Fos expression induced by warming the preoptic area in rats.
The preoptic area (POA) occupies a crucial position among the structures participating in thermoregulation, but we know little about its efferent projections for controlling various effector responses. In this study, we used an immunohistochemical analysis of Fos expression during local warming of the preoptic area. To avoid the effects of anesthesia or stress, which are known to elicit Fos induction in various brain regions, we used a novel thermode specifically designed for chronic warming of discrete brain structures in freely moving rats. At an ambient temperature of 22 degrees C, local POA warming increased Fos immunoreactivity in the supraoptic nucleus (SON) and the periaqueductal gray matter (PAG). Exposure of animals to an ambient temperature of 5 degrees C induced Fos immunoreactivity in the magnocellular paraventricular nucleus (mPVN) and the dorsomedial region of the hypothalamus (DMH). Concurrent warming of the POA suppressed Fos expression in these areas. These findings suggest that thermal information from the preoptic area sends excitatory signals to the SON and the PAG, and inhibitory signals to the mPVN and the DMH.
Yoshida
Kyoko
K
Department of Physiology and Biosignalling, Graduate School of Medicine, Osaka University, Yamadaoka 2-2, Suita, Osaka 565-0871, Japan.
Maruyama
Megumi
M
Hosono
Takayoshi
T
Nagashima
Kei
K
Fukuda
Yutaka
Y
Gerstberger
Ruediger
R
Kanosue
Kazuyuki
K
D000818:Animals; D001833:Body Temperature Regulation / Q000502:physiology*; D002452:Cell Count; D004302:Dorsomedial Hypothalamic Nucleus / Q000166:cytology / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D006979:Hyperthermia, Induced; D007150:Immunohistochemistry; D008297:Male; D009434:Neural Pathways / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000378:metabolism; D010487:Periaqueductal Gray / Q000166:cytology / Q000378:metabolism; D011301:Preoptic Area / Q000166:cytology / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013495:Supraoptic Nucleus / Q000166:cytology / Q000378:metabolism; D015854:Up-Regulation / Q000502:physiology*
D016760:Proto-Oncogene Proteins c-fos