1|Page
NROS 418 EXAM 2 (ACTUAL 2025/2026) QUESTIONS
WITH VERIFIED CORRECT ANSWERS
Where do the cholinergic neuromodulator system, serotonin and norepinephrine
neuromodulator systems arise from? - (answer)The neurotransmitter
Norepinephrine is released by the Locus Coeruleus
The neurotransmitter Serotonin is released from the Raphe Nuclei
Picture
What do we mean when we say the SCN has a core and shell region? List the
major inputs and outputs of the core and shell regions. - (answer)The core of the
SCN receives light input from the retina and sends out projections to the shell
region. The shell sends output projections and diffuse signals into peripheral
areas such as the fore brain, hypothalamus, and thalamic nuclei, pre-optic area,
raphe nuclei, and locus coeruleus. You can differentiate the shell and core regions
by the type of cells that are represented (VIP for the core and AVP for the shell).
Picture
What is the location and function of hypocretin neurons? - (answer)Hypocretin,
also known as Orexin, is a neuropeptide that regulates arousal, wakefulness, and
appetite. Orexinergic neurons in the lateral hypothalamic group are closely
associated with reward related functions, such as conditioned place preference.
These neurons preferentially innervate the ventral tegmental area and the
ventromedial prefrontal cortex. In contrast to the lateral hypothalamic neurons,
the perifornical-dorsal group of orexinergic neurons involved in functions related
to arousal and autonomic response. These neurons project inter-
hypothalamically, as well as to the brainstem, where the release of orexin
modulates various autonomic processes
,2|Page
What are the targets of the ventro-lateral pre-optic area neurons? -
(answer)picture
What is meant by diffuse modulatory systems? List the four major systems
(provide diagrams) and compare their source location, their projections and their
common features. - (answer)Diffuse modulatory systems are where there are
multiple axonal projections and diffuse into other cells. The four major pathways
and their common features are, simple diffusion (autocrine and paracrine), vector
(endocrine like), Nerve bundle association, and perivascular space association
which are both diffusion pathways.
LOCATION?(first lecture)
What is an axonal varicosity - provide a diagram. Compare point-to-point and
diffuse modulatory transmission. - (answer)Point to point is when the action
potentials are released across the synapse and bind to the postsynaptic receptors
that are temporally and spatially accurate whereas diffuse modulatory
transmission has divergent axonal projections that communicate with other
neurons.
What behaviors are typically associated with activation of each of the 4 major
neuromodulatory systems? - (answer)Typical behaviors involved with these
systems have to do with the neurotransmitters that are targeted. For example,
dopaminergic would result in behaviors of happiness whereas noradrenergic
would result in behaviors like how easily you are aroused.
Lecture for other 3
, 3|Page
Several neuromodulatory systems are involved in initiating/maintaining an awake
state. Draw one of these systems on a sagittal (side) view of the brain at the
midline. If you gave a drug that partially blocked the receptors for these
neuromodulators, what might the effect be on the sleep-wake cycle? Explain the
underlying physiology. - (answer)The noradrenaline system is involved in
sleep/wake cycles and other things. If a drug was given to partially block and
make the system unable to work it would result in the person's inability to
continue to stay awake and be in a constant state of fatigue. The physiology
behind this is the fact that the locus coeruleus would be affected at most which is
one of the main areas with arousal and attention.
-similar to others like dopamine, check lecture
Why might there be multiple side effects related to use of drugs that affect the
neuromodulatory systems themselves or their receptors? -
(answer)Neuromodulators are extremely diverse in their target cells, target
specificity, and most importantly in their function. Because these molecules serve
a wide variety of roles, altering them through drugs is likely to cause multiple
unintended effects.
Why are circadian rhythms important for animal adaptation to the environment.
