Abstract
Glucocorticoids exert negative feedback in the anterior hypothalamus (AH) during lipopolysaccharide (LPS)-induced fevers, but the central location of their negative feedback during psychological stress-induced fever has not been determined. To confirm that glucocorticoid modulation of LPS fever occurs in the AH, adrenalectomized animals were injected intrahypothalamically with either 0.25 ng of corticosterone or vehicle followed by 50 μg/kg LPS intraperitoneally. Animals pretreated with corticosterone developed significantly smaller fevers (P = 0.007) than animals given vehicle. To determine if glucocorticold modulation during psychological stress-induced fever may occur in the hippocampus, the fornix was transected to block hippocampal communication with the AH. This resulted in significantly larger psychological stress-induced fevers (P = 0.02) compared with sham-operated animals. There were no differences between these groups for LPS-induced fevers (P = 0.92). To determine where in the hippocampus glucocorticoids might exert their negative feedback during psychological stress, rats were microinjected with either 1 ng RU-38486 (a type II glucocorticoid receptor antagonist) or vehicle into the dentate gyrus prior to exposure to the open field. There were no differences between the psychological stress-induced fevers of the RU-38486- and vehicle-injected groups, supporting the hypothesis that these fevers are modulated elsewhere in the hippocampus. Our data support the hypothesis that glucocorticoids modulate LPS-induced fever in the AH and do not involve the hippocampus, and that psychological stress-induced fevers are modulated by neural connections between the hippocampus and the hypothalamus. The precise sites of action of glucocorticoid negative feedback on stress-induced fevers in the hippocampus (or other brain regions) are not yet known.
| Original language | English (US) |
|---|---|
| Pages (from-to) | R732-R737 |
| Journal | American Journal of Physiology - Regulatory Integrative and Comparative Physiology |
| Volume | 271 |
| Issue number | 3 40-3 |
| State | Published - Sep 1 1996 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Physiology
- Physiology (medical)
Cite this
The CNS site of glucocorticoid negative feedback during LPS- and psychological stress-induced fevers. / Morrow, Lee E.; McClellan, Jennifer L.; Klir, John J.; Kluger, Matthew J.
In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology, Vol. 271, No. 3 40-3, 01.09.1996, p. R732-R737.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The CNS site of glucocorticoid negative feedback during LPS- and psychological stress-induced fevers
AU - Morrow, Lee E.
AU - McClellan, Jennifer L.
AU - Klir, John J.
AU - Kluger, Matthew J.
PY - 1996/9/1
Y1 - 1996/9/1
N2 - Glucocorticoids exert negative feedback in the anterior hypothalamus (AH) during lipopolysaccharide (LPS)-induced fevers, but the central location of their negative feedback during psychological stress-induced fever has not been determined. To confirm that glucocorticoid modulation of LPS fever occurs in the AH, adrenalectomized animals were injected intrahypothalamically with either 0.25 ng of corticosterone or vehicle followed by 50 μg/kg LPS intraperitoneally. Animals pretreated with corticosterone developed significantly smaller fevers (P = 0.007) than animals given vehicle. To determine if glucocorticold modulation during psychological stress-induced fever may occur in the hippocampus, the fornix was transected to block hippocampal communication with the AH. This resulted in significantly larger psychological stress-induced fevers (P = 0.02) compared with sham-operated animals. There were no differences between these groups for LPS-induced fevers (P = 0.92). To determine where in the hippocampus glucocorticoids might exert their negative feedback during psychological stress, rats were microinjected with either 1 ng RU-38486 (a type II glucocorticoid receptor antagonist) or vehicle into the dentate gyrus prior to exposure to the open field. There were no differences between the psychological stress-induced fevers of the RU-38486- and vehicle-injected groups, supporting the hypothesis that these fevers are modulated elsewhere in the hippocampus. Our data support the hypothesis that glucocorticoids modulate LPS-induced fever in the AH and do not involve the hippocampus, and that psychological stress-induced fevers are modulated by neural connections between the hippocampus and the hypothalamus. The precise sites of action of glucocorticoid negative feedback on stress-induced fevers in the hippocampus (or other brain regions) are not yet known.
AB - Glucocorticoids exert negative feedback in the anterior hypothalamus (AH) during lipopolysaccharide (LPS)-induced fevers, but the central location of their negative feedback during psychological stress-induced fever has not been determined. To confirm that glucocorticoid modulation of LPS fever occurs in the AH, adrenalectomized animals were injected intrahypothalamically with either 0.25 ng of corticosterone or vehicle followed by 50 μg/kg LPS intraperitoneally. Animals pretreated with corticosterone developed significantly smaller fevers (P = 0.007) than animals given vehicle. To determine if glucocorticold modulation during psychological stress-induced fever may occur in the hippocampus, the fornix was transected to block hippocampal communication with the AH. This resulted in significantly larger psychological stress-induced fevers (P = 0.02) compared with sham-operated animals. There were no differences between these groups for LPS-induced fevers (P = 0.92). To determine where in the hippocampus glucocorticoids might exert their negative feedback during psychological stress, rats were microinjected with either 1 ng RU-38486 (a type II glucocorticoid receptor antagonist) or vehicle into the dentate gyrus prior to exposure to the open field. There were no differences between the psychological stress-induced fevers of the RU-38486- and vehicle-injected groups, supporting the hypothesis that these fevers are modulated elsewhere in the hippocampus. Our data support the hypothesis that glucocorticoids modulate LPS-induced fever in the AH and do not involve the hippocampus, and that psychological stress-induced fevers are modulated by neural connections between the hippocampus and the hypothalamus. The precise sites of action of glucocorticoid negative feedback on stress-induced fevers in the hippocampus (or other brain regions) are not yet known.
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UR - http://www.scopus.com/inward/citedby.url?scp=0029816757&partnerID=8YFLogxK
M3 - Article
C2 - 8853398
AN - SCOPUS:0029816757
VL - 271
SP - R732-R737
JO - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
JF - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
SN - 0363-6119
IS - 3 40-3
ER -