Immunofluorescent Identification of α1 Isoform Subunits of Voltage-Gated Ca2+-Channels of CaV1, CaV2, and CaV3 Families in Areas of Cholinergic Synapses of Somatic Muscles in Earthworm Lumbricus terrestris

The α1 subunits of the voltage-gated Ca 2+ -channels α1S, α1C, α1D, and α1F in channels of the Ca V 1.1–1.4 type; α1A in a channel of Ca V 2.1 type; α1E in a channel of Ca V 2.3 type; and α1G, α1H, and α1I in a channel of Ca V 3.1–3.3 type, as well as the synaptic vesicle exo-endocytotic protein synaptophysin, were identified using fluorescence and confocal microscopy in the somatic muscle of the earthworm Lumbricus terrestris . The presynaptic membrane of cholinergic synapses contains voltage-gated Ca 2+ -channels of Ca V 1.1 and Ca V 1.2 (including α1S and α1C subunits), Ca V 2.1 (with α1A subunit), Ca V 2.3 (with α1E subunit), and Ca V 3.2 and Ca V 3.3 (with subunits α1H, α1I) types, while Ca V 1.3 and Ca V 1.4 Ca2 + -channels with subunits α1D and α1F and Ca V 3.1 channels with subunit α1G are predominantly parts of the muscle membranes.