Silene marmorensis a terminal cyme of flowers at the top of the stem, and some flowers may occur in the leaf axils. Each flower has a hairy, veined calyx of fused sepals. The flowers bloom at night, the five pinkish or green-tinged petals opening at the tip of the calyx. This species is threatened by logging operations and other degradation of its habitat. Silene marmorensis Silene marmorensis is a rare species of flowering plant in the pink family known by the common names Marble Mountain catchfly, Marble Mountain campion, and Somes Bar campion. It is endemic to the southern Klamath Mountains of
Calyx of Held sensitivity. Both low-threshold K channels and high-threshold delayed rectifier-type K channels are present in presynaptic neurons. There are four low-threshold K channels present: K1.1, K1.2, K1.3, and K7.5. K1.1 and K1.2 are located in the transition zone between the axon and the terminal, while K1.3 K7.5 are located in the calyx. There is a calcium activated potassium channel expressed in the calyx, however this type of channel does not contribute to neurotransmitter release. Within the span of one week, mice subjects (P7 to P14) showed that the density of the K1 and K3 low threshold channels increases, which in turn