Abstract
In the previous paper, we described a model of the elemental heartbeat oscillator in the leech. Here, the parameters of our model are explored around the baseline canonical model. The maximal conductances of the currents and the reversal potential of the leak current are varied to reveal the effects of individual currents and the interaction between synaptic and intrinsic currents in the model. The model produces two distinct modes of oscillation as the parameters are varied, S-mode and G-mode. These two modes are defined, their origin is identified, and the parameter space is mapped into S-mode and G-mode oscillation and no oscillation. Finally, we will make predictions for how the period can be modulated in heart interneurons.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Angstadt JD, Calabrese RL (1989) A hyperpolarization-activated inward current in heart interneurons of the medicinal leech.J. Neurosci. 9:2846–2857.
Angstadt JD, Calabrese RL (1991) Calcium currents and graded synaptic transmission between heart interneurons of the leech.J. Neurosci. 11:746–759.
Arbas EA, Calabrese RL (1984) Rate modification in the heartbeat central pattern generator of the medicinal leech.J. Comp. Physiol. A 155:783–794.
Arbas EA, Calabrese RL (1990) Leydig neuron activity modulates the heart-beat in the medicinal leech.J. Comp. Physiol. A 167:665–671.
Calabrese RL, De Schutter E (1992) Motor-pattern-generating networks in invertebrates: Modeling our way toward understanding.TINS 15:439–445.
De Schutter E, Angstadt JD, Calabrese RL (1993) A model of graded synaptic transmission for use in dynamic network simulations.J. Neumphysiol 69:1225–1235.
Evans BD, Pohl J, Kartsonis NA, Calabrese RL (1991) Identification of RFamide neuropeptides in the medicinal leech.Peptides 12:897–908.
Golowasch J, Marder E (1992) Ionic currents of the lateral pyloric neuron of the stomatogastric ganglion of the crab.J. Neumphysiol. 67:318–331.
Harris-Warrick RM, Marder E (1991) Modulation of Neural Networks for Behaviour.Ann. Rev. Neurosci. 14:39–57.
Hooper SL, Marder E (1987) Modulation of the lobster pyloric rhythm by the peptide proctolin.J. Neurosci. 7:2097–2112.
Kuhlman JR, Li C, Calabrese RL (1985) FMRF-amide-like substances in the leech.J. Neurosci. 4:2310–2317.
Li C, Calabrese RL (1987) FMRF-amide-like substances in the leech. III. Biochemical characterization and physiological effects,J. Neurosci. 7:595–603.
Marder E (1991) Plateaus in time.Current Biology 1:326–327.
Nadim F, Olsen ØH, De Schutter E, Calabrese RL (1995), Modeling the leech heartbeat elemental oscillator: I. Interactions of intrinsic and synaptic currents,J. Comp. Neurosci. 2:215–235.
Opdyke CA, Calabrese RL (1994) A persistent sodium current contributes to oscillatory activity in heart interneurons of the medicinal leech.J. Comp. Physiol. A 175:781–789.
Peterson EL (1983) Generation and coordination of heartbeat timing oscillation in the medicinal leech. II. Intersegmental coordination,J. Neumphysiol. 49:626–638.
Simon TW, Opdyke CA, Calabrese RL (1992) Modulatory effects of FMRF-NH2 on outward currents and oscillatory activity in heart interneurons of the medicinal leech.J. Neurosci. 12:525–537.
Simon TW, Schmidt J, Calabrese RL (1994) Modulation of high-threshold transmission between heart interneurons of the medicinal leech by FMRF-NH2.J. Neurophysiol. 71:454–466.
Skinner FK, Kopell N, Marder K (1994) Mechanisms for oscillation and frequency control in reciprocally inhibitory model neural networks.J. Comp. Neurosci. 1:69–87.
Wang X-J, Rinzel J (1992) Alternating and synchronous rhythms in reciprocally inhibitory model neurons.Neural Comp. 4:84–97.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Olsen, Ø.H., Nadim, F. & Calabrese, R.L. Modeling the leech heartbeat elemental oscillator II. Exploring the parameter space. J Comput Neurosci 2, 237–257 (1995). https://doi.org/10.1007/BF00961436
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00961436