Include both daily and seasonal considerations. - (answer)Circadian rhythms are
important for behaviors to take place at the most opportunistic times of day
How is a circadian rhythm generated and how are the circuits entrained by light in
the SCN? Be able to outline the pathways involved and explain the role of rods
and cones vs ipRGCs. What experiments were done to show ipRGC involvement? -
NROS 418 EXAM 2 (ACTUAL 2025/2026) QUESTIONS
WITH VERIFIED CORRECT ANSWERS
Where do the cholinergic neuromodulator system, serotonin and norepinephrine
neuromodulator systems arise from? - (answer)The neurotransmitter
Norepinephrine is released by the Locus Coeruleus
The neurotransmitter Serotonin is released from the Raphe Nuclei
Picture
What do we mean when we say the SCN has a core and shell region? List the
major inputs and outputs of the core and shell regions. - (answer)The core of the
SCN receives light input from the retina and sends out projections to the shell
region. The shell sends output projections and diffuse signals into peripheral
areas such as the fore brain, hypothalamus, and thalamic nuclei, pre-optic area,
raphe nuclei, and locus coeruleus. You can differentiate the shell and core regions
by the type of cells that are represented (VIP for the core and AVP for the shell).
Picture
What is the location and function of hypocretin neurons? - (answer)Hypocretin,
also known as Orexin, is a neuropeptide that regulates arousal, wakefulness, and
appetite. Orexinergic neurons in the lateral hypothalamic group are closely
associated with reward related functions, such as conditioned place preference.
These neurons preferentially innervate the ventral tegmental area and the
ventromedial prefrontal cortex. In contrast to the lateral hypothalamic neurons,
the perifornical-dorsal group of orexinergic neurons involved in functions related
to arousal and autonomic response. These neurons project inter-
hypothalamically, as well as to the brainstem, where the release of orexin
modulates various autonomic processes
,2|Page
What are the targets of the ventro-lateral pre-optic area neurons? -
(answer)picture
What is meant by diffuse modulatory systems? List the four major systems
(provide diagrams) and compare their source location, their projections and their
common features. - (answer)Diffuse modulatory systems are where there are
multiple axonal projections and diffuse into other cells. The four major pathways
and their common features are, simple diffusion (autocrine and paracrine), vector
(endocrine like), Nerve bundle association, and perivascular space association
which are both diffusion pathways.
LOCATION?(first lecture)
What is an axonal varicosity - provide a diagram. Compare point-to-point and
diffuse modulatory transmission. - (answer)Point to point is when the action
potentials are released across the synapse and bind to the postsynaptic receptors
that are temporally and spatially accurate whereas diffuse modulatory
transmission has divergent axonal projections that communicate with other
neurons.
What behaviors are typically associated with activation of each of the 4 major
neuromodulatory systems? - (answer)Typical behaviors involved with these
systems have to do with the neurotransmitters that are targeted. For example,
dopaminergic would result in behaviors of happiness whereas noradrenergic
would result in behaviors like how easily you are aroused.
Lecture for other 3
, 3|Page
Several neuromodulatory systems are involved in initiating/maintaining an awake
state. Draw one of these systems on a sagittal (side) view of the brain at the
midline. If you gave a drug that partially blocked the receptors for these
neuromodulators, what might the effect be on the sleep-wake cycle? Explain the
underlying physiology. - (answer)The noradrenaline system is involved in
sleep/wake cycles and other things. If a drug was given to partially block and
make the system unable to work it would result in the person's inability to
continue to stay awake and be in a constant state of fatigue. The physiology
behind this is the fact that the locus coeruleus would be affected at most which is
one of the main areas with arousal and attention.
-similar to others like dopamine, check lecture
Why might there be multiple side effects related to use of drugs that affect the
neuromodulatory systems themselves or their receptors? -
(answer)Neuromodulators are extremely diverse in their target cells, target
specificity, and most importantly in their function. Because these molecules serve
a wide variety of roles, altering them through drugs is likely to cause multiple
unintended effects.
Why are circadian rhythms important for animal adaptation to the environment.
Include both daily and seasonal considerations. - (answer)Circadian rhythms are
important for behaviors to take place at the most opportunistic times of day
How is a circadian rhythm generated and how are the circuits entrained by light in
the SCN? Be able to outline the pathways involved and explain the role of rods
and cones vs ipRGCs. What experiments were done to show ipRGC involvement? -
