PubMed · 4980311
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
E J Field, A Peat. 1969. Structural changes in scrapieaffected brain.. https://doi.org/10.1042/bj1140019p
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Recent studies of the human amygdala have shed new light on its roles in two distinct, but related processes: emotional memory and the evaluation of emotional stimuli.
Both neuroendocrine and behavioral responses to stressors are reduced in lactating animals. In these studies we determined whether Fos induction following treatment with urethane would differ between nonlactating and lactating rats. Urethane treatment produced robust Fos expression in the central nucleus of the amygdala and the paraventricular and supraoptic nuclei of the hypothalamus 1 h after treatment. Fos expression in both the paraventricular and supraoptic nuclei was attenuated in lactating rats compared to that seen in nonlactating animals but Fos expression in the central nucleus of the amygdala did not differ between these two groups. Removing litters from lactating rats 48 h prior to urethane administration restored the Fos response in the parvocellular division of the paraventricular nucleus (PVN) to the level seen in nonlactating rats.
The distribution and time course of Fos expression in neurons in the central nucleus of the amygdala (CeA) were studied in endotoxemic rats in two separate experiments. In each case, the severity of the endotoxin (lipopolysaccharide; LPS) challenge was characterized by using physiological outcome variables, including blood pressure and heart rate. Throughout the rostrocaudal extent of the CeA, extensive Fos staining was found 3 hours after injection with a hypotensive dose of Salmonella enteritidis LPS. Hypotension alone has been reported to induce Fos in the CeA; therefore, the remaining experiments were performed by using a lower dose of Escherichia coli LPS that did not cause hypotension. The nonhypotensive dose of E. coli LPS also induced Fos in large numbers of neurons of the CeA, with peak staining at 2 hours and Fos staining persisting for 6 hours after LPS injection. Tachycardia and fever after LPS also persisted for at least 6 hours. CeA Fos staining during nonhypotensive endotoxemia was predominantly located in the lateral subnucleus, although Fos-stained medial sub-nucleus neurons were also present. Additional forebrain regions that showed persistent Fos staining 6 hours after LPS included the parvocellular paraventricular nucleus of the hypothalamus, the bed nucleus of the stria terminalis, and the medial preoptic area. Forebrain regions that contained Fos-stained nuclei at earlier time points, but not at 6 hours, included the supraoptic nucleus, magnocellular regions of the paraventricular nucleus of the hypothalamus, the subfornical organ, and the organum vasculosum of the lamina terminalis. Few CeA neurons showed Fos staining in rats that were restrained in a ventilated plastic tube. Neurons in the lateral septal nucleus and the medial amygdaloid nucleus, which have numerous Fos-stained nuclei after stressors such as footshock or restraint, did not show Fos staining above control levels after LPS administration. Activation of CeA neurons after intravenous LPS may indicate persistent drive from vagal afferents and may implicate the CeA in the autonomic, neuroendocrine, and/or behavioral responses to this treatment.