[The review of 'Yakovlev' circuit]

The neuronal circuit, the so-called 'Yakovlev', is recognized as the neuronal connections between the orbitofrontal, temporal, amygdaloid, and thalamic regions, possibly relevant to emotional function. This name is well known in Japan, however, it is not clear how this neural circuit has become known and why it was named after Yakovlev. Yakovlev, himself, just emphasized the relationship between emotion and the limbic lobes. It might be Nauta who first clarified the circuitry connections between these structures. Then, it was named the 'basolateral limbic circuit' by Livingston. The reason that the circuit had been called 'Yakovlev' might be related to this reference by Livingston who associated the circuit with the hypothesis of limbic system and emotion by Yakovlev. Recent sophistication in tracing methods has clarified the minimal contribution of the anterior cingulate gyrus to this circuit and that the projection from the amygdala to thalamus is unidirectional It will then be more appropriate to define this circuit as follows: orbital and cingulate gyri<=> temporal tip<=> amygdala=> mediodorsal thalamus<=> orbital and cingulate gyri. Yakovlev contributed greatly to identifying the possible relevance of these structures to emotion, which was substantiated by Nauta with his anatomical tracing between the structures. The name of this circuit, 'Yakovlev', would be better modified to 'Yakovlev-Nauta'.