The regulatory role of the 5-hydroxytryptamine (5-HT) system in learning and memory has attracted
more and more attention. 5-HT neurons are one of the most important neurons in learning and memory research. The
release of 5-HT acts on various subtypes of pre-post-synaptic membrane receptors to perform their effector functions,
and especially the in-depth study of 5-HTergic neuron projection circuits will promote the exploration of learning and
memory. This paper reviewed the 5-HT receptors, 5-HTergic neuron activity levels, and 5-HTergic neuron projection
circuits involved in learning and memory, and provided a theoretical basis for the treatment of learning and memory
disorders.