Fentanyl is a potent, fast-acting synthetic opioid that has played a major role in the opioid overdose crisis in the United States for over five decades, with opioid-related deaths increasing sharply Show more
Fentanyl is a potent, fast-acting synthetic opioid that has played a major role in the opioid overdose crisis in the United States for over five decades, with opioid-related deaths increasing sharply in recent years. This study investigates the behavioral, histological, and molecular changes in the hippocampus of rats subjected to sub-acute fentanyl exposure. Two groups of rats were studied: one group received multiple fentanyl injections over approximately one week, while the control group received no fentanyl. A battery of behavioral tests related to memory and depression-including the Y-maze, shuttle box, tail suspension test, elevated plus maze, Barnes maze, Morris water maze, and forced swimming test-was administered. Electrophysiological assessments, including field potential recording and electromyography (EMG), were conducted to evaluate neural activity. Western blot analysis was performed to quantify the expression of brain-derived neurotrophic factor (BDNF) and RE1-silencing transcription factor (REST), while immunohistochemical analyses assessed hippocampal cellular alterations. Results showed that sub-acute fentanyl administration impaired behavioral performance in memory assessment tests (Y maze ( Show less