The neurobiological model of Post-Traumatic Stress Disorder, based upon the neurobiological model of fear-conditioning, states that the amygdala is hyperactivated, while other, inhibiting structures, like the Anterior Cingulate Cortex (ACC), are hypoactivated, therefore not fully inhibiting the amygdala. Two structural neuroimaging studies have examined the ACC volume to try to comprehend the hypoactivation of the ACC observed in subjects suffering from PTSD. Yamasue et al. (2003) found a lower grey matter density in the ACC of subjects with PTSD. Rauch et al. (2003) found a lower volume of the affective division of the ACC in subjects with PTSD compared to subjects exposed to trauma who did not suffer from PTSD. Comparing 14 subjects with Acute PTSD to 14 healthy control subjects, we replicated the results of Yamasue et al. (2003), but failed to observe any volumetric differences. Further analyses allowed us to be the first study to show that the nature of the difference observed in grey matter density was a shape difference of the ACC. Thus ACC volume does not seem to be related to Acute PTSD. Furthermore, this difference in shape raises questions as to the validity of the results of functional neuroimaging studies and of the neurobiological model of PTSD.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.82209 |
| Date | January 2004 |
| Creators | Corbo, Vincent |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Psychiatry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002198728, proquestno: AAIMR12420, Theses scanned by UMI/ProQuest. |
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