Additional Study Information: Neurodegenerative diseases are conditions where the brain cells break down, causing mental and/or physical impairment. Alzheimer's Disease is a neurodegenerative disorder that affects millions of individuals and causes irreversible memory loss and cognitive impairment. Amyotrophic lateral sclerosis is also and incurable disorder that causes patients irreversible paralysis, which results in death due to inability to breathe and suffocation. These disease have been shown to be associated with abnormalities in the microtubules, cellular structures that help support the shape of the cells. This study will explore an experimental imaging test to see if it can be used to help doctors identify early microtubule changes. The test involves the injection of a radioactive compound called 11CMPC6827. We believe that 11CMPC6827 will go to cells and bind to microtubules. Special cameras called Positron Emission Tomography (PET)/CT cameras will be used to allow doctors to view where the 11CMPC6827 goes in the body, as this is the first time this radiolabeled agent is being used in humans. In this study, doctors will give 11CMPC6827 to up to five healthy volunteers to see where it goes in the body of people who presumable have normal microtubule function. Then doctors will give 11CMPC6827 to up to 30 additional subjects (healthy controls and patients with Alzheimer's Disease or ALS) to focus on imaging the brain for extended times. The research-imaging drug in this study is 11CMPC6827. The radioactive drug in this study is experimental, meaning it is not approved by the FDA and can only be used in research studies.