Neurological Disorders: Stress-Induced Hyperthermia
Stress-induced hyperthermia (SIH), mediated by the autonomic nervous system, is well known to occur prior to and during exposure to stress and or anxiety-inducing situations. In pathological forms it is considered to represent a symptom of generalized anxiety disorder. Decreased SIH has been observed in mGluR5 (glutamate receptor subtype 5) knockout mice. Consistent with this finding, the selective mGluR5 antagonist MPEP (2-methyl-6-(phenylethynyl)pyridine) acts as an anxiolytic in rodent models of anxiety, including SIH (Brodkin et al., 2002). Further pharmacological validation of this assay includes the reduction of SIH by administration of buspirone (5-HT1A receptor agonist) or diazepam (benzodiazepine receptor agonist) (Olivier et al., 1998). Body temperature measurements are recorded with a Physitemp Instruments TH-5 Thermalert and RET-3 rectal probes. Male wild type and homozygous mice (heterozygotes tested when project is homozygote lethal) are tested in their colony room to prevent additional stress from transporting cages. Basal body temperatures are recorded as T1. Ten minutes later the stress-enhanced body temperature is recorded and designated T2. The difference between T2 and T1 is calculated as delta T (T2-T1 = ΔT).
Displayed below is a sample graph of how SIH measures are presented. In comprehensive phenotypic data packages graphs are interactive. Raw or calculated data and statistics can be seen by clicking on points in the graph.
Figure illustrates median stress-induced change in body temperature of LV1 mice. Median delta values for homozygous (red diamond), wild type littermates (green circle), and recent historical wild types (purple line) are plotted against long-term historical stress-induced changes in body temperature (± 2 standard deviations) for wild type values are calculated from data collected within 60 days of current measures and long-term historical values are derived from data collected on more than 10,000 wild type mice.
Brodkin J, Bradbury M, Busse C, Warren N, Bristow LJ, Vareny MA. (2002) Reduced stress-induced hyperthermia in mGluR5 knockout mice, European Journal of Neuroscience, 16:2241-2244.
Oliver PM, John SW, Purdy KE, Kim R, Maeda N, Goy MF, Smithies O. (1998) Natriuretic peptide receptor 1 expression influences blood pressures of mice in a dose-dependent manner, Proc Natl Acad Sci USA, 95:2547-2551.