The present disclosure provides a method for delivering a neuroprotective polypeptide to at least a portion of a central nervous system (CNS) of a subject. The method includes administering to the systemic blood circulation of the subject a therapeutically effective amount of a neuroprotective polypeptide by a controlled-release formulation or a device providing a sustained release of the neuroprotective polypeptide including at least one neuroprotective polypeptide selected from the group consisting of GLP-1, exendin-4, or a therapeutically effective GLP-1 or exendin-4 analogue； the neuroprotective polypeptide binds to and activates a receptor that binds at least one of GLP-1, exendin-4, or a combination thereof； and the controlled-release neuroprotective formulation or the sustained release of the neuroprotective polypeptide enhances the delivery of the neuroprotective polypeptide across a blood-brain barrier (BBB) of the subject to at least a portion of the CNS relative to a rapid release formulation of the neuroprotective polypeptide. Also disclosed is a method of treating a subject with a CNS-related disease or reducing at least one symptom of a CNS-related disease in a subject in need thereof.La presente descripción proporciona un método para administrar un polipéptido neuroprotector a al menos una parte de un sistema nervioso central (SNC) de un sujeto. El método incluye administrar a la circulación sanguínea sistémica del sujeto una cantidad terapéuticamente efectiva de un polipéptido neuroprotector mediante una formulación de liberación controlada o un dispositivo que proporciona una liberación sostenida del polipéptido neuroprotector que incluye al menos un polipéptido neuroprotector seleccionado del grupo que consiste en GLP-1 exendina-4, o un análogo de GLP-1 o exendina-4 terapéuticamente efectivo； el polipéptido neuroprotector se une y activa un receptor que se une a al menos uno de GLP-1, exendina-4, o una combinación de los mismos； y la formulación ne
