Hemisphere and region - specific effects of chronic stress in the rat prefrontal cortex

Hemisphärische und Region - spezifische Effekte von chronischen Stress im präfrontalen Kortex der Ratte

von Claudia Perez-Cruz
Dissertation
Datum der mündl. Prüfung:2007-04-18
Erschienen:2007-05-03
Betreuer:Prof. Dr. Eberhard Fuchs
Gutachter:Prof. Dr. Reiner Kirchheim
Gutachter:PD Dr. Anastassia Stoykova
Gutachter:Prof. Dr. Ralf Heinrich
Zum Verlinken/Zitieren: http://dx.doi.org/10.53846/goediss-3301

 

 

Dateien

Name:perez-cruz.pdf
Size:20.2Mb
Format:PDF
Description:Dissertation

Lizenzbestimmungen:

Zusammenfassung

Englisch

This thesis demonstrated that pyramidal neurons of the prelimbic and infralimbic area of the rat prefrontal cortex had an intrinsic morphological asymmetry in that pyramidal neurons in the right hemisphere presented longer apical dendrites compared to the left. Stress induced-morphological alterations in pyramidal neurons were regionand hemispheric dependent, resulting in a final loss of hemisphere lateralization. Stressinduced retraction of apical dendrites in right infralimbic and prelimbic areas; however in anterior cingulated cortex apical dendrites were retracted in the left hemisphere. In addition, stress causes retraction of basal dendrites proximal to soma in the prelimbic area with concomitant reduction in spine density. Furthermore, the right prelimbic area showed reductions in apical dendrites after intraperitoneal injections of vehicle, demonstrating that this sub-area of the prefrontal cortex is highly sensitive to stress. The effects of diurnal cycle and stress on spine densities in basal dendrites were also investigated. Surprisingly, control rats presented a diurnal variation in the number of spines in the left hemisphere. Chronic stress shifted this circadian variation to the right hemisphere. These alterations were selectively localized in proximal basal dendrites. The effectiveness of an antidepressant, tianeptine, to abolish the dendritic remodeling caused by stress was evaluated. The drug did not restore the morphological changes induced by stress; however, physiological alterations induced by stress were successfully blocked by tianeptine. It is hypothesized that these morphological remodeling of pyramidal neurons in the prefrontal cortex may have an important regulatory function in stress responses and might be part of an adaptive strategy to cope with stressful situations. This study offers important information to the field of stress research, as it is the first description of a region- and hemisphere- specific effects of stress in the rat prefrontal cortex.
Keywords: Prefrontal cortex stress pyramidal neurons
Schlagwörter: Präfrontaler Kortex Stress Pyramiden Neurone
 
Statistik