Lecture 5 (Revised)

Question 1

Synaptic Transmission?

Answer 1

Translation of signal into a change in postsynaptic Vm

Question 2

(Synaptic Transmission)
Classes of Membrane Receptors?

Answer 2

1) Ionotropic (Ligand-Gated)
-Fast response
2) Metabotropic (GPCR)
-Slow and variable response

Question 3

Ionotropic (Ligand-Gated) Receptors?

Answer 3

-Direct activation of neurotransmitter receptor channel elicits fast PSPs
-Examples:
1) nAChR - Acetylcholine
2) NMDA and AMPA Receptors - Glutamate
3) Serotonin Receptor Channel - 5HT3 (Excitatory)
4) GABA Receptors (Types A and C)
5) Glycine Receptor (GlyR)

Question 4

Metabotropic (G-Protein Coupled) Receptors?

Answer 4

-Activation of G-Protein coupled receptor elicits slow PSPs
-Examples:
1) mAChR
2) mGluR
3) Biogenic Amine Receptors (Serotonin (excluding 5HT3R)) (Dopamine, NE, Histamine)
4) GABA Receptor (Type B)

Question 5

Metabotropic Receptors + 2nd Messenger Pathways?

Answer 5

-Gg activates phospholipase C which results in formation of:
(IP3 –> Increased [Ca2+])
(Diacylglycerol –> activation of PKC)
-Gs activates adenyl cyclase resulting in:
(Increased cAMP –> Increased activity of PKA)
-Gi inhibits adenyl cyclase resulting in:
(Decreased cAMP –> Decreased acuity of PKA)

Question 6

(Metabotropic Receptors + 2nd Messenger Pathways)
Gg?

Answer 6

Gg activates phospholipase C which results in formation of:
(IP3 –> Increased [Ca2+])
(Diacylglycerol –> activation of PKC)

Question 7

(Metabotropic Receptors + 2nd Messenger Pathways)
Gs?

Answer 7

Gs activates adenyl cyclase resulting in:
(Increased cAMP –> Increased activity of PKA)

Question 8

(Metabotropic Receptors + 2nd Messenger Pathways)
Gi?

Answer 8

Gi inhibits adenyl cyclase resulting in:
(Decreased cAMP –> Decreased acuity of PKA)

Question 9

Following neurotransmitter receptor activation, postsynaptic membrane potential (Vm) will always move?

Answer 9

Toward reversal potential of activated neurotransmitter receptor induced conductance
1) EPSP
2) IPSP

Question 10

EPSP postsynaptic potentials that?

Answer 10

Increase probability of causing postsynaptic cell to fire an AP

Question 11

IPSP postsynaptic potentials that?

Answer 11

Decrease probability of causing postsynaptic cell to fire an AP

Question 12

Reversal Potential?

Answer 12

Point at which direction of net current flow reverses and is same as equilibrium potential (almost identical to equilibrium potential)

Question 13

EPSP reversal potential of induced conductance is?

Answer 13

More positive than threshold (will meet threshold so get AP)

Question 14

IPSP reversal potential of induced conductance is?

Answer 14

More negative than threshold (will fire an IPSP) (Hyperpolarization)

Question 15

(Increasing postsynaptic conductance)
Na+?

Answer 15

EPSP

Question 16

(Increasing postsynaptic conductance)
K+?

Answer 16

IPSP

Question 17

(Increasing postsynaptic conductance)
Ca+?

Answer 17

EPSP

Question 18

(Increasing postsynaptic conductance)
Cl-?

Answer 18

IPSP

Question 19

(Increasing postsynaptic conductance)
Na+/K+ equally?

Answer 19

EPSP

Question 20

(Increasing postsynaptic conductance)
Decreasing conductance of K+ produces?

Answer 20

EPSP

Question 20

Convergence of input?

Answer 20

Several neurons synapse onto a single neuron

Question 21

Convergence of output?

Answer 21

Single neuron projects onto several neurons

Question 22

Grand Postsynaptic Potential?

Answer 22

Temporal and spatial summation of all EPSP’s and IPSP’s determines excitability of postsynaptic cell

Question 23

Afferent neurons carry?

Answer 23

Information from sensory receptors to CNS

Question 24

Efferent neurons carry?

Answer 24

Motor information away from CNS to muscles and glands of body

Question 25

Efferent neurons carry?

Answer 25

Motor information away from CNS to muscles and glands of body