Question 1

One similarity between extrasynaptic transmission and synaptic transmission is that

Accepted Answer

A)  both occur with a time lag of seconds to tens of seconds. 
B)  in both cases, vesicles are stored and docked adjacent to the cell membrane. 
C)  both may transmit molecules across short or long distances to receptor sites. 
D)  both release signaling molecules from vesicles by exocytosis. 
E)  both can be stimulated by a single action potential in the releasing neuron. 
A)  both occur with a time lag of seconds to tens of seconds. 
B)  in both cases, vesicles are stored and docked adjacent to the cell membrane. 
C)  both may transmit molecules across short or long distances to receptor sites. 
D)  both release signaling molecules from vesicles by exocytosis. 
E)  both can be stimulated by a single action potential in the releasing neuron.

Question 2

Studies of hypothalamic magnocellular neurons have used radioimmunoassay to show that

Accepted Answer

A)  vesicles may travel long distances from release sites to receptor sites. 
B)  magnocellular neurons are able to synthesize and release more than one peptide at once. 
C)  more vesicles are released at cell bodies than at dendrites. 
D)  trains of action potentials are needed to produce exocytosis. 
E)  extrasynaptic transmission uses dense-core, rather than clear, vesicles. 
A)  vesicles may travel long distances from release sites to receptor sites. 
B)  magnocellular neurons are able to synthesize and release more than one peptide at once. 
C)  more vesicles are released at cell bodies than at dendrites. 
D)  trains of action potentials are needed to produce exocytosis. 
E)  extrasynaptic transmission uses dense-core, rather than clear, vesicles.

Question 3

What is the function of Müller cells in the retina?

Accepted Answer

Müller cells are a type of glial cell in

Question 4

Explain how spillover effects contribute to extrasynaptic communication.

Accepted Answer

Spillover effects use neurotransmitters

Question 5

In extrasynaptic communication, glial cells

Accepted Answer

A)  are the only cells capable of extrasynaptic neurotransmitter release. 
B)  work in coordination with neurons, with both capable of extrasynaptic neurotransmitter release. 
C)  provide the physical scaffolding needed for molecules to pass from one neuron to the next. 
D)  help construct a filter to prevent extrasynaptically released molecules from leaving the brain. 
E)  reduce the distance that signals can travel, by repackaging any molecules released outside of synapses. 
A)  are the only cells capable of extrasynaptic neurotransmitter release. 
B)  work in coordination with neurons, with both capable of extrasynaptic neurotransmitter release. 
C)  provide the physical scaffolding needed for molecules to pass from one neuron to the next. 
D)  help construct a filter to prevent extrasynaptically released molecules from leaving the brain. 
E)  reduce the distance that signals can travel, by repackaging any molecules released outside of synapses.

Question 6

The sequence of events by which serotonin produces somatic exocytosis in the leech Retzius neuron can best be characterized as

Accepted Answer

A)  a negative feedback loop. 
B)  a positive feedback loop. 
C)  lateral inhibition. 
D)  a command center. 
E)  a central pattern generator. 
A)  a negative feedback loop. 
B)  a positive feedback loop. 
C)  lateral inhibition. 
D)  a command center. 
E)  a central pattern generator.

Question 7

What signaling molecules are released by magnocellular hypothalamic neurons, and from where are they released?

Accepted Answer

Magnocellular hypothalamic neu

Question 8

A fundamental role of glial cells in extrasynaptic communication is to

Accepted Answer

A)  help transport dense-core vesicles from release sites to receptor sites. 
B)  put the 'brakes' on signaling by absorbing signaling molecules. 
C)  pass along messages by capturing and releasing signaling molecules. 
D)  help form electrical connections between one neuron and the next. 
E)  promote negative feedback by inhibiting neurons that release neurotransmitters. 
A)  help transport dense-core vesicles from release sites to receptor sites. 
B)  put the 'brakes' on signaling by absorbing signaling molecules. 
C)  pass along messages by capturing and releasing signaling molecules. 
D)  help form electrical connections between one neuron and the next. 
E)  promote negative feedback by inhibiting neurons that release neurotransmitters.

Question 9

When measuring intracellular calcium levels of leech Retzius neurons, high-frequency stimulation (e.g. 20 Hz) of the neuron

Accepted Answer

A)  leads to a later, slower peak than low-frequency stimulation. 
B)  produces a jagged, shark-tooth pattern with low peaks. 
C)  leads to a faster, higher peak concentration than low-frequency stimulation. 
D)  produces a gradual, roughly linear increase in concentration. 
E)  has no measurable effect on calcium concentration. 
A)  leads to a later, slower peak than low-frequency stimulation. 
B)  produces a jagged, shark-tooth pattern with low peaks. 
C)  leads to a faster, higher peak concentration than low-frequency stimulation. 
D)  produces a gradual, roughly linear increase in concentration. 
E)  has no measurable effect on calcium concentration.

Question 10

When a Müller cell is stimulated with ATP, this leads to

Accepted Answer

A)  influx of Na+ followed by an action potential. 
B)  the production of IP3 and release of intracellular calcium. 
C)  phosphorylation and inactivation of potassium channels. 
D)  the release of dopamine into the CSF. 
E)  somatic exocytosis. 
A)  influx of Na+ followed by an action potential. 
B)  the production of IP3 and release of intracellular calcium. 
C)  phosphorylation and inactivation of potassium channels. 
D)  the release of dopamine into the CSF. 
E)  somatic exocytosis.

