MODEL RELEASED. Alzheimer's disease research. Researcher holding a cell culture, grown to evaluate the health benefits of Melissa oil, an oil derived from the lemon balm plant (Melissa officinalis). It is thought to alleviate agitation symptoms suffered in the late stages of Alzheimer's and may also improve the levels of attention of Alzheimer's patients. To test this, a nutrient medium (pink) has been inoculated with human embryonic kidney cells (HEK 293) expressing the GABA(A) receptor, a major inhibitory receptor in the brain. Melissa oil is then added to test for receptor-binding activity. Photographed at the Centre for Integrative Neuroscience (CINS) at Durham University, UK.