Abstract
To study the functional projection patterns of the primary afferents in the spinal cord, the postsynaptic responses of substantia gelatinosa (SG) neurones evoked by L5 dorsal root stimulation (DRS) were examined from the neurones located at L2 to S1 in horizontal slices of the adult rat spinal cord using a blind whole-cell patch-clamp technique. In the voltage-clamp mode, the L5 DRS evoked the Aδ and C-afferent-mediated excitatory postsynaptic currents (EPSCs) in more than 70% of the neurones tested at the L5 level. Both Aδ- and C-afferent EPSCs were also recorded in more than 50% of the neurones at L4. At L3 and L6, the number of neurones receiving the C-afferent EPSCs (> 40%) was significantly greater than that of Aδ-afferent EPSCs (< 20%). On the other hand, the Aδ and C-afferent-mediated inhibitory postsynaptic currents (IPSCs) elicited by L5 DRS were almost equally observed from L2 to S1. In the current-clamp mode, L5 DRS evoked Aδ and C-afferent-mediated EPSPs, some of which initiated action potentials (APs). Most of the Aδ-afferent-mediated APs were limited at the L5 level, while C-afferent-mediated APs were observed at L5 and L4. As the L2 DRS-evoked APs in the L2 SG neurones were suppressed by L5 DRS, the widespread distribution of the inhibitory inputs was considered to be functional. These findings suggest that the excitatory projection of the C afferents to the SG neurones was thus spread more rostrocaudally than that of the Aδ afferents, thereby contributing to more diffuse pain transmission. In addition, the widespread distribution of the inhibitory inputs may thus play a role as a lateral inhibitory network and thereby prevent the expansion of the excitatory inputs of noxious stimuli.
| Original language | English |
|---|---|
| Pages (from-to) | 303-315 |
| Number of pages | 13 |
| Journal | Journal of Physiology |
| Volume | 560 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Oct 1 2004 |
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All Science Journal Classification (ASJC) codes
- Physiology
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Electrophysiological mapping of the nociceptive inputs to the substantia gelatinosa in rat horizontal spinal cord slices. / Kato, Go; Furue, Hidemasa; Katafuchi, Toshihiko; Yasaka, Toshiharu; Iwamoto, Yukihide.
In: Journal of Physiology, Vol. 560, No. 1, 01.10.2004, p. 303-315.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Electrophysiological mapping of the nociceptive inputs to the substantia gelatinosa in rat horizontal spinal cord slices
AU - Kato, Go
AU - Furue, Hidemasa
AU - Katafuchi, Toshihiko
AU - Yasaka, Toshiharu
AU - Iwamoto, Yukihide
PY - 2004/10/1
Y1 - 2004/10/1
N2 - To study the functional projection patterns of the primary afferents in the spinal cord, the postsynaptic responses of substantia gelatinosa (SG) neurones evoked by L5 dorsal root stimulation (DRS) were examined from the neurones located at L2 to S1 in horizontal slices of the adult rat spinal cord using a blind whole-cell patch-clamp technique. In the voltage-clamp mode, the L5 DRS evoked the Aδ and C-afferent-mediated excitatory postsynaptic currents (EPSCs) in more than 70% of the neurones tested at the L5 level. Both Aδ- and C-afferent EPSCs were also recorded in more than 50% of the neurones at L4. At L3 and L6, the number of neurones receiving the C-afferent EPSCs (> 40%) was significantly greater than that of Aδ-afferent EPSCs (< 20%). On the other hand, the Aδ and C-afferent-mediated inhibitory postsynaptic currents (IPSCs) elicited by L5 DRS were almost equally observed from L2 to S1. In the current-clamp mode, L5 DRS evoked Aδ and C-afferent-mediated EPSPs, some of which initiated action potentials (APs). Most of the Aδ-afferent-mediated APs were limited at the L5 level, while C-afferent-mediated APs were observed at L5 and L4. As the L2 DRS-evoked APs in the L2 SG neurones were suppressed by L5 DRS, the widespread distribution of the inhibitory inputs was considered to be functional. These findings suggest that the excitatory projection of the C afferents to the SG neurones was thus spread more rostrocaudally than that of the Aδ afferents, thereby contributing to more diffuse pain transmission. In addition, the widespread distribution of the inhibitory inputs may thus play a role as a lateral inhibitory network and thereby prevent the expansion of the excitatory inputs of noxious stimuli.
AB - To study the functional projection patterns of the primary afferents in the spinal cord, the postsynaptic responses of substantia gelatinosa (SG) neurones evoked by L5 dorsal root stimulation (DRS) were examined from the neurones located at L2 to S1 in horizontal slices of the adult rat spinal cord using a blind whole-cell patch-clamp technique. In the voltage-clamp mode, the L5 DRS evoked the Aδ and C-afferent-mediated excitatory postsynaptic currents (EPSCs) in more than 70% of the neurones tested at the L5 level. Both Aδ- and C-afferent EPSCs were also recorded in more than 50% of the neurones at L4. At L3 and L6, the number of neurones receiving the C-afferent EPSCs (> 40%) was significantly greater than that of Aδ-afferent EPSCs (< 20%). On the other hand, the Aδ and C-afferent-mediated inhibitory postsynaptic currents (IPSCs) elicited by L5 DRS were almost equally observed from L2 to S1. In the current-clamp mode, L5 DRS evoked Aδ and C-afferent-mediated EPSPs, some of which initiated action potentials (APs). Most of the Aδ-afferent-mediated APs were limited at the L5 level, while C-afferent-mediated APs were observed at L5 and L4. As the L2 DRS-evoked APs in the L2 SG neurones were suppressed by L5 DRS, the widespread distribution of the inhibitory inputs was considered to be functional. These findings suggest that the excitatory projection of the C afferents to the SG neurones was thus spread more rostrocaudally than that of the Aδ afferents, thereby contributing to more diffuse pain transmission. In addition, the widespread distribution of the inhibitory inputs may thus play a role as a lateral inhibitory network and thereby prevent the expansion of the excitatory inputs of noxious stimuli.
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UR - http://www.scopus.com/inward/citedby.url?scp=6444236827&partnerID=8YFLogxK
U2 - 10.1113/jphysiol.2004.068700
DO - 10.1113/jphysiol.2004.068700
M3 - Article
C2 - 15297573
AN - SCOPUS:6444236827
VL - 560
SP - 303
EP - 315
JO - Journal of Physiology
JF - Journal of Physiology
SN - 0022-3751
IS - 1
ER -