Neuronal networks assemble the cellular elements required for specific behaviours. To understand a network , and thus the behaviour it influences, we need information on the properties of its component neurons and synaptic connections. My work examines neuronal network function using the spinal cord locomotor network of the lamprey, a lower vertebrate model system for investigating network function. We examine locomotor behaviour in intact animals, network activity in the isolated spinal cord, and the properties of network cells and synapses using electrophysiological and anatomical approaches. We also use computational models to address aspects of network. We are currently examining changes in network properties after spinal cord injury. The lamprey recovers locomotion function after complete spinal cord lesions. While this has been attributed to the regeneration of axons across lesion sites, regeneration alone cannot account for recovery. We have thus examined physiological and anatomical properties above below lesion sites, and have found marked changes in both sensory and motor systems. However, we currently do not know how these effects influence recovery. Our current analyses offer a number of potential projects in the intact and lesioned spinal cord: the use of mathematical and computational models to examine how identified network cellular and synaptic properties influence network function; experimental analyses of functional changes in networks above lesion sites; the time of onset (and potential decay) of changes above and below lesion sites; and how intrinsic injury-induced plasticity and endogenous neuromodulatory effects interact to influence recovery
- Cooke R, Parker D (2009) Locomotor recovery after spinal cord lesions in the lamprey is associated with functional and ultrastructural changes below lesion sites. J Neurotrauma 26:597-612.
- Hoffman N, Parker D (2011) Interactive and individual effects of sensory potentiation and region-specific changes in excitability after spinal cord injury. Neuroscience 199:563-576.
- Parker D (2006) Complexities and uncertainties of neuronal network function. Philosophical Transactions of the Royal Society B: Biological Sciences 361:81-99.