Introduction To Cns: Pharmacology Block I

Front 1

Describe the anatomic basis of the blood-brain barrier.

Back 1

tight junctions between endothelia cells in the capillaries in the brain. no evidence of such a barrier in the PNS.

Front 2

Describe the movement of ion fluxes in a neuron during the propagation of an action potential.

Back 2

At rest: Na and Cl pumped OUT, K pumped IN
Membrane Depolarization: Na channel opens, Na pumped IN
Repolarization: K channel opens, Na pumped OUT, membrane potential hyperpolarizes.

Front 3

What are the two families of ion channels and what types of drugs target them?

Back 3

1) voltage-gated channels - open in response to transmembrane potential, propagate action potentials, are the target of anti-seizure drugs.
2)Ligand-gated channels: open in response to binding of a chemical messanger, are the target of most drugs that act in the CNS.

Front 4

Where are the cell bodies of norepinephrine receptors found and where do they project to?

Back 4

Pons (locus ceruleus) and midbrain, project to almost all regions of cerebral cortex and limbic system.

Front 5

What's the difference between a1b1 and a2b2 norepinephrine receptors?

Back 5

a1b1: are excitatory, decrease the rectify K conductance
a2b2: are inhibitory, increase the rectifying K conductance

Front 6

Is there only one type of K channel in a neuron?

Back 6

No, there is a separate K leak channel that lets K transiently leave the cell, this is the rectifying channel because it brings the membrane potential back to normal after the action potential.

Front 7

What happens to neurotransmitter concentration targeted by antidepressants?

Back 7

NE channels are in the LIMBIC system, INCREASE the amount of NE in the synapse and DECREASE the amount of postsynaptic B receptor.

Front 8

Name the 3 dopaminergic pathways of pharmacological importance and what diseases are related to them.

Back 8

1) nigrostriatal (extrapyramidal motor control): Parkinson's disease, MPTP Frozen Man syndrome
2) tuberoinfundibular (neuroendocrine): prolactinoma
3) mesolimbic (emotions, reinforcement): addiction, behavioral disorders

Front 9

What neurotransmitter is invovled in regulating emotions, temperature control and the sleep cycle?

Back 9

Serotonin (5-HT)

Front 10

What type of cholinergic receptors predominate in the CNS?

Back 10

Muscarinic M1 type that slowly close the rectifying K channel causing slow excitation. Are involved in cortical arousal and memory.

Front 11

Would acetylcholine treatment to the striatum benefit Alzheimer's disease patients?

Back 11

No, ACh treatment for the basal forebrain and cortex helps Alzheimer's disease. Cholinergic treatment for interneurons in the striatum is for Parkinson's disease.

Front 12

Name three types of amino acid neurotransmitters.

Back 12

A) Glycine
B) Gamma-aminobutyric acid (GABA)
C) Glutamate

Front 13

Where is glycine the major inhibitory neurotransmitter?

Back 13

In the spinal cord.

Front 14

What poison blocks glycine receptors?

Back 14

Strychnine

Front 15

Where are GABA receptors found to mediate inhibitory actions of local interneurons?

Back 15

Cerebellum, cerebral cortex and limbic systems. Sedative-hypnotics and barbituates facilitate the action of GABA.

Front 16

Name the two types of glutamate receptors and the drugs that activate them.

Back 16

NMDA and non-NMDA receptors, activated by antipsychotics.

Front 17

What do ketamine and phencyclidine do to NMDA receptors?

Back 17

They block the NMDA receptor, which is generally excitatory and widespread in the CNS. They are tranquilizing/anesthetic agents.

Front 18

Name 3 types of peptide neurotransmitters and their functions.

Back 18

A) Opioid - endorphin and enkephalin drugs, are generally inhibitory.
B) Leptin - synthesize by adipose tissue possibly to induce satiety and increase lipogenesis when they bind to the ventromedial hypothalamus.
C) Endocannabinoids - brain lipids synthesized in response to stimuli from postsynaptic neuron and bind to CB1 receptor to inhibit neurotransmitter release. Activation affects memory, cognition and pain perception.