The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptor (PAC1) are widely distributed in the central nervous system. Although it has been reported that PACAP-PAC1 signaling contributes to learning and memory, it is not clear what mechanism is involved in neuroplasticity. In this study, we investigated the involvement of PACAP-PAC1 signaling in astrocytes for working memory. First, to confirm the expression of PAC1 in hippocampal astrocytes, we obtained astrocyte-specific mRNA using the Ribo-tag method, and RT-qPCR revealed that astrocytes expressed PAC1 six times higher than all cell types. A selective knockout of hippocampal astrocytic PAC1 resulted in the impaired working memory of the Y-maze test. To investigate the origin of PACAP neurons projecting to hippocampal astrocytes, we infected the hippocampus of PACAP-Cre mice with adeno-associated virus (AAV), which is retrogradely transported and expresses mCherry in a Cre-dependent manner, and observed mCherry-positive cells. We found some mCherry-positive cells in the rhinal cortex. Furthermore, we infected the rhinal cortex of PACAP-cre mice with AAV, which expresses a synaptophysin-EGFP chimeric protein cre-dependently. We found many synaptophysin-EGFP positive punctate around hippocampal astrocytes, suggesting PACAP neurons in the rhinal cortex sent axons to the hippocampal astrocytes. These findings suggested that PACAP from the rhinal cortex might act on hippocampal astrocytic PAC1 and contribute to the working memory.