Neuro Pharm I

Question 1

What are the 4 features of a neurotransmitter?

Answer 1

1. synthesized in the neuron
2. present in the presynaptic terminal and released in amounts suffienct to cause the postulated rxn in the post-synaptic cell
3. cause the same effects when applied exogenously
4. a mechanism exists for their removal from the synapse

Question 2

What is one principle about a given neuron and neurotransmitter?

Answer 2

generally, neurons make use of the same transmitter(s) at all of the synapses- but a neuron can use many different transmitters

Question 3

What are some features of small molecule transmitters?

Answer 3

often made by enzymes in presynaptic terminals
reuptake is the major mechanism of inactivation, and the molecule may be recycled
often released with cotransmitters, like Zn, that have an important impact on their activity

Question 4

What are some features of neuroactive peptides?

Answer 4

made by protein-making machinery: DNA to mRNA to processed protein in ER and Golgi
made in the cell body and transported to the synapse by fast axonal transport
often released with cotransmitters

Question 5

What are examples of neurotransmitters that don’t fit the usual categories? How do they differ?

Answer 5

Nitric oxide, eicosanoids, adenosine
don't use vesicles
adenosine made in the synapses
NO and eicosanoids made in the presynaptic terminal and diffuse across membranes
synthesized on demand

Question 6

How is ACh produced (ingredients and enzyme)? Where in the cell is it produced?

Answer 6

choline acetyltransferase acts on choline and acetyl Co-A in the nerve terminal

Question 7

What is a main difference between nicotinic and muscarinic receptors in terms of receptor type?

Answer 7

nicotinic receptors are ligand gated ion channels

muscarinic receptors are G-protein coupled receptors

Question 8

What are some examples of central cholinergic pathways? What do they do? (3)

Answer 8

cell bodies in the ventral forebrain involved in cortical activation and memory processing
cell bodies in the brainstem tegumentum (midbrain and pons) that innervate the hypothalamus and thalamus and are involved in thalamocortiacl centers needed for arousal and REM sleep
short interneurons in the striatum that participate in control of movement

Question 9

What 4 conditions do I need to know for this exam that have to do with cholinergic pathways or receptors? Drugs?

Answer 9

mysthenia gravis: AChE inhib
Alzheimers (donepizil): AChE inhib
PD (atropine, a muscarinic blocker, used as treatment)
dystonia (abdormal muscle contraction):botulinum toxin

Question 10

What should I know about catecholamine synthesis?

Answer 10

tyrosine is starter material
tyrosine hydroxylase (rate limiting enzyme) converted to DOPA by AADC (amino acid decarboxylase)
DOPA to dopamine
NE from dopamine in some cells
Epi from NE in some cells (brain and adrenal medulla)

Question 11

What should I know about catecolamine degradation and inactivation?

Answer 11

inactivated by reuptake

degraded by MAO (monoamine oxidase) and COMT(catechol-O-methyltransferase)

Question 12

What are the 3-4 types of dopaminergic neurons?

Answer 12

1. Interneurons with short axons in peripheral autonomic ganglia and retina and olfactory bulb
2. Intermediate length axons in the tuberoinfudibular area and lateral hypothalamus
3. Neurons in the midbrain tegmentum and substantia nigra with long axonal projections.

Question 13

What is an important function of short axon dopaminergic interneurons?

Answer 13

modfy sensory input by inhibiting target neurons in peripheral autonomic ganglia and retian and olfactory bulb. This is an important early step in visual imaging processing.

Question 14

What are important functions of intermediate-length dopaminergic neurons? Clinical relevance (side effects and as drugs)

Answer 14

found in the tuberoinfundibular area and lateral hypothalamus. tuberoinfundibular neurons are responsible for inhibition of prolactin production by anterior pituitary (antipsychotics often cause galactorrhea). In this case DAt behaves as a neurochrome instead of a neurotransmitter because it reaches the pituitary via portal vasculature, not cleft. Some pituitary tumors can be treated with DA analogs.

Question 15

What are the functions of the dopaminergic neurons of the ventral tegumentum?

Answer 15

project to limbic system. in nucleus accuumbens, DA generates positive reinforcing feelings: important for addiction.
Cocaine blocks DA reuptake; amphetamines stimulate DA release.

Question 16

What kinds of receptors are dopamine receptors? What types should I know?

Answer 16

all G-protein coupled
D1 and D5 have lower DA affinity and binding activates adenylyl cylase and incr. cAMP production
D2-4 inhibit adenylyl cylcase and cAMP.
D2 responsible for inhib of sympathetic ganglion activity, inhib of prolactin secretion, and inhib of ACh release from striatum

Question 17

Where are NE neurons found centrally? What are their general functions?

Answer 17

found in the lateral tegumental nuclei of the pons and medulla, and in the locus ceruleus of the dorsal pons. NE neurons help control responses to external and internal stimuli. Lateral tegmental projections help activate the symapthetic system. Locus ceruleus helps with arousal and attention.

Question 18

Where are central epineprhine containing neruons located? Where do they send projections? function in CNS?

Answer 18

lateral and dorsal tegmental nuclei in the brain stem. send projections to the hypothalamus, locus ceruleus, and intermediolateral cell column
function: hypothalamic and autonomic regulation

Question 19

From where is epinephrine released in the periphery?

Answer 19

chromaffin cells in the adrenal medulla

Question 20

What should I know about terminals of NE and Epi neurons?

Answer 20

unique- not discrete synapses, but boutons all along the length of the axon. helps bathe the postynaptic targets with transmitter

Question 21

What should I know about receptors of adrenergic neurons?

Answer 21

alpha 1: incr. PLC, incr. Ca, activate PKC
alpha 2: decr. cAMP: inhibitory
Beta adrenergic receptors: incr. cAMP