Recurrent long-lasting tethering reduces BDNF protein levels in the dorsal hippocampus and frontal cortex in pigs

► Tethering stress in sows reduced BDNF in the dorsal hippocampus and frontal cortex. ► Tethering stress increased TrkB in the dorsal hippocampus. ► Tethering effects on BDNF and TrkB were more pronounced after 4.5 years than 1.5 years. ► Plasma cortisol levels and adrenal weight were increased after recurrent tethering. ► Cortisol correlated with BDNF levels in the dorsal hippocampus and frontal cortex.