Evidence suggests rhythmic whisker movements in rats are driven by a subcortical central pattern generator (CPG) under control of the whisker motor cortex (wMCx). Additionally, it has been demonstrated that serotonin (5HT) is necessary for whisking. My goal is to investigate a subset of 5HT neurons in the brainstem of adult rats that are likely to comprise an integral part of the whisking CPG. I will investigate the control exerted by the wMCx over this putative CPG component and the impact that the resulting CPG modulation has on whisking frequencies. I propose that the 5HT CPG determines firing frequency of whisker motor units by regulating the delivery of 5HT to motoneurons in the lateral facial nucleus. I further propose that 5HT regulates motor unit firing rates by facilitating a persistent inward current in whisker motoneurons (wMNs) in a dose dependent manner. I will investigate the ability of 5HT to facilitate a dose dependent PIC in whisker motoneurons and its relation to whisker motoneuron firing frequency. ? ? ?
| Cramer, Nathan P; Li, Ying; Keller, Asaf (2007) The whisking rhythm generator: a novel mammalian network for the generation of movement. J Neurophysiol 97:2148-58 |
| Cramer, Nathan P; Keller, Asaf (2006) Cortical control of a whisking central pattern generator. J Neurophysiol 96:209-17 |
| Friedman, Wendy A; Jones, Lauren M; Cramer, Nathan P et al. (2006) Anticipatory activity of motor cortex in relation to rhythmic whisking. J Neurophysiol 95:1274-7 |
