Crossed Connections From Insular Cortex to the Contralateral Thalamus

Sensory information in all modalities, except olfaction, is processed at the level of the thalamus before subsequent transmission to the cerebral cortex. This incoming sensory stream is refined and modulated in the thalamus by numerous descending corticothalamic projections originating in layer 6 that ultimately alter the sensitivity and selectivity for sensory features. In general, these sensory thalamo-cortico-thalamic loops are considered strictly unilateral, i.e., no contralateral crosstalk between cortex and thalamus. However, in contrast to this canonical view, we characterize here a prominent contralateral corticothalamic projection originating in the insular cortex, utilizing both retrograde tracing and cre-lox mediated viral anterograde tracing strategies with the Ntsr1-Cre transgenic mouse line. From our studies, we find that the insular contralateral corticothalamic projection originates from a separate population of layer 6 neurons than the ipsilateral corticothalamic projection. Furthermore, the contralateral projection targets a topographically distinct subregion of the thalamus than the ipsilateral projection. These findings suggest a unique bilateral mechanism for the top-down refinement of ascending sensory information.

Bilateral Solutions

In this chapter, I highlight how the administrative response to the immediate fallout of the partition, was determined foremost by how it could be bilaterally handled, rather than being governed by any other consideration—including, for instance, the necessity of bringing immediate relief to the law and order question. I examine how the Partition Council approached the question of setting up the foreign ministries for India and Pakistan in August, 1947, and the importance that was given to having a diplomatic architecture in place that could handle the inter-face between India and Pakistan on issues relating to abducted women, and the Punjab Boundary Force. In many ways, notwithstanding the glaring inadequacies of the state apparatus in being able to contain the violence around partition, what was given importance was the ability to produce a bilateral mechanism to deal with partition’s fallout.