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. 2007 Jun 1;70(10):1753-1758.
doi: 10.1016/j.neucom.2006.10.117.

Decoding modulation of the neuromuscular transform

Estee Stern  1 , Timothy J Fort, Mark W Miller, Charles S Peskin, Vladimir Brezina
Affiliations

Decoding modulation of the neuromuscular transform

Estee Stern et al. Neurocomputing (Amst). .

Abstract

When modulators of neuromuscular function alter the motor neuron spike patterns that elicit muscle contractions, it is predicted that they will also retune correspondingly the connecting processes of the neuromuscular transform. Here we confirm this prediction by analyzing data from the cardiac neuromuscular system of the blue crab. We apply a method that decodes the contraction response to the spike pattern in terms of three elementary building-block functions that completely characterize the neuromuscular transform. This method allows us to dissociate modulator-induced changes in the neuromuscular transform from changes in the spike pattern in the normally operating, essentially unperturbed neuromuscular system.

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Figures

Fig. 1
Fig. 1
The question. K, H, and F are the functions that characterize the neuromuscular transform in our analysis.
Fig. 2
Fig. 2
The data, from a representative semi-intact working heart preparation [6, 7] of Callinectes. A, top: heart muscle tension. A, bottom: cardiac ganglion motor neuron spike pattern, recorded extracellularly in a connective leading from the ganglion to the muscle. 10−6 M CCAP was superfused; the lag before the response reflects the dead volume of the perfusion system. B and C expand the unmodulated and modulated excerpts in the small boxes in A. The large boxes in A indicate the unmodulated (175 s of data, with 466 spikes) and modulated (100 s of data, with 740 spikes) portions of data that were used to decode, respectively, the unmodulated and modulated functions K, H, and F in Fig. 3.
Fig. 3
Fig. 3
The unmodulated (open circles) and modulated (filled circles) functions K, H, and F decoded from the portions of data within the large boxes in Fig. 2A.
Fig. 4
Fig. 4
Representative contraction waveforms reconstructed by passing the unmodulated (A) and modulated (B) spike patterns shown in row 1 (taken from Fig. 2) through the unmodulated (row 3) and modulated (row 4) functions K, H, and F. The contraction waveforms that were really observed are shown in row 2. Note different time scales in A and B.
Fig. 5
Fig. 5
Statistics of the reconstruction of the entire dataset. A: root mean square (RMS) error between the real contraction waveform Rexp and the reconstructed contraction waveform Rest when a reconstruction like that in Fig. 4 was performed for each successive 5 s-long segment of the data in Fig. 2A with either the unmodulated (open points) or the modulated (filled points) functions K, H, and F. The continuous curves are simply smoothed curves through the points to show their average trend. The boxes are reproduced from Fig. 2A to indicate the portions of the data from which the unmodulated and modulated functions K, H, and F were decoded. B: means ± SE of the RMS errors from A, comparing four conditions: unmodulated spike pattern segments reconstructed with the unmodulated functions K, H, and F (bar 1) and with the modulated functions (bar 2), and modulated spike pattern segments reconstructed with the unmodulated functions (bar 3) and with the modulated functions (bar 4). Specifically, the points included in the appropriate bars of B were all those lying within the boxes in A. Statistical significance was tested with ANOVA on ranks followed by pairwise multiple comparisons using the Holm-Sidak method; “***” indicates p < 0.001.
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References

    1. Brezina V, Orekhova IV, Weiss KR. The neuromuscular transform: the dynamic, nonlinear link between motor neuron firing patterns and muscle contraction in rhythmic behaviors. J Neurophysiol. 2000;83:207–231. - PubMed
    1. Brezina V, Orekhova IV, Weiss KR. Optimization of rhythmic behaviors by modulation of the neuromuscular transform. J Neurophysiol. 2000;83:260–279. - PubMed
    1. Brezina V, Weiss KR. The neuromuscular transform constrains the production of functional rhythmic behaviors. J Neurophysiol. 2000;83:232–259. - PubMed
    1. Calabrese RL. Modulation of muscle and neuromuscular junctions in invertebrates. Semin Neurosci. 1989;1:25–34.
    1. Cooke IM. Reliable, responsive pacemaking and pattern generation with minimal cell numbers: the crustacean cardiac ganglion. Biol Bull. 2002;202:108–136. - PubMed

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