2007/01/04 by Nathan Cramer, Ying Li, Asaf Keller · 1 citation
Biochemistry, Genetics and Molecular Biology · Neuroscience · Psychology · #Zebrafish Biomedical Research Applications #Neurobiology and Insect Physiology Research #Neural dynamics and brain function #Whisking in animals #Rhythm #Movement (music) #Neuroscience #Communication #Central pattern generator #Generator (circuit theory) #Computer science #Psychology #Physics #Sensory system #Power (physics)
paper · doi:10.1152/jn.01187.2006
openalex publication_date 2007/01/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Using the rat vibrissa system, we provide evidence for a novel mechanism for the generation of movement. Like other central pattern generators (CPGs) that underlie many movements, the rhythm generator for whisking can operate without cortical inputs or sensory feedback. However, unlike conventional mammalian CPGs, vibrissa motoneurons (vMNs) actively participate in the rhythmogenesis by converting tonic serotonergic inputs into the patterned motor output responsible for movement of the vibrissae. We find that, in vitro, a serotonin receptor agonist, alpha-Me-5HT, facilitates a persistent inward current (PIC) and evokes rhythmic firing in vMNs. Within each motoneuron, increasing the concentration of alpha-Me-5HT significantly increases the both the magnitude of the PIC and the motoneuron's firing rate. Riluzole, which selectively suppresses the Na(+) component of PICs at low concentrations, causes a reduction in both of these phenomena. The magnitude of this reduction is directly correlated with the concentration of riluzole. The joint effects of riluzole on PIC magnitude and firing rate in vMNs suggest that the two are causally related. In vivo we find that the tonic activity of putative serotonergic premotoneurons is positively correlated with the frequency of whisking evoked by cortical stimulation. Taken together, these results support the hypothesized novel mammalian mechanism for movement generation in the vibrissa motor system where vMNs actively participate in the rhythmogenesis in response to tonic drive from serotonergic premotoneurons.