PACAP 1-27 is primarily involved in neuroprotective and neuromodulatory functions. It plays a key role in regulating neuronal survival and differentiation, making it a subject of interest in research on neurodegenerative conditions such as Parkinson’s and Alzheimer’s diseases. The peptide exhibits anti-inflammatory effects in the central nervous system, helping to reduce glial activation and cytokine release. It also influences synaptic transmission and plasticity, contributing to learning and memory processes. In addition, PACAP 1-27 has been studied for its role in protecting neurons from ischemic damage following stroke, due to its ability to suppress apoptosis and oxidative stress. Its involvement in circadian rhythm regulation and stress response further expands its potential therapeutic relevance in neurological and psychiatric disorders.