Recurrent Hypoglycemia in Type 1 Diabetes (Aim 2)

Inclusion Criteria: * Type 1 diabetes diagnosed on clinical or laboratory grounds * Diabetes duration 2 - 30 years * Hemoglobin A1C \<8.5% Exclusion Criteria: * Impaired awareness of hypoglycemia as determined by the Cox and Gold questionnaires * Pregnant or plan to become pregnant during the study period * Uncontrolled hypertension (blood pressure \> 145/95 mmHg at screening) * Evidence of autonomic neuropathy (presence of orthostatic hypotension or history of gastroparesis) * Proliferative retinopathy * Impaired kidney function (GFR \< 45) * History of myocardial infarction, stroke, seizures, neurosurgical procedures, major depression requiring hospitalization within the last 5 years, arrhythmias * Current substance abuse * Use of drugs that can alter glucose metabolism including but not limited to glucocorticoids and niacin, and excluding insulin and glucose lowering drugs used to treat diabetes, as determined by a clinician * Inability to undergo MRI scanning, including but not limited to unable to remain still in an MRI scanner for more than 30 minutes, claustrophobia, presence of paramagnetic substances or pacemakers in body, weight over 300 lbs * Unable to complete all study visits or procedures, as determined by the investigator