Question 11

Magnocellular hypothalamic neurons release _______ from the axons or dendrites.

Accepted Answer

A)  either oxytocin or vasopressin 
B)  either dopamine or serotonin 
C)  acetylcholine 
D)  either epinephrine or norepinephrine 
E)  glutamate 
A)  either oxytocin or vasopressin 
B)  either dopamine or serotonin 
C)  acetylcholine 
D)  either epinephrine or norepinephrine 
E)  glutamate

Question 12

Which of the options below is not a method of extrasynaptic exocytosis?

Accepted Answer

A)  Somato-dendritic exocytosis 
B)  Axonal exocytosis 
C)  Perisynaptic exocytosis 
D)  Perivascular exocytosis 
E)  Spillover 
A)  Somato-dendritic exocytosis 
B)  Axonal exocytosis 
C)  Perisynaptic exocytosis 
D)  Perivascular exocytosis 
E)  Spillover

Question 13

What are "tripartite synapses" and how are they involved in extrasynaptic communication?

Accepted Answer

"Tripartite synapses" refer to the inclu

Question 14

In magnocellular neurons of the hypothalamus, oxytocin released from dendrites

Accepted Answer

A)  mingles with synaptically released oxytocin to amplify its effects. 
B)  affects calcium release in neighboring neurons without altering electrical activity. 
C)  moves directly into the bloodstream for wide dissemination. 
D)  is sufficient to produce action potentials in neighboring neurons. 
E)  inhibits vesicle fusion at synaptic sites. 
A)  mingles with synaptically released oxytocin to amplify its effects. 
B)  affects calcium release in neighboring neurons without altering electrical activity. 
C)  moves directly into the bloodstream for wide dissemination. 
D)  is sufficient to produce action potentials in neighboring neurons. 
E)  inhibits vesicle fusion at synaptic sites.

Question 15

Describe one method used by researchers to determine where extrasynaptic transmission occurs.

Accepted Answer

One method is to use histology to detect

Question 16

Briefly explain what volume transmission is.

Accepted Answer

Volume transmission occurs when signalin

Question 17

What is the role of L-type calcium channels in the leech Retzius neuron?

Accepted Answer

Calcium is essential to somatic exocytos

Question 18

The main function of the Leech Retzius Neurons is to

Accepted Answer

A)  initiate feeding behavior. 
B)  stimulate release of oxytocin and/or vasopressin. 
C)  synchronize motoneuron activity to command crawling behavior. 
D)  modulate aggressive behaviors. 
E)  inhibit release of octopamine. 
A)  initiate feeding behavior. 
B)  stimulate release of oxytocin and/or vasopressin. 
C)  synchronize motoneuron activity to command crawling behavior. 
D)  modulate aggressive behaviors. 
E)  inhibit release of octopamine.

Exam 18: Mechanisms of Extrasynaptic Communication

One similarity between extrasynaptic transmission and synaptic transmission is that

Studies of hypothalamic magnocellular neurons have used radioimmunoassay to show that

What is the function of Müller cells in the retina?

Explain how spillover effects contribute to extrasynaptic communication.

In extrasynaptic communication, glial cells

The sequence of events by which serotonin produces somatic exocytosis in the leech Retzius neuron can best be characterized as

What signaling molecules are released by magnocellular hypothalamic neurons, and from where are they released?

A fundamental role of glial cells in extrasynaptic communication is to

When measuring intracellular calcium levels of leech Retzius neurons, high-frequency stimulation (e.g. 20 Hz) of the neuron

When a Müller cell is stimulated with ATP, this leads to

Magnocellular hypothalamic neurons release _______ from the axons or dendrites.

Which of the options below is not a method of extrasynaptic exocytosis?

What are "tripartite synapses" and how are they involved in extrasynaptic communication?

In magnocellular neurons of the hypothalamus, oxytocin released from dendrites

Describe one method used by researchers to determine where extrasynaptic transmission occurs.

Briefly explain what volume transmission is.

What is the role of L-type calcium channels in the leech Retzius neuron?

The main function of the Leech Retzius Neurons is to

Principles of Signaling and Organization

Signaling in the Visual System

Functional Architecture of the Visual Cortex

Ion Channels and Signaling

Structure of Ion Channels

Ionic Basis of the Resting Potential

Ionic Basis of the Action Potential

Electrical Signaling in Neurons

Ion Transport Across Cell Membranes

Properties and Functions of Neuroglial Cells

Mechanisms of Direct Synaptic Transmission

Indirect Mechanisms of Synaptic Transmission

Release of Neurotransmitters

Neurotransmitters in the Central Nervous System

Transmitter Synthesis, Storage, Transport, and Inactivation

Synaptic Plasticity

The Molecular and Cellular Biology of Synaptic Plasticity

Autonomic Nervous System

Walking, Flying, and Swimming: Cellular Mechanisms of Sensorimotor Behavior in Invertebrates

Sensory Transduction

Transduction and Transmission in the Retina

Touch, Pain, and Texture Sensation

Auditory and Vestibular Sensation

Constructing Perception

Initiation and Control of Coordinated Muscular Movements

Development of the Nervous System

Critical Periods in Sensory Systems

Regeneration and Repair of Synaptic Connections After Injury

Appendix

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