Expression of calcium channel CaV1.3 in cat spinal cord: light and electron microscopic immunohistochemical study

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review


In spinal neurons, plateau potentials serve to amplify neuronal input signals. To a large extent, the underlying persistent inward current is mediated by a subtype of the L-type calcium channel (Ca(V)1.3). In the present investigation, we have studied its distribution and cellular localization in the cat spinal cord by light and electron microscopic immunohistochemistry. The results show that Ca(V)1.3-like immunoreactivity is widely distributed in all segments of the spinal cord but that the distribution in the different laminae of the spinal gray matter varies, with the highest density of labeled neurons in lamina IX and the lowest in lamina II. The labeling intensity was highest in neuronal somata, but a certain length of the proximal dendrite was also labeled. Some neuronal groups exhibited a particularly dense labeling; these include the lateral motoneuronal group in the cervical and the lumbar enlargements and the phrenic nucleus in cervical, Clarke's nucleus in lower thoracic and upper lumbar, and Onuf's nucleus in upper sacral segments. At the ultrastructural level, Ca(V)1.3-immunoreactive products were found in neuronal somata and dendrites of different sizes. In the soma, they were predominantly associated with the rough endoplasmic reticulum but some also with the plasma membrane. In dendrites, they were associated with both intracellular organelles, including microtubules and microchondria, and the plasma membrane. These results indicate that significant proportions of the neurons in cat spinal cord, including projection neurons, interneurons, and motoneurons, are endowed with ion channels that subserve persistent inward currents and act to amplify synaptic input signals.
TidsskriftJournal of Comparative Neurology
Udgave nummer1
Sider (fra-til)1109-1127
Antal sider19
StatusUdgivet - 2008
Udgivet eksterntJa

Bibliografisk note

CURIS 2008 5200 147

Fingeraftryk Dyk ned i forskningsemnerne om 'Expression of calcium channel Ca<sub>V</sub>1.3 in cat spinal cord: light and electron microscopic immunohistochemical study'. Sammen danner de et unikt fingeraftryk.