Streptanthus bracteatus Streptanthus bracteatus Streptanthus bracteatus is a species of flowering plant in the mustard family known by the common names bracted jewelflower and bracted twistflower. It is endemic to Texas in the United States. This annual or biennial herb has a branching stem up to 1.2 meters tall. It is hairless and generally waxy in texture. The basal leaves have lobed or toothed blades on long petioles, and the leaves higher on the stem have smooth or toothed edges. The inflorescence is a raceme of flowers and bracts. Each flower has a bell-shaped calyx of sepals and four purple petals which
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