The same brain cells linked to disorientation in Alzheimer’s disease have been preserved—and even slightly increased—across millions of years of evolution.
A new University of Michigan study suggests these neurons are vital to evolutionary survival. Nature has guarded and amplified them through countless generations, helping mammals instinctively know where they are in their environments. The research is published in The Journal of Neuroscience.
Researchers at the University of Seville have identified the possible origins of structural damage in the brains of patients with schizophrenia spectrum disorders (SSDs). These are regions that show the greatest morphological alterations in the early stages of the disease compared to neurotypical people of the same sex and age. The study also found that people with SSD have significant reductions in structural similarity between different regions of the temporal, cingulate and insular lobes.
The research is published in the journal Nature Communications.
The human brain is not a hard-wired machine but a malleable organ that is regularly re-shaping itself.
Neuroscientists at the University of Cambridge in the UK and the University of Pittsburgh in the US have now identified four major turning points in brain wiring between birth and death.
Like chapters of our lives, each of these neurological ‘epochs’ marks a new era of development or decline.
A central question in sensory neuroscience is how inputs from vision and touch are combined to generate cohesive representations of the external world. Here we reveal a widespread mode of brain organization in which aligned topographic maps bridge vision and somatosensation. We developed a computational model that revealed somatotopic structure in dorsolateral visual cortex. Somatotopic tuning in these regions was predictive of visual field locations more dorsally and visual body part selectivity more ventrally. These results suggest more extensive cross-modal overlap than traditionally assumed: the computational machinery classically attributed to the somatosensory system is also embedded within and aligned with that of the visual system. These aligned visual and bodily maps are a likely brain substrate for internalized somatosensory representations of visual signals, and are a candidate human homologue of findings in mice whereby somatomotor responses dominate visual cortex36.
Consistent with embodied perception theories, our model-based quantifications of somatotopic and retinotopic connectivity revealed that dorsolateral visual cortical responses to naturalistic stimuli are best explained by selectivities in both modalities, as opposed to visual selectivity alone. The necessity of incorporating body-referenced processing into models of dorsolateral visual cortex supports evidence that its role extends beyond passive visual analysis, encompassing perceptual, semantic and bodily functions optimized for behavioural interactions with the world25.
Consistent with visuospatial alignment of somatosensory tuning, we found that body part preferences in dorsolateral visual cortex predicted visual field tuning. Such alignment, previously reported at the terminus of the dorsal visual pathway around the postcentral sulcus28, therefore extends far into dorsal and lateral streams of the visual system. This alignment may be reinforced by shared developmental influences, as somatotopic and retinotopic maps are shaped trophically from birth: dorsal regions represent the upper body and visual field, and ventral regions to the lower body and visual field22, providing a roughly aligned sensory periphery optimized for efficient environmental sampling and action. The explicit interweaving of touch and retinal coordinates may subserve efficient perception of environmental affordances and a cohesive sense of spatial self-representation.