Contribution of Single Synapses to Sensory Representation in Vivo

• Published in: Science (American Association for the Advancement of Science) Vol. 321; no. 5891; pp. 977 - 980
• Main Authors: Arenz, Alexander, Silver, R. Angus, Schaefer, Andreas T, Margrie, Troy W
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 15.08.2008; The American Association for the Advancement of Science
• Subjects: Amplitude; Angular velocity; Animals; Biological and medical sciences; Cellular biology; Cerebellum; Cerebellum - cytology; Cerebellum - physiology; Excitatory Postsynaptic Potentials; Fundamental and applied biological sciences. Psychology; General aspects. Models. Methods; Information representations; Kinetics; Mental stimulation; Mice; Nerve Fibers - physiology; Neurology; Neurons; Neurons - physiology; Patch-Clamp Techniques; Purkinje cells; Rotation; Sensory perception; Synapses; Synapses - physiology; Velocity; Vertebrates: nervous system and sense organs; Vestibule, Labyrinth - physiology; Cerebellum; Motion; Frequency modulation; Stimulus; Granule neuron; Central nervous system; Electrophysiology; Representation; Encephalon; Synapse; Excitatory postsynaptic current; Acceleration; Charge transfer
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.1158391

The extent to which synaptic activity can signal a sensory stimulus limits the information available to a neuron. We determined the contribution of individual synapses to sensory representation by recording excitatory postsynaptic currents (EPSCs) in cerebellar granule cells during a time-varying, quantifiable vestibular stimulus. Vestibular-sensitive synapses faithfully reported direction and velocity, rather than position or acceleration of whole-body motion, via bidirectional modulation of EPSC frequency. The lack of short-term synaptic dynamics ensured a highly linear relationship between velocity and charge transfer, and as few as 100 synapses provided resolution approaching psychophysical limits. This indicates that highly accurate stimulus representation can be achieved by small networks and even within single neurons.