Streptanthus cordatus stem. Flowers occur at intervals along the upper stem. Each has a calyx of sepals roughly a centimeter long which begin greenish yellow and mature purple. Four purple petals emerge from the tip of each calyx. The fruit is a thin, narrow silique which may reach 14 centimeters in length or longer. Streptanthus cordatus Streptanthus cordatus is a species of flowering plant in the mustard family known by the common name heartleaf twistflower. It is native to the western United States, where it can be found in many types of sagebrush, woodland, and forest habitat. It is a perennial herb
Calyx of Held third postnatal weeks, around the time of hearing onset, the calyx of Held develops its characteristic, highly fenestrated (many openings) appearance. Fenestration results in the membrane being reduced to numerous small compartments, which increase surface area of the presynaptic cleft. As the membrane becomes increasingly pinched into these bulb-like structures, synaptic vesicles are further grouped into these spaces, resulting in an increased number of docked vesicles. To compensate for the available spaces in the calyx, glial cells with glutamate receptors and transports are used to fill open spaces, ensuring efficient uptake of glutamate in the synapse. This physical change in