Oxytocin neurons in the rat hypothalamus exhibit c-fos immunoreactivity upon osmotic stress.
In order to evaluate the responses to osmotic stress of oxytocinergic neurons in vivo, we have studied oxytocin (OXY) and c-fos protein expression in the brain by means of double-immunostaining. C-fos immunoreactivity was detected in a subset of OXY neurons, as well as in other neurons non-immunoreactive for OXY, as early as 90 min after intraperitoneal injection of a hypertonic saline solution. C-fos expression was found in approx. 70% of OXY-immunoreactive neurons in the supraoptic (SON), lateral subcommisural (LSN) and paraventricular (PVN) nuclei, and not in OXY neurons in other hypothalamic areas. The expression of c-fos may be used as a means to map the circuitry by which osmotic stimulation activates OXY-containing neurons, and thus provide further insights into the functions with which OXY may be associated.
Giovannelli
L
L
Department of Neuropharmacology, Scripps Clinic and Research Foundation, La Jolla, CA 92037.
Shiromani
P J
PJ
Jirikowski
G F
GF
Bloom
F E
FE
D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D007031:Hypothalamus / Q000378:metabolism / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009928:Organ Specificity; D010121:Oxytocin / Q000032:analysis*; D011505:Protein-Tyrosine Kinases / Q000032:analysis; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D016760:Proto-Oncogene Proteins c-fos; D011519:Proto-Oncogenes; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012462:Saline Solution, Hypertonic; D013312:Stress, Physiological
D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D012462:Saline Solution, Hypertonic; D010121:Oxytocin; D011505:Protein-Tyrosine Kinases