- 作者: Chun-Kuei Su; Chiu-Ming Ho; Hsiao-Hui Kuo; Yu-Chuan Wen; Chok-Yung Chai
- 作者服務機構: Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, R.O.C.
- 中文摘要: --
- 英文摘要:
An isolated thoracic spinal cord of the neonatal rat in vitro spontaneously generates
sympathetic nerve discharge (SND) at ~25°C, but it fails in SND genesis at ≤ 10°C.
Basal levels of the c-Fos expression in the spinal cords incubated at ≤ 10°C and
~25°C were compared to determine the anatomical substrates that might participate in
SND genesis. Cells that exhibited c-Fos immunoreactivity were virtually absent in the
spinal cords incubated at ≤ 10°C. However, in the spinal cords incubated at ~25°C,
c-Fos-positive cells were found in the dorsal laminae, the white matter, lamina X, and
the intermediolateral cell column (IML). Cell identities were verified by double
labeling of c-Fos with neuron-specific nuclear protein (NeuN), glial fibrillary acidic
protein (GFAP), or choline acetyltransferase (ChAT). The c-Fos-positive cells
distributed in the white matter and lamina X were NeuN-negative or GFAP-positive
and were glial cells. Endogenously active neurons showing c-Fos and NeuN double
labeling were scattered in the dorsal laminae and concentrated in the IML. Double
labeling of c-Fos and ChAT confirmed the presence of active sympathetic
preganglionic neurons (SPNs) in the IML. Suppression of SND genesis by
tetrodotoxin (TTX) or mecamylamine (MECA, nicotinic receptor blocker) almost
abolished c-Fos expression in dorsal laminae, but only mildly affected c-Fos
expression in the SPNs. Therefore, c-Fos expression in some SPNs does not require
synaptic activation. Our results suggest that spinal SND genesis is initiated from some
spontaneously active SPNs, which are capable of TTX- or MECA-resistant c-Fos
expression. - 中文關鍵字: --
- 英文關鍵字: --