In developing central nervous system therapeutics, delivery across the blood-brain barrier remains one of the biggest challenges. In the present study, a liposome, surface-modified with an aptamer for the transferrin receptor, was used to facilitate aptamer delivery from the periphery into the brain. Repeated, systemic administration of the aptamer produced no behavioral or neurodegenerative effects. In a behavioral experiment using cocaine administration to raise concentrations of dopamine, aptamer pretreatment reduced cocaine-induced hyperlocomotion. Systemic pretreatment with control manipulations of the aptamer delivery system did not alter hyperlocomotion. RT-PCR was used to detect the aptamer, confirming the delivery of the aptamer into the brain. Differential fluorescence was found based on the presence or absence of transferrin receptor aptamers bound to rhodamine-tagged liposomes. Results suggest that modified liposomes delivered aptamer into the brain. This multi-aptamer system has the potential to be easily modified to deliver treatments for a variety of neural targets.