Recovery of precision grasping after motor cortex lesion does not require forced use of the impaired hand in Macaca mulatta.

We investigated recovery of precision grasping of small objects between the index finger and thumb of the impaired hand without forced use after surgically placed lesions to the hand/arm areas of M1 and M1 + lateral premotor cortex in two monkeys. The unilateral lesions were contralateral to the monkey's preferred hand, which was established in prelesion testing as the hand used most often to acquire raisins in a foraging board (FB) task in which the monkey was free to use either hand to acquire treats. The lesions initially produced a clear paresis of the contralesional hand and use of only the ipsilesional hand to acquire raisins in the FB task.

Genetic control of interconnected neuronal populations in the mouse primary visual system.

Proliferation and survival of different cell types is thought to be modulated by cell interactions during development that achieve numerical and functional balance. We tested the precision of coregulation of numbers of neurons, glial cells, and endothelial cells in the dorsal lateral geniculate nucleus (LGN) in 58 isogenic strains of mice. We acquired matched counts of retinal ganglion cells (RGCs) in these strains and tested the precision of numerical matching between retina and LGN.