Electrophysiological characteristics of identified kidney-related neurons in adult rat spinal cord slices.

Neurosci Lett. 2010 May 3;474(3):168-72. doi: 10.1016/j.neulet.2010.03.036. Epub 2010 Mar 18. Derbenev AV, Duale H, Rabchevsky AG, Smith BN. In this paper, they wanted to characterize the preganglionic kidney-related cells in the IML, so they applied a transynaptic pseudorabies virus within the kidney to label them. 84 hours later the animals were perfused with ice cold ringer, and slices of the spinal cord were made and used for whole cell patch clamp on labeled cells. Co-stains were performed for their PRV eGFP marker as well as ChAT (as well as the biocytin that was present in their recording electrode), showing that these kidney-related cells were mostly cholinergic, with 3 or more primary dendrites, and which area of the IML they were most likely to be in (lateral edge of they gray matter). During recording of GFP labeled cells, they were able to see that there were frequent GABA-A related small inhibitory postsynaptic currents and glutamate-mediated small excitatory postsynaptic currents. Since they saw increased glutamate signaling, they propose that the cells are under tonic glutamatergic activation. I'm not sure that severed in vitro presynaptic axons are entirely representative of an intact in vivo physiological system, but I'm still kind of new to this and there's probably a lot of work that's been done that could teach me a thing or two. -DH