Silene invisa cyme of up to three flowers at the top of the stem. Each flower has a bell-shaped calyx of fused sepals lined with ten green veins and covered in short, glandular hairs. The strap-shaped or rectangular petals have blunt tips or may be notched. They are whitish to pinkish or lavender and sometimes barely protrude from the calyx. Silene invisa Silene invisa is a species of flowering plant in the pink family known by the common names red fir catchfly and short-petaled campion. It is endemic to California, where it is known only from the southernmost Cascade Range and northernmost
Calyx of Held high frequency sound localization. This synapse has been described as the largest in the brain. The related endbulb of Held is also a large axon terminal smaller synapse (15-30 µm in diameter) found in other auditory brainstem structures, namely the cochlear nucleus. As with the calyces, these synapses promote fast, efficient information transfer. The calyx of Held holds vesicles containing glutamate on the presynaptic terminal, the vesicles are released upon stimulation (originating in the auditory system). The glutamate then binds to two known glutamate receptors, AMPA- and NMDA receptors. Commonly used in research due to its large size, the calyx