopamine bind to?

Answer 22

D1 -- increases cAMP (excitatory/activation) D2 -- decreases cAMP (inhibitory)

Question 23

What does dopamine control?

Answer 23

Motor integration/control (loss of dopamine associated with Parkinsonism) THINK: dopamine and dexterity both start with d Limbic subcortical projections controlling reward, punishment, etc. (dysfunction associated with schizophrenia and addiction)

Question 24

What is the most abundant excitatory NT in the brain and spinal cord?

Answer 24

Glutamate

Question 25

_____ cells can convert glutamate into less potent glutamine

Answer 25

Glial cells (most specifically astrocytes)

Question 26

What situations cause an overabundance of glutamate?

Answer 26

Ischemia/anoxia, trauma, hypoglycemia Damage to neurons and glial cells (failure to reuptake or convert)

Question 27

What receptors can glutamate bind to?

Answer 27

NMDA -- ionophores that open Ca channels and allow Na influx Kainate and AMPA -- ionophores that primarily allow Na+ influx, but also allow some K+ efflux (net effect is a decrease in EN and depolarization)

Question 28

What is the classic inhibitory NT?

Answer 28

GABA

Question 29

How is GABA made?

Answer 29

Synthesized from glutamate via glutamate decarboxylase (GAD)

Question 30

What receptors does GABA bind?

Answer 30

GABA(A) -- ionophore that increases chloride entry, making it INHIBITORY * this is the MOA of benzodiazepines GABA(B) -- ionophore that increases K+ exit and delays the opening of Ca2+ channels, making it INHIBITORY

Question 31

Is glycine an excitatory or inhibitory NT?

Answer 31

Mostly inhibitory -- it increases Cl- entry

Question 32

In what situations could glycine be excitatory?

Answer 32

When glycine and glutamate act in tandem, they can bind to NDMA receptors and potentiate the effects of glutamate