The SNIFF 3-Week Aptar Device study will involve using a device to administer insulin or
placebo through each participant's nose or intra-nasally. Insulin is a hormone that is
produced in the body. It works by lowering levels of glucose (sugar) in the blood. This study
is measuring how much insulin the device delivers. In addition, this study will look at the
effects of insulin or placebo administered intra-nasally using an intranasal delivery device
on memory, blood, and cerebrospinal fluid (CSF).