Currents contributing to decision making in neurons B31-B32 of Aplysia (Hurwitz et al. 2008)

"Biophysical properties of neurons contributing to the ability of an animal to decide whether or not to respond were examined. B31/B32, two pairs of bilaterally symmetrical Aplysia neurons, are major participants in deciding to initiate a buccal motor program, the neural correlate of a consummatory feeding response. B31/B32 respond to an adequate stimulus after a delay, during which time additional stimuli influence the decision to respond. B31/B32 then respond with a ramp depolarization followed by a sustained soma depolarization and axon spiking that is the expression of a commitment to respond to food. Four currents contributing to decision making in B31/B32 were characterized, and their functional effects were determined, in current- and voltage-clamp experiments and with simulations. ... Hodgkin-Huxley kinetic analyses were performed on the outward currents. Simulations using equations from these analyses showed that IK-V and IK-A slow the ramp depolarization preceding the sustained depolarization. The three outward currents contribute to braking the B31/B32 depolarization and keeping the sustained depolarization at a constant voltage. The currents identified are sufficient to explain the properties of B31/B32 that play a role in generating the decision to feed."

Model Type: Neuron or other electrically excitable cell

Region(s) or Organism(s): Aplysia

Cell Type(s): Aplysia B31/B32 neuron

Currents: I Na,t; I A; I K

Model Concept(s): Action Selection/Decision Making

Simulation Environment: SNNAP

References:

Hurwitz I, Ophir A, Korngreen A, Koester J, Susswein AJ. (2008). Currents contributing to decision making in neurons B31/B32 of Aplysia. Journal of neurophysiology. 99 [PubMed]