A pruritogen 5-HT-induced itching on synaptic transmission in spinal superficial dorsal horn neurons -In vivo patch-clamp recording analyse-

The lower thresholds and increased excitability of dorsal horn neurons in the neonatal rat suggest that inhibitory processing is less efficient in the immature spinal cord. This is unlikely to be explained by an absence of functional GABAergic inhibition because antagonism of γ-aminobutyric acid (GABA) type A receptors augments neuronal firing in vivo from the first days of life. However, it is possible that more subtle deficits in GABAergic signaling exist in the neonate, such as decreased reliability of transmission or greater depression during repetitive stimulation, both of which could influence the relative excitability of the immature spinal cord. To address this issue we examined monosynaptic GABAergic inputs onto superficial dorsal horn neurons using whole cell patch-clamp recordings made in spinal cord slices at a range of postnatal ages (P3, P10, and P21). The amplitudes of evoked inhibitory postsynaptic currents (IPSCs) were significantly lower and showed greater variability in younger animals, suggesting a lower fidelity of GABAergic signaling at early postnatal ages. Paired-pulse ratios were similar throughout the postnatal period, whereas trains of stimuli (1, 5, 10, and 20 Hz) revealed frequency-dependent short-term depression (STD) of IPSCs at all ages. Although the magnitude of STD did not differ between ages, the recovery from depression was significantly slower at immature GABAergic synapses. These properties may affect the integration of synaptic inputs within developing superficial dorsal horn neurons and thus contribute to their larger receptive fields and enhanced afterdischarge.

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Changes in synaptic transmission of substantia gelatinosa neurons in a rat model of lumbar radicular pain revealed by in vivo patch-clamp recording

Pain ◽

10.1016/j.pain.2010.12.039 ◽

2011 ◽

Vol 152 (5) ◽

pp. 1024-1032 ◽

Cited By ~ 13

Author(s):

Yoshinori Terashima ◽

Mikito Kawamata ◽

Tsuneo Takebayashi ◽

Satoshi Tanaka ◽

Katsumasa Tanimoto ◽

...

Keyword(s):

Patch Clamp ◽

Synaptic Transmission ◽

Rat Model ◽

Radicular Pain ◽

Substantia Gelatinosa ◽

Patch Clamp Recording ◽

Lumbar Radicular Pain

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Changes in synaptic transmission of substantia gelatinosa neurons after spinal cord hemisection revealed by analysis using in vivo patch-clamp recording

Molecular Pain ◽

10.1177/1744806916665827 ◽

2016 ◽

Vol 12 ◽

pp. 174480691666582 ◽

Cited By ~ 3

Author(s):

Yuji Kozuka ◽

Mikito Kawamata ◽

Hidemasa Furue ◽

Takashi Ishida ◽

Satoshi Tanaka ◽

...

Keyword(s):

Spinal Cord ◽

Patch Clamp ◽

Synaptic Transmission ◽

Substantia Gelatinosa ◽

Patch Clamp Recording ◽

Spinal Cord Hemisection

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In vivo patch-clamp recording analysis of serotonin-induced itching on synaptic transmission in substantia gelatinosa neurons

Neuroscience Research ◽

10.1016/j.neures.2011.07.1581 ◽

2011 ◽

Vol 71 ◽

pp. e360-e361

Author(s):

Daisuke Uta ◽

Yoshikazu Gotoh ◽

Tsugunobu Andoh ◽

Yasushi Kuraishi ◽

Keiji Imoto ◽

...

Keyword(s):

Patch Clamp ◽

Synaptic Transmission ◽

Substantia Gelatinosa ◽

Patch Clamp Recording ◽

Recording Analysis

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ATP P2× Receptors and Sensory Synaptic Transmission Between Primary Afferent Fibers and Spinal Dorsal Horn Neurons in Rats

Journal of Neurophysiology ◽

10.1152/jn.1998.80.6.3356 ◽

1998 ◽

Vol 80 (6) ◽

pp. 3356-3360 ◽

Cited By ~ 90

Author(s):

Ping Li ◽

Amelita A. Calejesan ◽

Min Zhuo

Keyword(s):

Spinal Cord ◽

Synaptic Transmission ◽

Dorsal Horn ◽

Lumbar Spinal Cord ◽

Superficial Dorsal Horn ◽

Primary Afferent ◽

Dorsal Horn Neurons ◽

Afferent Fibers ◽

Primary Afferent Fibers ◽

Lumbar Spinal

Li, Ping, Amelita A. Calean, and Min Zhuo. ATP P2× receptors and sensory synaptic transmission between primary afferent fibers and spinal dorsal horn neurons in rats. J. Neurophysiol. 80: 3356–3360, 1998. Glutamate is a major fast transmitter between primary afferent fibers and dorsal horn neurons in the spinal cord. Recent evidence indicates that ATP acts as another fast transmitter at the rat cervical spinal cord and is proposed to serve as a transmitter for nociception and pain. Sensory synaptic transmission between dorsal root afferent fibers and neurons in the superficial dorsal horn of the lumbar spinal cord were examined by whole cell patch-clamp recording techniques. Experiments were designed to test if ATP could serve as a transmitter at the lumbar spinal cord. Monosynaptic excitatory postsynaptic currents (EPSCs) were completely abolished after the blockade of both glutamatergic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate and N-methyl-d-aspartate receptors. No residual current was detected, indicating that glutamate but not ATP is a fast transmitter at the dorsal horn of the lumbar spinal cord. Pyridoxal-phosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS), a selective P2× receptor antagonist, produced an inhibitory modulatory effect on fast EPSCs and altered responses to paired-pulse stimulation, suggesting the involvement of a presynaptic mechanism. Intrathecal administration of PPADS did not produce any antinociceptive effect in two different types of behavioral nociceptive tests. The present results suggest that ATP P2×2 receptors modulate excitatory synaptic transmission in the superficial dorsal horn of the lumbar spinal cord by a presynaptic mechanism, and such a mechanism does not play an important role in behavioral responses to noxious heating. The involvement of other P2× subtype receptors, which is are less sensitive to PPADS, in acute nociceptive modulation and persistent pain remains to be investigated.

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