Differential time course of angiotensin-induced AP-1 and Krox proteins in the rat lamina terminalis and hypothalamus
II. Institute of Physiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany Neuroscience Letters
(Impact Factor: 2.03).
01/1998; 241(2-3):87-90. DOI: 10.1016/S0304-3940(97)00957-9
We studied the time course of expression of the inducible transcription factors (ITF) c-Fos, FosB, c-Jun, JunB, JunD, Krox-20 and Krox-24, induced by a single intracerebroventricular injection of angiotensin II, in the subfornical organ (SFO), median preoptic nucleus (MnPO) paraventricular nucleus (PVN) and supraoptic nucleus (SON). c-Fos and Krox-24 were expressed rapidly in neurons of all four areas but completely disappeared after 4 h. FosB showed a delayed but persistent expression between 4 h and 24 h in the MnPO and PVN. c-Jun was induced in the MnPO, SFO and PVN after 1.5 h and in the SON after 4 h. JunB was selectively expressed in the MnPO and SFO and the level of JunD did not change. The expression of the pre-existing transcription factors SRF, CREB and ATF-2 which contribute to the transcriptional control of jun, fos and krox genes, was not affected by Ang II. Thus, we could show for the first time that an acute stimulation of AT receptors results in continual changes in ITF expression over 24 h.
Available from: Mirjam Bunck
- "In support of such a mechanism, transactivation by SRF at the AVP-derived CArG boxes contained in the minimal reporter plasmid was efficiently repressed when CBF-A protein levels were increased in Saos-2 cells. Interestingly, SRF, although moderately expressed in the hypothalamus (Herdegen et al., 1997; Stringer et al., 2002), is distinctly absent in the PVN (Blume et al., 1998). Conversely, CBF-A shows an intense expression in the PVN in this study and in a previous study (Rushlow et al., 1999), in addition to being widely expressed in many other areas of the brain including the olfactory bulb, hippocampus, cerebellum, and hindbrain and peripheral tissues such as the spleen, lung, and thymus. "
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ABSTRACT: Two inbred rat lines have been developed that show either high (HAB) or low (LAB) anxiety-related behavior. The behavioral phenotype correlates with arginine vasopressin (AVP) expression at the level of the hypothalamic paraventricular nucleus (PVN), but not supraoptic nucleus, with HAB animals overexpressing the neuropeptide in both magnocellular and parvocellular subdivisions of the PVN. We detected a number of single nucleotide polymorphisms (SNPs) in the AVP locus that differ between the HAB and LAB animals, two of which were embedded in cis-regulatory elements. The HAB-specific allele of the AVP gene promoter occurs in 1.5% of outbred Wistar rats and is more transcriptionally active in vivo, as revealed by allele-specific transcription studies in cross-mated HAB/LAB F1 animals. Interestingly, one specific SNP [A(-1276)G] conferred reduced binding of the transcriptional repressor CArG binding factor A (CBF-A) in the HAB allele, the consequent differential regulation of the AVP promoter resulting in an overexpression of AVP in vitro and in vivo. Furthermore, CBF-A is highly coexpressed in AVP-containing neurons of the PVN supporting an important role for regulation of AVP gene expression in vivo. Taken together, our results demonstrate a role for an AVP gene polymorphism and CBF-A in elevated AVP expression in the PVN of HAB rats likely to contribute to their behavioral and neuroendocrine phenotype.
Available from: Zuoxin Wang
- "Refs.  ) but, in some situations, can be sustained for many hours  . Since the brain areas examined [amygdala (Amyg), lateral septum (LS), nucleus accumbens (NAcc), bed nucleus of the stria terminalis (BNST), and medial preoptic area (MPOA)] are likely to serve multiple functions, it is unlikely that simple measures of acute activation will be sufficient to identify areas solely involved in pair bonding . "
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ABSTRACT: Repeated mating over a period of 6 h facilitates pair-bond formation in monogamous prairie voles. Using this paradigm, we examined fos expression in brain areas implicated in social behavior in voles. We hypothesized that the presence of the fos protein after a period of time sufficient for pair bonding to occur may indicate brain areas that are especially important in pair bond formation. We found elevated levels of fos immunoreactivity in the medial and cortical amygdala, medial preoptic area (MPOA), and bed nucleus of the stria terminalis (BNST) in females that mated several times over a 6-h period as compared to a variety of unmated controls. No treatment effects were found in the central amygdala, nucleus accumbens (NAcc), or lateral septum (LS). We suggest that areas that show evidence of fos expression after sufficient time for pair bonding to occur may be important in the formation of associations between the partner and mating stimuli.
Available from: etd.fcla.edu
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