Table 1.

Summary of Dorsal Root Ganglia (DRG) cell characteristics and pharmacological responses used for cell classification. DRG were excised from transgenic mice expressing green fluorescent protein (GFP) coupled with the calcitonin gene-related protein (CGRP) to identify peptidergic neurons. Primary culture DRG cells were labeled using fluorescently labeled isolectin B4 (IB4), a glycan-specific lectin used to identify non-peptidergic nociceptors, a specific neuronal subclass. The presence/absence of VGCC in the satellite glial cells, the main glial cell class in the DRG, is rather controversial: although calcium currents (I_Ca) have been detected in non-neuronal cells from the DRG using whole-cell patch clamp [29], they have not been directly detected by other methods, and it is generally accepted that they lack VGCC [30,31]. The table includes pertinent (but not all) ion channels and receptors found in DRG cells. Legend for table symbols: glia, gray star; large diameter neurons L1-L4, gray circle with lines; large diameter neurons L5-L6, green circle; peptidergic nociceptor medium diameter neurons, green square; non-petidergic nociceptor medium diameter neurons, orange square with lines; small diameter neurons, gray triangle with lines.

Cell Class		Cell Subclass	Voltage Gated Channels				TRP Channels			GFP +	IB4 +
			Ca	Na	K	Cl	V1	A1	M8
Glia		-	+/−	−	+	+	−	−	−	−	−
Large diameter neurons		L1–L4	+	+	+	+	−	−	−	−	−
		L5–L6	+	+	+	+	−	−	−	+	−
Medium diameter neurons		Peptidergic nociceptors	+	+	+	+	+	+	+	+	−
		Non-peptidergic nociceptors	+	+	+	+	+	+	−	−	+
Small diameter neurons		-	+	+	+	+	+	+	+	−	−