Non-synaptic Modulation of Motor Neuron Activity, Shine Chin, Neuroscience Graduate Student, University of Arizona

Abstract: Conventional thinking is that the spiking rate output of a typical mammalian neuron is roughly proportional to the net excitatory synaptic input received. However, the discovery of intrinsically (i.e. non-synaptic) induced membrane depolarization challenges that view. One such mechanism is the activation of L-type calcium channels in motor neurons that drive persistent inward currents (PICs) strong enough to cause spiking in the absence of extrinsic excitatory input. Unfortunately, there is minimal information on the role PICs play during natural behavior. To address this gap, we are using targeted pharmacology to the block ion channels thought to underlie the production of PICs while recording motor neuron activity in awake rats performing learned motor behaviors. Results from this experiment can, for the first time, provide insight into how PICs affect neuron spiking behavior in awake, behaving animals.