Cortex is driven by weak but synchronously active thalamocortical synapses |
| |
| Authors: | Bruno Randy M Sakmann Bert |
| |
| Institution: | Department of Cell Physiology, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany. bruno@mpimf-heidelberg.mpg.de |
| |
| Abstract: | Sensory stimuli reach the brain via the thalamocortical projection, a group of axons thought to be among the most powerful in the neocortex. Surprisingly, these axons account for only approximately 15% of synapses onto cortical neurons. The thalamocortical pathway might thus achieve its effectiveness via high-efficacy thalamocortical synapses or via amplification within cortical layer 4. In rat somatosensory cortex, we measured in vivo the excitatory postsynaptic potential evoked by a single synaptic connection and found that thalamocortical synapses have low efficacy. Convergent inputs, however, are both numerous and synchronous, and intracortical amplification is not required. Our results suggest a mechanism of cortical activation by which thalamic input alone can drive cortex. |
| |
| Keywords: | |
| 本文献已被 PubMed 等数据库收录！ |
|
