BDNF and metabolic syndrome: HFD intake resulted in dyslipidemia and hyperleptinemia, along with Aβ accumulation, tau hyperphosphorylation, α-synuclein elevation, and BDNF diminishment in the hippocampus, in addition to neurotransmitter and redox imbalance, heightened inflammation, and energy decline in the striatum and hippocampus with subsequent cognitive dysfunction.