Postnatal development of voltage-sensitive Na+ channels in rat brain.

摘要: Previous studies have shown that mammalian neuronal excitability increases with age, and this may be related to development of Na+ channels. In addition, evidence suggests channels are involved in the response O2 deprivation. Because this, we wished examine pharmacologic properties neuroanatomical distribution newborn brain as a function age. study, used ligand-binding techniques autoradiography 3H-saxitoxin (STX) investigate Na(+)-channel brains rats at postnatal days 0, 3, 10, 21, 35, 120. We found (1) each area examined, Scatchard plots for STX binding were linear both immature mature ligand concentration range 0.4-64 nM; slopes, however, different between areas or ages, Kd values ranging 1 5 (2) STX-binding density was more than tenfold lower rostral cerebellum birth adult increased age; (3) brainstem higher other such cortex cerebellum, which is opposite adult; (d) had developing pattern an early-peak level (P10-21) level.(ABSTRACT TRUNCATED AT 250 WORDS)