Exocytosis and Endocytosis (IMAGE) University of Utah Caption The left electron microscope image shows "exocytosis." Parts of two nerve cells from a mouse brain are shown, top and bottom, with the gap or synapse between them appearing as horizontal lines. The top nerve cell is filled with tiny round bubbles known as vesicles. One of those vesicles, which appears like an upside-down "U" in the middle of the image, is fusing to the inside of the nerve cell to send its load of neurotransmitters to the nerve cell below. The right image shows "endocytosis," the recycling of a nerve cell vesicle. The recycled vesicle that is taking shape appears as the large bubble toward the right center of the image. University of Utah and German biologists made these photos using a new method to "flash and freeze" nerve cells in action. Credit Shigeki Watanabe, University of Utah. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.