there are some conflicts about constancy of conduction velocity (cv) in a given tract of nervous system. by recording excitatory postsynaptic currents (epsc) in layer iv of the somatosensory cortex we tried to clear changes in cv of thalamocortical tract of mice aged 3 to 50 days old. field potentials and epsc were recorded in the layer iv by stimulation of ventrobasal nucleus of thalamus (vb) ...

Early events in the formation of the thalamocortical tract remain poorly understood. Recent work has suggested that thalamocortical axons follow a path pioneered by transient thalamic afferents originating from the medial part of the ventral telencephalon. We studied the development of these transient afferents and the thalamocortical tract in mutant mice lacking transcription factors normally ...

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...

There are some conflicts about constancy of conduction velocity (CV) in a given tract of nervous system. By recording excitatory postsynaptic currents (EPSC) in layer IV of the somatosensory cortex we tried to clear changes in CV of thalamocortical tract of mice aged 3 to 50 days old. Field potentials and EPSC were recorded in the layer IV by stimulation of ventrobasal nucleus of thalamus (VB) ...

Background: The mammalian thalamus relays sensory information from the periphery to the cerebral cortex for cognitive processing via the thalamocortical tract. The thalamocortical tract forms during embryonic development controlled by mechanisms that are not fully understood. b-catenin is a nuclear and cytosolic protein that transduces signals from secreted signaling molecules to regulate both ...

Thalamic interneurons and thalamic reticular nucleus (TRN) neurons provide inhibitory innervation of thalamocortical cells that significantly influence thalamic gating. The local interneurons in the dorsal lateral geniculate nucleus (dLGN) give rise to two distinct synaptic outputs: classical axonal and dendrodendritic. Activation of metabotropic glutamate receptors (mGluRs) by agonists or opti...

Neuronal migration and axon guidance constitute fundamental processes in brain development that are generally studied independently. Although both share common mechanisms of cell biology and biochemistry, little is known about their coordinated integration in the formation of neural circuits. Here we show that the development of the thalamocortical projection, one of the most prominent tracts i...

In the vertebrate brain, the thalamus serves as a relay and integration station for diverse neuronal information en route from the periphery to the cortex. Formation of the thalamocortical tract occurs during pre- and postnatal development, with distinct thalamic nuclei projecting to specific cortical regions. The molecular forces that underlie the invasion by axons into specific cortical layer...

embryogenesis, the ventral telencephalon (VT) plays a major role in the early development of these tracts. First, two populations of pioneer neurons allow corticothalamic (CTA) and thalamocortical axons (TCA) to enter the VT. Secondly, the VT forms a permissive corridor which guides TCAs through the MGE. Finally, thalamortical and corticothalamic axons guide each other once they have met in the...

  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 ...