Intro to CNS pharmacology

Question 1

Serotoninergic axons originate in the _____ nuclei and innervate most regions of the CNS

Answer 1

raphe

Question 2

Serotonin acts via _____ channels and _____ receptors

Answer 2

ion channels, G protein coupled receptors

Question 3

True or false: serotonin is an excitatory neurotransmitter

Answer 3

False: Excitatory or inhibitory depending on receptor subtype

Question 4

Serotonin was originally discovered as a ____ substance

Answer 4

vasoactive

Question 5

The psychedelic effects of LSD are due to-

Answer 5

Antagonistic effect on serotonin in the brain

Question 6

List four dopaminergic pathways

Answer 6

substantia nigra to caudate-putamen
ventral tegmentum to mesolimbic forebrain
ventral tegmentum to frontal cortex
tuberoinfundibular system (innervates pituitary gland)

Question 7

Describe dopamine receptors

Answer 7

Cell responses via five G protein-coupled receptor subtypes. D1 and D5 activate adenylyl cyclase; D2 (2 isoforms), D3, and D4 inhibit adenylyl cyclase

Question 8

Norepinephrine pathways originate in the ____ and the ____ nuclei

Answer 8

locus coeruleus (to to the frontal cortex, thalamus, hypothalamus, limbic system, and cerebellum) and caudal raphe (to amygdala, midbrain)

Question 9

Histamine pathways originate in the

Answer 9

tuberomamillary nucleus

Question 10

Describe histamine receptors

Answer 10

H1: acts via Gaq, activation is excitatory at neuronal membranes
H2: acts via Gas, activation is usually excitatory or potentiates excitation
H3: autoreceptors; negative feedback to inhibit histamine biosynthesis and release

Question 11

Describe effects of histamine in the brain

Answer 11

arousal, analgesia, locomotion, learning, memory

Question 12

The major excitatory neurotransmitter of the CNS is

Answer 12

glutamate

Question 13

List three glutamate pathways

Answer 13

Cortico-cortical pathways
Pathways between the thalamus and the cortex
Extrapyramidal pathway (projections between the cortex and striatum)

Question 14

Glutamate acts by ____ channels and ____ receptors

Answer 14

ion channels (ex NMDA, AMPA), G coupled protein receptors

Question 15

___ is the major inhibitory neurotransmitter in the CNS

Answer 15

GABA

Question 16

Describe the effects of glycine

Answer 16

inhibitory ion channel, increased Cl influx

Question 17

Describe acetylcholine receptors and their effects

Answer 17

M1 (Gq) receptors are excitatory via ↓ K+ conductance, ↑ IP3 and DAG production

M2 (Gi) receptors are inhibitory via ↑ K+ conductance, ↓ cAMP production

Question 18

Describe the structure of nicotinic receptors in the CNS

Answer 18

excitatory, pentameric ion channels (most common form is a4B2)

Question 19

List other substances that act as neurotransmitters in the CNS

Answer 19

peptides: cholesystokinin, oxytocin, vasopressin, neuropeptide y, opioids, orexin, substance P
others- NO, CO, adenosine, tryptamine, arachidonic acid derivatives

Question 20

List the major categories in the modern classification of CNS drugs

Answer 20

Psychopharmacological agents (antidepressants, antipsychotics, cannabinoids, psychadelics, mood stabilizers)
Antiseizure drugs
Opioids
Anesthetic agents
Drugs for neurodegenerative disease