Optical identification of calcium-dependent action potentials transiently expressed in the embryonic rat brainstem

摘要: Abstract Using multiple-site optical recording of transmembrane potential changes, we have found a new type calcium-dependent action expressed transiently in the embryonic rat dorsal motor nucleus vagus nerve. Slice preparations with nerve fibers attached were dissected from 12- to 16-day-old (E12–E16) brainstems, and they stained voltage-sensitive merocyanine–rhodanine dye (NK2761). Electrical activities response vagal stimuli optically recorded simultaneously many sites using 1020- or 128-element photodiode array measuring systems. In brainstem preparations, two types potential-related signals identified. One was detected dorsolateral region, related sensory activity (Type I). The other dorsomedial corresponded II). We difference ionic basis Type I vs II signals. signal not altered Ca 2+ -free bathing solution eliminated by tetrodotoxin, suggesting that is mediated Na + currents. at early developmental stages (E12–E13, some E14) also independent . However, later (E15–E16, did depend upon : it Ringer's solution, blocked Cd , Ni Mn elicited Sr -containing where CaCl 2 replaced SrCl These results suggest cation which dominates motoneuron changes during development, this change occurs around E14. With pharmacological analysis channel blockers, show mediating distinct T-, L-, N-, P- Q-type channels. Because adult mammals mainly particular development.