Gaussian white noise stimulation as an alternative method to excite sensory neurons.

Introduction: Peripheral nerve endings of dorsal root ganglion (DRG) neurons act as nociceptors and generate action potentials in response to noxious stimuli. Primary cultures of dissociated DRG have been used extensively to study changes neuronal excitability caused by either analgesics or pathological conditions, such as inflammation. The dissociation procedure can be viewed as a form of axotomy, and one might expect a resulting increase in excitability of the neurons during the subsequent culture period. However, changes in firing properties of DRG neurons over time Methods: Thus, the current experiments compared action potential firing in dissociated DRG neurons after one to 7 days in culture and examined Gaussian white noise as novel stimulation paradigm. Primary cultures of DRG neurons were recorded in perforated patch current-clamp. Action potentials were evoked either by a sequence of five rectangular current pulses with increasing amplitudes or by Gaussian white noise of varying RMS amplitudes and frequencies. Results: Conventional rectangular current injections triggered 19 Discussion: These results demonstrate a decrease in the excitability of DRG neurons from day one to 7 after dissociation and reveal Gaussian white noise as reliable trigger of action potential firing in these neurons.