Peripheral Glutamate Receptors Are Required for Hyperalgesia Induced by Capsaicin

Table 1

Mean value of c-Fos-ir cells in the dorsal horn of L4-L5 2 h after s.c. injection of capsaicin, glutamate, and glutamate receptors antagonists with/without capsaicin. The value in each group was represented mean ± SEM obtained from at least 10 animals, and the difference of the means was analyzed with the Student’s t-test.

Group	Ipsilateral		Contralateral
	I/II-layer	III⧵IV-layer	I/II-layer	III⧵IV-layer
Vehicle	60 ± 5	22 ± 8	12 ± 4	7 ± 2
Capsaicin(cap)	489 ± 34*	63 ± 18	44 ±13	20±9
Glutamate	283 ± 18*	36 ± 5	19 ± 8	12±6
MK801	79 ± 3	11 ± 7	33 ± 12	9 ± 5
CNQX	70 ± 8	7 ± 3	14 ± 7	3 ± 2
CPCCOEt	59 ± 8	6 ± 3	10 ± 4	6 ± 2
MCCG	63 ± 10	5 ± 2	28 ± 11	5 ± 2
MSOP	66 ± 16	5 ± 3	9 ± 4	5 ± 3
Cap + MK801	227 ± 32^#	14 ± 4	8 ± 6	3 ±2
Cap + CNQX	205 ± 40^#	11 ± 7	22 ± 12	3 ± 2
Cap + CPCCOEt	236 ± 58^#	17 ± 11	12 ± 7	4 ± 3
Cap + MCCG	560 ± 85	27 ± 10	24 ± 9	3 ± 1
Cap + MSOP	383 ± 21	22 ± 3	18 ± 13	4 ± 1

*Significant difference at 𝑃<0.05 between vehicle and capsaicin, or glutamate-treated group. ^#Significant difference at P < 0.05 between capsaicin and capsaicin + MK801, or capsaicin + CNQX, or capsaicin + CPCCOEt-treated group.