Patch clamp recording from the intact dorsal root ganglion.
A method for patch-clamp recording from intact dorsal root ganglion (DRG) cells in rat is described. The L4 and L5 DRGs with sciatic nerve attached were excised from rats (10-15 days old) and placed in a recording chamber after removing the ganglion sheath and dissolving the connective tissue with dilute collagenase. The somata of individual cells were exposed by gentle surface cleaning through a perfusion micropipette. Somata were classified as Abeta, Adelta or C based on the cell size and the shape of the action potential (AP). Under current clamp, axonal conduction velocity (CV) was calculated from the distance between a stimulating electrode and the center of the ganglion divided by the latency of the AP elicited by stimulation of the sciatic nerve. CVs ranged from 0.2-0.8 m/s for C cells, 0.8-2.4 for Adelta and 3.2-5.0 for A/beta cells. AP threshold occurred at a significantly more positive potential in C cells than in Adelta and Abeta cells. Under voltage clamp, sodium currents were recorded from C cells. Both TTX-resistant (TTX-R) and TTX-sensitive (TTX-S currents) were demonstrated in the present study. The results demonstrate the feasibility of patch-clamp recording from intact, identified DRG cells in vitro.
Zhang
J M
JM
Department of Anesthesiology, Yale University School of Medicine, New Haven, CT 06520, USA. jmzhang@pantheon.yale.edu
Donnelly
D F
DF
LaMotte
R H
RH
D000818:Animals; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009431:Neural Conduction / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D013779:Tetrodotoxin / Q000494:pharmacology
D013779:Tetrodotoxin