PDYN and epilepsy: To achieve the aims of this critical review, data was sourced from online databases including Google Scholar, PubMed, Science Direct, and Web of science with a particular focus on recent research [Example search terms included: (“opioids” OR “dynorphin” AND “microglia” OR “epilepsy”) and (“microglia” OR “opioids” AND “proconvulsant” OR “anticonvulsant” OR “epilepsy” OR “neuroprotective”)].