S7-1.1.1 Jan. 6 Changing Speeds in a Central Pattern Generator SATTERLIE, Richard; University of North Carolina Wilmginton firstname.lastname@example.org
Several common threads run through the fabric of central pattern generator networks, including those at the circuit level, such as reciprocal inhibition, at the cellular level, such as postinhibitory rebound, and at the molecular level, such as specific ion currents that regulate the timing and stability of rhythmic activity. Similarly, changes in locomotory speed also involve alterations in all three of these CPG “levels.” At the circuit level, reorganization of CPG circuitry and recruitment of motoneurons (and muscle fiber types) create changes in both the frequency and intensity of limb movements. In addition, modulation of specific ion currents leads to changes in cellular properties, such as baseline depolarization of CPG interneurons and alterations in their postinhibitory rebound properties. Additional changes in ion currents may also help maintain the timing of mid-cycle inhibition in the face of an increase in cycle frequency. All of these examples are found in a model system used to investigate locomotory speed changes at circuit, cellular, and molecular levels—the swim system of the pteropod mollusk, Clione limacina.