Cortex is driven by weak but synchronously active thalamocortical synapses.

Supporting Online Material for Cortex is Driven by Weak but Synchronously Active Thalamocortical Synapses

Neuroscience. Neurons find strength through synchrony in the brain.

F or any touch, sound, or image to be perceived, our senses have to activate neurons at the very center of the brain, in the thalamus. In turn, thalamic neurons must activate neurons in the cerebral cortex, where most complex brain functions take place. One would think that, given their role in sensory processing, the connections between the thalamus and cortex would be strong and reliable. Aft...

Thalamocortical connections of the primary somatosensory cortex

  Although each subdivision of primary somatosensory cortex (SI) receives dense input from the thalamus, but the exact location and type of information that the fibers convey have not been identified yet. In the present study, the exact source of thalamocortical fibers to areas 2 and 3b was investigated using tract-tracing techniques. Following injection of tracer into area 3b, labeled neurons ...

Experience-Dependent, Layer-Specific Development of Divergent Thalamocortical Connectivity

The main input to primary sensory cortex is via thalamocortical (TC) axons that form the greatest number of synapses in layer 4, but also synapse onto neurons in layer 6. The development of the TC input to layer 4 has been widely studied, but less is known about the development of the layer 6 input. Here, we show that, in neonates, the input to layer 6 is as strong as that to layer 4. Throughou...

The Histological Evidences for Developmental Alternations in the Transmitting Time of Impulses along the Thalamocortical Tract

Change in transmitting time of impulses along axons is traditionally attributed to two parameters: the myelin formation and the diameter of neurite, both rising during the postnatal development. In the previous study, we showed that conduction velocity of the fibers projecting from the thalamus to the layer IV of the somatosensory (barrel) cortex increases as a function of age. However, the con...