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Distribution of substance P and neurokinin-1 receptor immunoreactivity in the suprachiasmatic nuclei and intergeniculate leaflet of hamster, mouse, and rat.
- Source :
-
The Journal of comparative neurology [J Comp Neurol] 2001 Sep 10; Vol. 438 (1), pp. 50-65. - Publication Year :
- 2001
-
Abstract
- The circadian pacemaker in the hypothalamic suprachiasmatic nuclei (SCN) receives photic information directly via the retinohypothalamic tract (RHT) and indirectly from retinally innervated cells in the thalamic intergeniculate leaflet (IGL) that project to the SCN. Using standard immunohistochemical methods, we examined the presence and distribution of substance P (SP) and the neurokinin-1 receptor (NK-1) in the SCN and IGL of rat and determined whether the patterns of immunostaining generalized to the SCN and IGL of Syrian hamster, Siberian hamster, and mouse. Terminals immunoreactive for SP were sparse within the SCN of Siberian and Syrian hamsters and mouse but were intense in the ventral, retinally innervated portion of the rat SCN. Immunostaining for the NK-1 receptor was mainly absent from the SCN of hamster and mouse. In contrast, a plexus of NK-1-ir cells and processes that was in close proximity to SP-ir terminals was found in the ventral SCN of the rat. Substance P-ir terminals were observed in the IGL of all four species, as were NK-1-ir cells and fibres. Double-labelled IGL sections of hamster or rat revealed SP-ir terminals in close apposition to NK-1-immunostained cells and/or fibres. These data indicate that SP could be a neurotransmitter of the RHT in rat, but not in hamster or in mouse, and they highlight potential species differences in the role of SP within the SCN circadian pacemaker. Such species differences do not appear to exist at the level of the IGL, where SP-ir and NK-1-ir were similar in all species studied.<br /> (Copyright 2001 Wiley-Liss, Inc.)
- Subjects :
- Animals
Axons metabolism
Cricetinae anatomy & histology
Geniculate Bodies cytology
Immunohistochemistry
Male
Mice
Mice, Inbred C57BL anatomy & histology
Rats
Rats, Wistar anatomy & histology
Suprachiasmatic Nucleus cytology
Cricetinae metabolism
Geniculate Bodies metabolism
Mice, Inbred C57BL metabolism
Rats, Wistar metabolism
Receptors, Neurokinin-1 metabolism
Substance P metabolism
Suprachiasmatic Nucleus metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9967
- Volume :
- 438
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- The Journal of comparative neurology
- Publication Type :
- Academic Journal
- Accession number :
- 11503152
- Full Text :
- https://doi.org/10.1002/cne.1301