ABSTRACT
This chapter explores the clinical literature for evidence that there may exist in the thalamocingulate division of the limbic system a reciprocal innervation of crying and laughter. In contradistinction to the positive effects of limbic cortical ablation, it is notable that in a case involving aspiration of all of the midline frontal neocortex there was no effect on the spontaneous production of the separation cry. The use of improved neuroanatomical techniques has thrown a whole new light on connections of the frontal cortex with the thalamus. Using autoradiographic techniques involving axoplasmic transport, T. J. Tobias appears to have been the first to show that the medial dorsal nucleus does indeed project to the dorsal medial granular cortex of the frontal lobe. The new anatomical findings, together with clinical data, suggest a linkup of frontal lobe and striopallidonigral mechanisms implicated in both the mood and expression of crying and laughter.
