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Old 02-19-2011
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Arrow Test your knowledge #16! (Neuroanatomy)

A 50-year-old male presents with a chief complaint of sleep disturbance. A more detailed history reveals a diminished sense of smell. A disease that affects the neurons controlling intentional movement is suspected. These neurons originate in the ___________ and produce the neurotransmitter ____________ .
  1. Basal nucleus of Meynert, acetylcholine
  2. Locus ceruleus, norepinephrine
  3. Raphe nuclei, serotonin
  4. Substantia nigra, dopamine
  5. Tuberomamillary nucleus, histamine
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Quote:
Originally Posted by Mondoshawan View Post
A 50-year-old male presents with a chief complaint of sleep disturbance. A more detailed history reveals a diminished sense of smell. A disease that affects the neurons controlling intentional movement is suspected. These neurons originate in the ___________ and produce the neurotransmitter ____________ .
  1. Basal nucleus of Meynert, acetylcholine
  2. Locus ceruleus, norepinephrine
  3. Raphe nuclei, serotonin
  4. Substantia nigra, dopamine
  5. Tuberomamillary nucleus, histamine
"A disease that affects the neurons controlling intentional movement is suspected" Totally gives the answer away!

Dz being Parkinsons.

Answer:

D) Substantia Nigra, Dopamine.

Although this is tricky because Parkinson's is defined as imbalance of Dopamine decreasing, and ACh increasing, so it could also be A. HMMM
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Quote:
Originally Posted by mondoshawan View Post
a 50-year-old male presents with a chief complaint of sleep disturbance. A more detailed history reveals a diminished sense of smell. A disease that affects the neurons controlling intentional movement is suspected. These neurons originate in the ___________ and produce the neurotransmitter ____________ .
  1. basal nucleus of meynert, acetylcholine
  2. locus ceruleus, norepinephrine
  3. raphe nuclei, serotonin
  4. substantia nigra, dopamine
  5. tuberomamillary nucleus, histamine
i got to d.
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I dun know... but I'm falling towards B.
Confused between A or B... but then leaning more towards B!!!
It could be D but the sleep disturbance is throwing me off as Ach and NE are needed for sleep and I have a feeling that the diminished sense of smell has somthing to do with these 2 neurotransmitters.
But of course, I can be wrong. Might be making this easy question difficult!
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I'd go with A,
Acetylcholine is needed for olfactory memory (not quite sure mechanisms, know it is also released upon smelling food)
Also Acetylcholine induces sleep (NE inhibits REM sleep)
I don't think substantia nigra has any involvement in smell...
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Arrow B) Locus ceruleus, norepinephrine

My ans is B) Locus ceruleus, norepinephrine

Locus coeruleus is a relatively small nucleus that is found on both sides of the upper pons about 1/3 of the distance between the medulla oblongata and the midbrain. Locus ceruleus produces norepinephrine neurotransmitter.

Locus ceruleus - norepinephrine system is involved in regulation of sleep and wake cycle. In particularly, Locus ceruleus activation promotes wakefulness. Therefore the pt often complains sleep disturbance.

The locus coeruleus is responsible for mediating many of the sympathetic effects during stress. The locus coeruleus is activated by stress, and will respond by increasing norepinephrine secretion, which in turn will increase motor function. This explains the control of intentional movement.

Correct me if I'm wrong...
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Search Hmmmmm

patelMD and wasify81 are right - The disease is Parkinsonís, and the correct answer is D. Substantia nigra, dopamine. The neurons described in (A) widely innervate the cerebral cortex and control alertness. Those in (B) widely innervate the cerebral cortex and cerebellum and maintain vigilance and responsiveness to unexpected stimulus. Those in (C) modulate perception of pain and responsiveness of cortical neurons; together with (B), they are part of the reticular activating system, responsible for consciousness. The neurons described in (E) are responsible for forebrain arousal and are involved in circadian rhythm. The answer was in the wording, as patelMD pointed out. (A) through (E) are all single-source neuronal systems affected to some degree in Alzheimerís, Parkinsonís, or both. Parkinson's patients can present with sleep disturbance, and the loss of olfaction can be a heralding symptom as well - these pointed toward the diagnosis, but the question in this case specifically was asking about "neurons controlling intentional movement".
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Originally Posted by aktorque View Post
My ans is B) Locus ceruleus, norepinephrine

Locus coeruleus is a relatively small nucleus that is found on both sides of the upper pons about 1/3 of the distance between the medulla oblongata and the midbrain. Locus ceruleus produces norepinephrine neurotransmitter.

