An electrochromic dye was used to make fast, high signal/noise ratio, linear scale optical measurements of membrane potential from spines and basal dendrites of mouse somatosensory cortex layer 5 pyramidal cells. These experiments revealed close electrical coupling, with little signal loss, for membrane potential spreading from the spine head to the adjacent dendritic shaft. Modeling was used to explore the relationship between cellular properties (anatomy and biophysics) and the degree of electrical coupling between spines and dendrites. For usage instructions, see readme.pdf
Experimental motivation: The model omitted voltage-gated channels because they were pharmacologically blocked in the experiments that constrained the modeling. This does not alter the main findings of this paper because spine neck resistance depends on cytoplasmic resistivity and the geometry of the spine neck, not on membrane properties.
Model Type: Neuron or other electrically excitable cell
Region(s) or Organism(s): Mouse
Cell Type(s): Neocortex layer 5 pyramidal cell
Currents:
Receptors:
Genes:
Transmitters:
Model Concept(s): Electrotonus; Synaptic Integration; Two-port analysis of electrotonus; Voltage transfer ratio
Simulation Environment: NEURON
References:
Popovic MA, Carnevale N, Rozsa B, Zecevic D. (2015). Electrical behaviour of dendritic spines as revealed by voltage imaging. Nature communications. 6 [PubMed]