Computational models of self-organizing neural networks and associative memory depend on hebbian synaptic plasticity, a local learning rule for increasing synaptic strengths based on coincident electrical activity in presynaptic and postsynaptic neurons. Some forms of long-term potentiation (L TP) studied in the hippocampus and neocortex are hebbian. Learning rules in network models also incorp...

Over 50% of the non-human primate neocortex is involved in visual processing, compared to about 11% for somatosensory, 8% for motor, and 3% for . The visual processing takes place in many different areas auditory processing of neocortex and they are connected together in a hierarchy. The primary visual cortex, which receives the earliest visual input, comprises less than 10% of the cortex (10 n...

The hallmark of the cerebral neocortex is its organization into six layers, each containing a characteristic set of cell types and synaptic connections. The transcriptional events involved in laminar development and function still remain elusive. Here, we employed deep sequencing of mRNA and small RNA species to gain insights into transcriptional differences among layers and their temporal dyna...

Human cognition is thought to be mediated by large-scale interactions between distant sites in the neocortex. Synchronization between different cortical areas has been suggested as one possible mechanism for corticocortical interaction. Here, we report robust, directional cross-frequency synchronization between distant sensorimotor sites in human neocortex during a movement task. In four subjec...

The thalamocortical tract carries sensory information to the neocortex. It has long been recognized that the neocortical pioneer axons of subplate neurons are essential for thalamocortical development. Herein we report that an axon guidance cue, draxin, is expressed in early-born neocortical neurons, including subplate neurons, and is necessary for thalamocortical development. In draxin(-/-) mi...

We have considered how the neuronal network architecture of the hippocampus may enable it to act as an intermediate term buffer store for recent memories, and how information may be recalled from it to the cerebral cortex using modified synapses in back-projection pathways from the hippocampus to the cerebral cortex. The recalled information in the cerebral neocortex could then be used by the n...

Recent studies have established a relationship between the repertoire of signals used for communication and neocortex size of different species of primates and the topology of the social network formed by the interactions between individuals. Inspired by these results, we have developed a model that qualitatively reproduces these observations. The model presents the social organization as a sel...