Locus ceruleus - norepinephrine system is involved in regulation of sleep and wake cycle. In particularly, Locus ceruleus activation promotes wakefulness. Therefore the pt often complains sleep disturbance.

The locus coeruleus is responsible for mediating many of the sympathetic effects during stress. The locus coeruleus is activated by stress, and will respond by increasing norepinephrine secretion, which in turn will increase motor function. This explains the control of intentional movement.

Correct me if I'm wrong...
You may be too smart for your own good, aktorque! I think you overthought this one Or rather, let the answer choices influence your thinking... I think that your explanation is right up until you make the connection between norepinephrine and intentional movement. Neuroanatomy is not my strongest subject, so you could be right, but I don't see the connection?
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Frm d History of d patient,the answer D(substantia Nigra-Dopamine).check d statement frm history dt says "A disease dt affect d intentional movement is Suspected"which means is Parkinson Disease.Disorders of Substantia nigra is called intension tremor while dt of Cerebellum has to with Waddling gait.
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i think answer is D
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Quote:
Originally Posted by AHMED BABATUNDE View Post
Frm d History of d patient,the answer D(substantia Nigra-Dopamine).check d statement frm history dt says "A disease dt affect d intentional movement is Suspected"which means is Parkinson Disease.Disorders of Substantia nigra is called intension tremor while dt of Cerebellum has to with Waddling gait.
You don't see intention tremor in Parkinson's disease... you see resting tremor - look here

Resting Tremor: This tremor occurs when muscles are at rest, making an arm or a leg shake even when a person is completely relaxed. The tremor becomes less noticeable or disappears when the person moves the affected muscles. Resting tremors are often slow and coarse.

These tremors develop when collections of nerve cells at the base of the cerebrum (including the basal ganglia) are disturbed. Such disturbances usually result from Parkinson's disease. Antipsychotic drugs are another common cause of resting tremors.

Resting tremors may be socially embarrassing but typically do not interfere with daily activities, such as drinking a glass of water.

Intention Tremor: This tremor occurs when a person ends a purposeful movement (such as pressing a button) or aims for a target (as when reaching for an object with the hand). The person may miss the targeted object because of the tremor. Intention tremors are relatively slow and coarse.

These tremors may result from damage to the cerebellum or its connections. Thus, cerebellar tremors and intention tremors may be used synonymously. Multiple sclerosis is a common cause. Stroke, Wilson's disease, alcoholism, and overuse of sedatives or anticonvulsants can cause the cerebellum to malfunction, resulting in an intention tremor.
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Originally Posted by Mondoshawan View Post
patelMD and wasify81 are right - The disease is Parkinson’s, and the correct answer ....... but the question in this case specifically was asking about "neurons controlling intentional movement".
are you sure if you lesion the substantia nigra will affect the intentional movement!!! I thought it mainly affects the initiation of the motor activity.

ref:http://bodyandhealth.canada.com/chan...ation_id=10865
"Slowed movement is another symptom of Parkinson's disease. People may also experience trouble starting movement (e.g., starting to walk) and will move much slower than normal. When balance reflexes become impaired, it makes it difficult to turn quickly or negotiate narrow corners and doorways."
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Originally Posted by aktorque View Post
are you sure if you lesion the substantia nigra will affect the intentional movement!!! I thought it mainly affects the initiation of the motor activity.

ref:http://bodyandhealth.canada.com/chan...ation_id=10865
"Slowed movement is another symptom of Parkinson's disease. People may also experience trouble starting movement (e.g., starting to walk) and will move much slower than normal. When balance reflexes become impaired, it makes it difficult to turn quickly or negotiate narrow corners and doorways."
You're right - I should have used "modulate" rather than "control". Sorry - bad wording -> weak question!
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That's alright man... I admire your talent and knowledge to attempt to write such a hard qn. The qns you have posted on this forum are really challenging and made me think hard. I believe that doing your qns make others including me help to recall stuff that we've learned in med school. Thank you and Keep up the good work.
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