Spinal cholinergic interneurones influencing sympathetic function: a wider role in integration? (360G-Wellcome-093072_Z_10_Z)

Cholinergic transmission is an important mechanism for control of neuronal circuitry throughout the CNS. At the spinal cord level, cholinergic interneurones are thought to play roles in motor, sensory and sympathetic processing, however information regarding those interneurones involved in sympathetic control is lacking. Based on our preliminary evidence indicating extensive axonal arborisation from these neurones, we propose a novel hypothesis for a role of cholinergic interneurones in the in tegration of sympathetic, motor and sensory activity from the spinal cord. We will identify interneurones using cholinergic reporter mice and use electrophysiological, anatomical and immunohistochemical means to fully characterise these interneurones. We will determine their electrophysiological properties, axonal projections and synaptic inputs that influence their activity in spinal cord slices. We will determine any subclassification of these neurones based on these properties. We will inv estigate, both functionally and morphologically, how descending and afferent pathways influence their activity. The full axonal arborisation patterns of these cholinergic interneurones may give an insight into possible co-ordination of sympathetic and other motor outflows. This study will provide the first characterization of spinal cholinergic interneurones that may co-ordinate spinal activity and will provide insight into their targets and innervation patterns throughout the spinal cord.