Download Functional neuroanatomy of pain

ESSAY TOPICS ON CNS
1. Functional neuroanatomy of pain
Reference
Usunoff, K.G., Popratiloff, A., Schmitt, O., Wree, A. Functional Neuroanatomy of Pain
Series: Advances in Anatomy, Embryology and Cell Biology, Vol. 184, 2006.
Introduction.- Functional neuroanatomy of the pain system.- Primary afferent neuron.Distribution of nociceptor peripheral endings.- Termination in the spinal cord and spinal
trigeminal nucleus.- Ascending pathways of the spinal cord and of the STN.- Dorsal column
nuclei and nociception.- Cerebellum and nociception.- Cortices involved in pain perception
and thalamocortical projection.- Descending modulatory pathways.- Neuropathic pain.Central changes consequent to peripheral nerve injury.- The role of glial cells.Neuropathology of herpes zoster (HZ) and of postherpetic neuralgia (PHN).- Diabetic
neuropathic pain.- Cancer neuropathic pain.- Central neuropathic pain
2. Neuroanatomy of the pain system and of the pathways that modulate pain.
Reference
Willis WD, Westlund KN. Department of Anatomy & Neurosciences, University of Texas
Medical Branch, Galveston 77555-1069, USA.
Abstract
We review many of the recent findings concerning mechanisms and pathways for pain and
its modulation, emphasizing sensitization and the modulation of nociceptors and of dorsal
horn nociceptive neurons. We describe the organization of several ascending nociceptive
pathways, including the spinothalamic, spinomesencephalic, spinoreticular, spinolimbic,
spinocervical, and postsynaptic dorsal column pathways in some detail and discuss
nociceptive processing in the thalamus and cerebral cortex. Structures involved in the
descending analgesia systems, including the periaqueductal gray, locus ceruleus, and
parabrachial area, nucleus raphe magnus, reticular formation, anterior pretectal nucleus,
thalamus and cerebral cortex, and several components of the limbic system are described
and the pathways and neurotransmitters utilized are mentioned. Finally, we speculate on
possible fruitful lines of research that might lead to improvements in therapy for pain.
3. The Compassionate Brain: Humans Detect Intensity of Pain from Another's Face
Reference
Miiamaaria V. Saarela, Yevhen Hlushchuk, Amanda C. de C. Williams, Martin Schürmann,
Eija Kalso and Riitta Hari.
Abstract
Understanding another person's experience draws on "mirroring systems," brain circuitries
shared by the subject's own actions/feelings and by similar states observed in others. Lately,
also the experience of pain has been shown to activate partly the same brain areas in the
subjects‘ own and in the observer's brain. Recent studies show remarkable overlap between
brain areas activated when a subject undergoes painful sensory stimulation and when he/she
observes others suffering from pain. Using functional magnetic resonance imaging, we show
that not only the presence of pain but also the intensity of the observed pain is encoded in
the observer's brain—as occurs during the observer's own pain experience. When subjects
observed pain from the faces of chronic pain patients, activations in bilateral anterior insula
(AI), left anterior cingulate cortex, and left inferior parietal lobe in the observer's brain
correlated with their estimates of the intensity of observed pain. Furthermore, the strengths
of activation in the left AI and left inferior frontal gyrus during observation of intensified pain
correlated with subjects’ self-rated empathy. These findings imply that the intersubjective
representation of pain in the human brain is more detailed than has been previously thought.
4. Somatotopic Activation in the Human Trigeminal Pain Pathway
Reference
Alex F. M. DaSilva, Lino Becerra, Nikos Makris, Andrew M. Strassman, R. Gilberto Gonzalez,
Nina Geatrakis, and David Borsook. The Journal of Neuroscience, September 15, 2002,
22(18):8183-8192
Abstract
Functional magnetic resonance imaging was used to image pain-associated activity in three
levels of the neuraxis: the medullary dorsal horn, thalamus, and primary somatosensory
cortex. In nine subjects, noxious thermal stimuli (46°C) were applied to the facial skin at sites
within the three divisions of the trigeminal nerve (V1, V2, and V3) and also to the ipsilateral
thumb. Anatomical and functional data were acquired to capture activation across the
spinothalamocortical pathway in each individual. Significant activation was observed in the
ipsilateral spinal trigeminal nucleus within the medulla and lower pons in response to at least
one of the three facial stimuli in all applicable data sets. Activation from the three facial
stimulation sites exhibited a somatotopic organization along the longitudinal (rostrocaudal)
axis of the brain stem that was consistent with the classically described "onion skin" pattern
of sensory deficits observed in patients after trigeminal tractotomy. In the thalamus,
activation was observed in the contralateral side involving the ventroposteromedial and
dorsomedial nuclei after stimulation of the face and in the ventroposterolateral and
dorsomedial nuclei after stimulation of the thumb. Activation in the primary somatosensory
cortex displayed a laminar sequence that resembled the trigeminal nucleus, with V2 more
rostral, V1 caudal, and V3 medial, abutting the region of cortical activation observed for the
thumb. These results represent the first simultaneous imaging of pain-associated activation
at three levels of the neuraxis in individual subjects. This approach will be useful for
exploring central correlates of plasticity in models of experimental and clinical pain.
5. Memory, language, and other brain abilities
Brain memory
1. Brain memory
2. How to improve brain memory
3. Brain memory types
o Conscious cognitive processes
 Instantaneous memory
 Specialized memory
 Linguistic
 Visual
 Emotional
o The persistence of brain memory
 Short-term memory
 Medium-term memory
 Long-term memory
 Vital memory
o Reliability of the memory information system
o Data integrity
4. Human brain memory
o Automatic memory and directed memory
o Pre-established logic blocks or structures
o Memorise only what it is not logic
5. Evolutionary genetics and neuroscience
o Brain memory inheritance
o The simple complementary effect
o Genetic foundation and the origin of language
6. Emotions and brain
The amygdala and allies
Reference: www: thebrain.mcgill.ca
Abstract
The amygdala is an almond-shaped structure in the brain; its name comes from the Greek
word for “almond”. As with most other brain structures, you actually have two amygdalae
(shown in red in the drawing here). Each amygdala is located close to the hippocampus, in
the frontal portion of the temporal lobe.
Your amygdalae are essential to your ability to feel certain emotions and to perceive them in
other people. This includes fear and the many changes that it causes in the body. If you are
being followed at night by a suspect-looking individual and your heart is pounding, chances
are that your amygdalae are very active!
In certain studies, researchers have directly stimulated the amygdalae of patients who were
undergoing brain surgery, and asked them to report their impressions. The subjective
experience that these patients reported most often was one of imminent danger and fear. In
studies of the very small number of patients who have had had only their amygdala
destroyed (as the result of a stroke, for example), they recognized the facial expressions of
every emotion except fear.
In fact, the amygdala seems to modulate all of our reactions to events that are very
important for our survival. Events that warn us of imminent danger are therefore very
important stimuli for the amygdala, but so are events that signal the presence of food,
sexual partners, rivals, children in distress, and so on.
That is why the amygdala has so many connections with several other structures in the
brain.