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Thalamus
and Cerebral Cortex
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on image to enlarge
The lateral
thalamus that receives cardiac information via the spinothalamic
tract includes the ventroposterolateral, ventroposteromedial,
and ventroposteroinferior nuclei. Axons from cells of the lateral
thalamus relay information to the primary somatosensory cortex
and possibly to the secondary somatic cortex. This evidence suggests
that visceral information projects to the somatosensory cortex
(Bruggemann
and Apkarian, 1997; Follett
and Dirks, 1994). Information processed in this cortical area
contributes to sensory discrimination (Melzack
and Wall, 1982; Price
and Dubner, 1977).
Cardiac and
somatic information also project via the spinothalamic and spinoreticular
tracts to the intralaminar thalamic nuclei, primarily to the centralis
lateralis and centrum medianum-parafascicularis nuclei (Boivie,
1979; Mehler,
1960; Craig and Dostrovsky,
1997). The information generated in these nuclei is relayed
to the association cortex including the insular cortex, amygdala
and cingulate gyrus (Bentivoglio
et al., 1981; Berendse
and Groenewegen, 1991; Sadikot
et al., 1990). These nuclei may contribute to the emotional
components of pain including autonomic adaptations (Melzack
and Wall, 1982; Albe-Fessard
and Besson, 1973; Casey and
Jones, 1978; Melzack
and Casey, 1968).
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