BDNF and neurodegenerative disease: It is noteworthy that in the development and progression of cognitive impairment‐related diseases, particularly neurodegenerative diseases, in addition to the neuroinflammation we focus on, 5‐HT7R can also play a critical role in maintaining and restoring cognitive function by regulating multiple mechanisms, including abnormal protein aggregation (such as Aβ deposition), synaptic dysfunction (such as impaired synaptic plasticity), mitochondrial dysfunction (such as oxidative stress), and dysregulation of neurotrophic factors (such as brain‐derived neurotrophic factor) [47].