Active dendrites enable strong but sparse inputs to determine orientation selectivity
Lea Goetz, Arnd Roth, Michael Häusser
Abstract
Significance An active pyramidal cell model, constrained by physiological and anatomical data, was used to simulate dendritic integration in vivo. The model shows that small numbers of strong excitatory synapses can trigger dendritic Na + and NMDA spikes. Moreover, only a few dendritic spikes are sufficient to drive a single output action potential. As a consequence, as few as 1% of the synaptic inputs to a neuron can determine the tuning of somatic output in vivo. These results suggest that dendritic spikes can help to make sensory representations more efficient and flexible: they require fewer connections to sustain them, and only a small number of connections need to be changed to encode a different stimulus and alter the response properties of a neuron.