Calcium-binding protein-immunoreactive projection neurons in the caudal subnucleus of the spinal trigeminal nucleus of the rat.
It has been reported that calcium-binding proteins are good markers for different sets of neurons in various brain regions. We examined expression of the main calcium-binding proteins in projection neurons in the rat medullary dorsal horn (MDH) by combining immunofluorescence histochemistry for calbindin D28k (CB), calretinin (CR) and parvalbumin (PV) with the retrograde tract-tracing method. A fluorescence tracer, tetramethylrhodamine-dextran amine (TMR-DA), was injected into the parabrachial, thalamic or hypothalamic region. After such injections, a number of PV-, CR-, and/or CB-immunoreactive MDH neurons were labeled retrogradely with TMR-DA. Triple-immunofluorescence histochemistry further revealed that a number of CB-, CR-, or PV-immunoreactive TMR-DA-labeled MDH neurons showed immunoreactivity for substance P receptor (NK1), and that they expressed immunoreactivity for c-fos protein in the rats which were injected with formalin into the lips. Thus, it was indicated that some of CB-, CR-, or PV-containing projection neurons in the MDH might be involved in the transmission of nociceptive stimuli.
Li
J L
JL
Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, People's Republic of China.
Li
Y Q
YQ
Li
J S
JS
Kaneko
T
T
Mizuno
N
N
D000818:Animals; D002135:Calcium-Binding Proteins / Q000032:analysis*; D007031:Hypothalamus / Q000737:chemistry / Q000166:cytology; D008297:Male; D009434:Neural Pathways / Q000737:chemistry / Q000166:cytology; D009474:Neurons / Q000737:chemistry* / Q000166:cytology*; D009619:Nociceptors / Q000737:chemistry; D011149:Pons / Q000737:chemistry / Q000166:cytology; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D018040:Receptors, Neurokinin-1 / Q000032:analysis; D013788:Thalamus / Q000737:chemistry / Q000166:cytology; D014275:Trigeminal Caudal Nucleus / Q000737:chemistry* / Q000166:cytology*
D002135:Calcium-Binding Proteins; D016760:Proto-Oncogene Proteins c-fos; D018040:Receptors, Neurokinin-1