IRS1 and obesity due to melanocortin 4 receptor deficiency: Swimming intervention can reverse these abnormal changes to rescue the impaired learning and memory capacity in obese mice by reducing obesity, alleviating hippocampal neuroinflammation, activating insulin signaling, promoting the generation and secretion of neurotrophic factors, and suppressing hippocampal neuronal apoptosis in adolescent mice, with the involvement of the JNK/IRS-1/PI3K/Akt and PGC-1α/BDNF signal pathways (Figure 8).