Bryan L. Bodie died prior to submission of this manuscript. The surviving authors dedicate this work to his memory.
The medial prefrontal cortex differentially regulates stress-induced c-fos expression in the forebrain depending on type of stressor
Article first published online: 22 OCT 2003
European Journal of Neuroscience
Volume 18, Issue 8, pages 2357–2364, October 2003
How to Cite
Figueiredo, H. F., Bruestle, A., Bodie, B., Dolgas, C. M. and Herman, J. P. (2003), The medial prefrontal cortex differentially regulates stress-induced c-fos expression in the forebrain depending on type of stressor. European Journal of Neuroscience, 18: 2357–2364. doi: 10.1046/j.1460-9568.2003.02932.x
- Issue published online: 22 OCT 2003
- Article first published online: 22 OCT 2003
- Received 18 March 2003, revised 29 June 2003, accepted 22 July 2003
- ether stress;
- hypothalamo-pituitary-adrenocortical axis;
- medial amygdaloid nucleus;
- paraventricular nucleus;
- restraint stress
The medial prefrontal cortex (mPFC) plays an important inhibitory role in the hypothalamic-pituitary-adrenal (HPA) axis response. The involvement of the mPFC appears to depend on the type of stressor, preferentially affecting ‘psychogenic’ stimuli. In this study, we mapped expression of c-fos mRNA to assess the neural circuitry underlying stressor-specific actions of the mPFC on HPA reactivity. Thus, groups of mPFC-lesioned and sham-operated rats were restrained for 20 min or exposed to ether fumes for 2 min. In both cases, the animals were killed at 40 min from the onset of stress. Interestingly, bilateral lesions of the mPFC significantly enhanced c-fos mRNA expression in the hypothalamic paraventricular nucleus of restrained animals, an effect that was paralleled by potentiation of circulating ACTH concentrations in these animals. On the other hand, lesions of the mPFC did not affect neither PVN c-fos mRNA expression nor plasma ACTH concentrations in animals exposed to ether. Lesions of the mPFC also enhanced c-fos activation in the medial amygdala following restraint, but not following ether exposure. Additional regions whose activity was affected by mPFC lesions or stressor differences included the ventrolateral division of the bed nucleus of the stria terminalis, CA3 hippocampus, piriform cortex, and dorsal endopiriform nucleus. Expression of c-fos mRNA was nearly absent in the central amygdala of all stressed animals, regardless of lesion. Furthermore, prefrontal cortex lesions did not change stress-induction levels of c-fos in the CA1 hippocampus, dentate gyrus, anteromedial division of the bed nucleus of the stria terminalis, lateral septum, and claustrum. Taken together, this study indicates that the medial prefrontal cortex differentially regulates cellular activation of specific stress-related brain regions, thus exerting stressor-dependent inhibition of the HPA axis.