Fos Immunoreactivity in the Diagonal Band and the Perinuclear Zone of the Supraoptic Nucleus after Hypertension and Hypervolaemia in Unanaesthetized Rats

Abstract

We used Fos immunocytochemistry to study the effects of hypertension and hypervolaemia on neurones in the diagonal band of Broca and the perinuclear zone of the supraoptic nucleus, two nuclei that are both involved in the baroreceptor regulation of vasopressin neurones in the supraoptic nucleus. In addition, we used sino-aortic denervation to examine the role of arterial baroreceptors in the response to these haemodynamic changes. Sham-operated and sino-aortic denervated rats were infused with phenylephrine sufficient to increase blood pressure for 2 h. Control rats were infused with the same volume of isontonic saline. Only Sham sino-aortic denervated rats showed reflex bradycardia in response to the increased blood pressure. Volume expansion was produced by infusing the rats with isotonic saline equal to 10% of their body weight for 10 min, which significantly increased central venous pressure. In the diagonal band of Broca and the perinuclear zone, the number of Fos-positive neurones was significantly increased after phenylephrine infusion. Sino-aortic denervation blocked the significant increase in both regions. After volume expansion, a significant increase in Fos staining was observed only in the perinuclear zone of the supraoptic nucleus. This increase was not blocked by sino-aortic denervation. Our results indicate that both the diagonal band of Broca and the perinuclear zone of the supraoptic nucleus are activated by stimulating arterial baroreceptors; however, the perinuclear zone of the supraoptic nucleus is stimulated during volume expansion. Furthermore, the activation of perinuclear zone of the supraoptic nucleus after volume expansion is not dependent on intact arterial baroreceptors.

Molecular Neuroimaging of Post-Injury Plasticity

“…Enhanced ZsYellow1 expression was obtained by using an optimized c-fos promoter, leading to 16-fold increases in mRNA accumulation via activation of the cAMP-responsive (CRE) and the serum-responsive (SRE) promoter elements (Susini et al, 2000). C-fos expression has been shown to significantly increase in the CNS as a response to various physiological stimuli (Tian and Bishop, 2002) (Lin et al, 2011) (Curran and Morgan, 1995; Dampney et al, 1995; Cunningham et al, 2002). Previous studies obtained in vitro have shown that c-fos mRNA expression can be observed within five minutes following stimulation, and peaks 10-20 minutes after stimulation (Greenberg and Ziff, 1984; Flavell and Greenberg, 2008).…”

Histological and cytological study of the bed nuclei of the stria terminalis in adult rat. II. Oval nucleus: Extrinsic inputs, cell types, neuropil, and neuronal modules

“…physiological grounds, the Ov has been implicated in a wide variety of adaptative responses (Herman and Cullinan, 1997;Day et al, 1999Day et al, , 2001Cunningham et al, 2002;Engström et al, 2003;Amir et al, 2004;Nakagawa et al, 2005). Notably, some neurons and fibers in the Ov are immunnoreactive to CRF (CRF-I; and to CRF-binding.protein (Peto et al, 1999), respectively.…”

Induction of c-Fos and ΔFosB Immunoreactivity in Rat Brain by Vagal Nerve Stimulation

“…Regions of interest were identified using the rat brain stereotaxic atlas of Paxinos and Watson (1986). Three to six images were taken from each region for each animal bilaterally as previously described (Cunningham et al, 2002(Cunningham et al, , 2007Howe et al, 2004;Ji et al, 2005). The number of c-Fos or DFosB positive cells were recorded for each image and averaged for each animal.…”

“…The number of c-Fos or DFosB positive cells were recorded for each image and averaged for each animal. Counts were generated by observers who were blind to the treatment condition associated with the images (Cunningham et al, 2002(Cunningham et al, , 2007Howe et al, 2004;Ji et al, 2005).…”

“…Each brain was marked on the left side (ipsilateral to the VNS implant) and sectioned in a cryostat. Three serial sets of 40 mm coronal sections from each brain were placed in cryoprotectant and stored at À201C until processed for immunohistochemistry (Cunningham et al, 2002).…”