seminars & bulletins

2014-2015
PBIO SEMINAR SERIES

THURSDAYS in G-328
10:30am (unless otherwise noted)
Refreshments follow the seminar

PBIO News

PBIO Special Events

Health Sciences Bulletin

Seminar Series archives

PBIO SEMINAR SERIES

Location: HSB G-328, 10:30am (unless otherwise noted)

February 13, 2014

"Spinal microcircuits in fish suggest an evolutionary template for limb control"

Martha Bagnall, Ph.D. , Northwestern University

Host: Stan Froehner

The evolutionary transition from the simple swimming rhythms of fish to more complicated motor patterns of tetrapods implies a major diversification of locomotor circuitry in the spinal cord. It remains unclear how axial spinal circuits for left/right alternation could have given rise to complex tetrapod networks required for walking. Using physiological recordings from motor neuron pairs in vivo, here we show that in fact, the zebrafish spinal cord contains two parallel, distinct microcircuits for independent control of dorsal and ventral musculature on each side of its body. During normal upright swimming, the dorsal and ventral microcircuits are equally active; but during postural correction, fish differentially engage these microcircuits to generate torque for self-righting. These findings reveal greater complexity in the fish spinal networks responsible for swimming than previously recognized. We suggest that these parallel microcircuits in early vertebrates represent a plausible template for the evolution of limb control in tetrapods.