Intracellular electrophysiological recordings were made in vitro at 36.5 degrees C from lumbar (L4 to L6) dorsal root ganglion neurones of 6-8-week-old female @entity35 . Electrophysiological properties were recorded prior to intracellular injection with fluorescent dye. The following showed substance P-like immunoreactivity (SP-LI): 8/19 C-fibre cells, 6/26 Adelta cells, and 0/52 Aalpha/beta cells. In C-fibre neurones, there were no significant differences in action potential (AP) characteristics between those with SP-LI and those without. In contrast, the Adelta neurones with SP-LI had significantly deeper and longer afterhyperpolarisations (AHPs), but their AP durations did not differ from those without SP-LI. Both SP-LI and calcitonin gene-related peptide-LI ( @entity4655 -LI) were examined on 18 Adelta and 11 C cells. Most (7/8) neurones with SP-LI also showed @entity4655 -LI, but only 7/21 neurones without SP-LI showed @entity4655 -LI. One C cell showed SP-LI but no @entity4655 -LI. Neurones with neither peptide (-/-), with only @entity4655 (-/ @entity4655 ) or with both peptides (SP/ @entity4655 ) were compared (n = 28). The numbers in each group were, respectively, 5, 2, and 3 with C-fibres and 9, 5, and 4 with Adelta-fibres. The peptide content and AP shape were related in Adelta neurones. Most -/- Adelta neurones had short APs and short AHPs; most -/ @entity4655 neurones had long APs and long AHPs, and SP/ @entity4655 neurones had short APs with deep, long AHPs. There was a positive correlation between log10 of the area under the AP (AP area) and log10 AHP duration in Adelta neurones. All SP- and most @entity4655 -containing Adelta neurones had AP shapes similar to those previously described for nociceptive neurones. However, a few without peptide also showed such properties, raising the possibility that some nociceptive neurones did not express these peptides.

Differing action potential shapes in XXXX dorsal root ganglion neurones related to their substance P and calcitonin gene-related peptide immunoreactivity.

@entity35 :: ('10116', 'Species') :: ['rats'] @entity4655 :: ('24241(Tax:10116)', 'Gene') :: ['CGRP']
@entity35 :: (10116,Species) :: ['rat']
