Hulsey D, Hays S, Khodaparast, N, Casavant R, Ruiz A, Das P, Nutting E, Carrier X, Iyengar M, Quareshi I, Sultana S, Rennaker R, Kilgard M (2014) Vagus nerve stimulation dependent enhancement of cortical plasticity requires cholinergic innervation of the cortex. Neuroscience 2014 Abstracts 542.20. Society for Neuroscience, Washington, DC.
Summary: Primary motor cortex (M1) transiently reorganizes in response to motor skill learning. Pairing forelimb movements with Vagus Nerve Stimulation (VNS) drives enhanced and robust analogous plasticity within M1. These changes occur outside of the typical period for motor plasticity and are independent of new skill learning. The mechanism by which VNS enhances M1 plasticity is not well understood. Skill learning and the associated cortical plasticity is dependent on cholinergic innervation of the cortex. VNS may enhance plasticity by engaging neuromodulatory systems necessary for plasticity. We hypothesize that cholinergic innervation of M1 is necessary for motor plasticity associated with VNS pairing. To test this hypothesis, we trained female Sprague Dawley rats on a skilled lever pressing task emphasizing use of the proximal forelimb. After task acquisition, one group of rats received a lesion to the cholinergic neurons of the basal forebrain using 192-IgG-Saporin, while another group received a control injection. All subjects also received a VNS cuff implant during the surgery. After one week of recovery, all subjects receive VNS paired to successful task performances for five days. Intracortical microstimulation was performed to derive M1 maps of each group 24 hours after their final VNS paired session. Subjects with an intact cholinergic system show significant expansion of proximal forelimb representation over naïve animals within the cortex. Subjects without cholinergic innervation of the cortex show no difference in M1 organization when compared to naïve animals. We conclude that cholinergic innervation is necessary for the effects of VNS on motor plasticity.
Related Products: 192-IgG-SAP (Cat. #IT-01)