Muscle contraction ends when calcium ions are pumped back to the sarcomere. During stimulation of the muscle cell, the motor neuron releases the neurotransmitter acetylcholine which travels across the neuromuscular junction (the synapse between the terminal bouton of the neuron and the muscle cell).
Hellebore. Helleborus. Hellebores are so easy and so pretty, they have a place in nearly every landscape. Their exquisite bowl-or saucer-shape flowers in white (often speckled), pinks, yellows, or maroon remain on the plant for several months, even after the petals have fallen. Deer-resistant and mostly evergreen, hellebores' divided leaves rise on sturdy stems and may be serrated (like a knife) along the edges. Grow hellebores in shade where soil remains moist; some hellebores prefer acid or alkaline conditions, depending on variety.
Give this evergreen shrub moist, well-drained, acid, organic soil. In the South, site it in shade. USDA Zones 4b to 7. The so-called Christmas rose is actually a hellebore (Helleborus niger), and for areas of the country where winter flowers are a rarity, hellebores are a delight.