Autoradiographic analysis in rat brain of the postnatal ontogeny of voltage-dependent Na+ channels, Ca2+-dependent K+ channels and slow Ca2+ channels identified as receptors for tetrodotoxin, apamin and (-)-desmethoxyverapamil.
The postnatal development of the distribution of 3 different ionic channel proteins in rat brain was studied using light microscopic autoradiography. [3H]Ethylenediaminetetrodotoxin, [125I]apamin and (-)-[3H]desmethoxyverapamil were used to label one class of voltage-dependent Na+ channel proteins, one class of Ca2+-dependent K+ channel proteins, and the slow Ca2+ channel protein, respectively. Ca2+-dependent K+ channel proteins are detected very early in the germinative zone. They are associated to neuronal somas during their migration and their maturation. In hippocampus and cerebral cortex, apamin binding sites are already present at birth and their density increases to day 20 postnatal when the adult localization is established. Slow Ca2+ channel protein development occurs later in CNS ontogenesis. The development of slow Ca2+ channels seems to follow the development of dendrites. Density of these channel proteins increases regularly until adult age. At the resolution level of this analysis, Na+ channel proteins are absent in diencephalon at birth. Their appearance and their increase in density are strictly correlated to the synaptogenesis in particular in cerebral and cerebellar cortex and hippocampus. Although cerebellum, neocortex and hippocampus have been particularly analyzed, other brain structures have also been examined.
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000254:growth & development / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D007473:Ion Channels / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels; D051381:Rats; D011919:Rats, Inbred Strains; D017981:Receptors, Neurotransmitter / Q000378:metabolism; D012964:Sodium / Q000378:metabolism*; D015222:Sodium Channels; D014700:Verapamil / Q000031:analogs & derivatives / Q000378:metabolism
D002352:Carrier Proteins; D007473:Ion Channels; D015221:Potassium Channels; D017981:Receptors, Neurotransmitter; D015222:Sodium Channels; C033799:apamin receptor; C023790:tetrodotoxin-binding protein; C043184:4-desmethoxyverapamil; D012964:Sodium; D014700:Verapamil; D011188:Potassium; D002118:Calcium