[Structure and Function of Thalamocortical Circuits Underlying Alloparental Behaviors]

The thalamus is widely recognized as a major source of input to the cerebral cortex and extensive knowledge of its anatomical connectivity has been accumulated through classical tracer studies. However, the quantitative characteristics of the thalamocortical connections and their physiological functions remain poorly understood. This issue is particularly important for higher-order cortical areas, such as the prefrontal cortex, which lack the prominent layer-4 bottom-up input characteristics of sensory cortices, raising the unresolved question of what types of inputs underlie higher cognitive functions. Moreover, the presence of anatomical connections alone does not directly reveal which information is transmitted or how strongly it is conveyed in functional terms. This review focuses on parental behavior, a form of social behavior shaped by the complex interaction between learning and innate processes, and summarizes recent findings on the anatomical organization and physiological functions of the thalamocortical circuits formed between the orbitofrontal cortex and its thalamic partners.