The majority of synapses in the mammalian cortex originate from cortical neurons. Indeed,
the largest input to cortical cells comes from neighboring excitatory cells. However, most …

The efficacy and short-term modification of neocortical synaptic connections vary with the
type of target neuron. We investigated presynaptic Ca2+ and release probability at single …

The microcircuitry of the mammalian neocortex remains largely unknown. Although the
neocortex could be composed of scores of precise circuits, an alternative possibility is that …

The mammalian neocortex consists of a mosaic of columnar units whose development is
poorly understood. Optical recordings of brain slices labeled with the fluorescent calcium …

One of the basic functions of the cerebral cortex is the analysis and representation of
relations among the components of sensory and motor patterns. It is proposed that the cortex …

BACKGROUND The human brain contains about 100 billion neurons, each of which makes
thousands of synaptic connections. Although individual neurons can themselves be …

The functional architecture of synaptic circuits is determined to a crucial degree by the
patterns of electrical activity that occur during development. Studies with an in vitro …

In the visual cortex of the brain, long-ranging tangentially oriented axon collaterals
interconnect regularly spaced clusters of cells. These connections develop after birth and …

Correlated trial-to-trial variability in the activity of cortical neurons is thought to reflect the
functional connectivity of the circuit. Many cortical areas are organized into functional …

It is not known whether the variability of neural activity in the cerebral cortex carries
information or reflects noisy underlying mechanisms. In an examination of the reliability of …