Systems NeuroscienceResearch PaperLocomotor networks are targets of modulation by sensory transient receptor potential vanilloid 1 and transient receptor potential melastatin 8 channels
Section snippets
Experimental procedures
Experiments were performed on Swiss Webster mice (Charles River Laboratories, Senneville, Quebec, Canada), transient receptor potential vanilloid 1-null mice (trpv1−/−) (B6.129X1-Trpv1tm1Jul/J, The Jackson Laboratory, Bar Harbor, Maine, USA), transient receptor potential melastatin 8-null mice (trpm8−/−) (generated as described in; Dhaka et al., 2007). Mice used for all experiments in the study were between postnatal days (P) 0 and P3. The animals were anesthetized by hypothermia, decapitated
TRPV1 modulates SCA evoked locomotor rhythm
To address whether modulation of subclasses of C and Aδ afferent inputs alters the excitability of spinal motor circuits, we used a stimulus paradigm which activated SCA (Lev-Tov et al 2000, Whelan et al 2000). These afferents likely synapse onto interneurons which project directly or indirectly into the ventrolateral funiculus (VLF) and in turn onto the lumbar CPG (Fig. 2C) (Strauss and Lev-Tov, 2003). We activated the subclass of TRPV1-positive C and Aδ afferents in the SCA pathway by using
Discussion
The goal of this study was to identify the role of distinct somatosensory and nociceptive afferents in the control of locomotion and to describe a set of tools to effectively do so using isolated spinal cord preparations. To accomplish this, we focused on the modulation of thermoTRPs, which underlie the transduction of hot and cold sensation in the skin (Venkatachalam and Montell, 2007). These receptors are located both in the peripheral and central terminals of afferents (Julius and Basbaum
Acknowledgments
We would like to thank Michelle Tran for her excellent technical assistance. We greatly appreciate ongoing support from the Alberta Heritage Foundation for Medical Research, the Canadian Institutes of Health Research, and the University of Calgary. Dr. Sravan Mandadi was supported by a fellowship from the Alberta Heritage Foundation for Medical Research. Dr. Stan Nakanishi was supported by a fellowship from the Hotchkiss Brain Institute.
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