Monocular deprivation (MD) during the critical period (CP) shifts ocular dominance (OD) of cortical responsiveness toward the nondeprived eye. The synaptic mechanisms underlying MD-induced OD plasticity, in particular the contribution of cortical inhibition to the plasticity, have remained unsolved. In this study, using in vivo whole-cell voltage-clamp recordings, we revealed eye-specific excit...

Recent studies have shown that ocular dominance plasticity in layer 2/3 of the visual cortex exhibits a form of homeostatic plasticity that is related to synaptic scaling and depends on TNFα. In this study, we tested whether a similar form of plasticity was present in layer 2/3 of the barrel cortex and, therefore, whether the mechanism was likely to be a general property of cortical neurons. We...

Monocular deprivation evokes a prominent shift of neuronal responses in the visual cortex toward the open eye, accompanied by functional and structural synaptic rearrangements. This shift is reversible, but it is unknown whether the recovery happens at the level of individual neurons or whether it reflects a population effect. We used ratiometric Ca(2+) imaging to follow the activity of the sam...

Monocular visual deprivation (MD) produces profound changes in the ocular dominance (OD) of neurons in the visual cortex. MD shifts visually evoked responses away from the deprived eye and toward domination by the open-eye. Over 30 years ago, two different theories were proposed to account for these changes: either through effects on excitatory visual drive, thereby shifting the balance of exci...

Recent electrophysiological studies of rodent visual cortex suggest that, in addition to deprived-eye depression, monocular deprivation (MD) also shifts ocular dominance by potentiation of open-eye responses. We used computer-based, two-choice discrimination tasks to assess the behavioral significance of these findings in rats. As expected, prolonged MD, from postnatal day 21 until adulthood (>...

Developmental disorders of reading and spelling have long been associated with increased left- and mixed-handedness but the evidence has been controversial. The right shift (RS) theory of handedness and cerebral dominance, developed by Annett from 1972 onward, offers resolutions to several puzzles about laterality in the so-called dyslexias. This review of findings in the light of the theory sh...

A 78 year old, right handed man developed the syndrome of alexia without agraphia due to a right occipital thrombotic stroke. The cerebral dominance test strongly suggests that his right hemisphere is dominant. This is believed to be the first case of alexia without agraphia secondary to a right occipital lesion in a right handed person.

Experience can dramatically alter the responses of cortical neurons. During a critical period in the development of visual cortex, these changes are extremely rapid, taking place in 2 d or less. Anatomical substrates of these changes have long been sought, primarily in alterations in the principal visual input from the thalamus, but the significant changes that have been found take 1 week. Rece...

In humans, handedness is one defining characteristic regardless of cultures and ethnicity. Population-level right handedness is considered to be related with the evolution of left hemisphere for manual control and language. In order to further understand evolutionary origins of human cerebral lateralization and its behavioral adaptation, standardized measures on hand preference are required to ...