pain의 분자생물학 수준의 이해

[문형철]

기쁘다.

이 깊이까지 통증을 공부할 수 있는 기회를 갖게 되어 기쁘다.

panic bird.

개념. projection과 intrinsic neuron

(A) Projection neurons; (B) intrinsic neurons. The projection neurons of the cortex are pyramidal cells, and the intrinsic cells are simply called interneurons. The projection neuron of the cerebellum is the Purkinje cell, and the intrinsic cells are the granule, basket, stellate and Golgi cells.The projection neurons of the retina are the retinal ganglion cells, and the intrinsic cells are a diverse collection of bipolar and amacrine cells. Note that two-dimensional representations of the cells, as shown here, are sometimes realistic and sometimes not. Because the cell is essentially flat, a Purkinje cell can be correctly shown in two dimensions; such an image of many other neurons is nearly unintelligible, because a three-dimensional structure is projected onto two dimensions.For that reason, the drawings are simplified, with the goal of conveying the most important features. Cajal's drawings are works of art, not literal images of cells as seen from any physically possible angle.

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Differential inhibitory signalling in the superficial and deep dorsal horn of the mouse spinal cord
W.B. Anderson,1,2 B.A. Graham,1,2 P. Jobling,1,2 P.A. Tooney,1,2 A.M. Brichta1,2 and R.J. Callister,1,2 1School of
Biomedical Sciences, University of Newcastle, Callaghan, NSW 2308, Australia and 2Hunter Medical Research
Institute (HMRI), Lookout Road, New Lambton, NSW 2310, Australia.

Neurons in the superficial (SDH; laminae I-II) and deep (DDH; laminae IV-VI) dorsal horn of the spinal
cord receive synaptic inputs from the periphery via small and medium diameter afferent fibres, respectively.
Both regions have well-established, although largely separate, roles in the spinal processing of pain signals.
Despite this, fast synaptic inhibition is provided by glycine- and GABAA- receptors in both regions under
normal conditions and both receptor types been implicated in the onset and maintenance of pathological pain
states. Until recently, glycine receptors (GlyRs) throughout the adult nervous system were thought to be
composed of a1/b-subunits, however an unusual form of the GlyR, containing a3-subunits, has recently been
identified in the SDH, but not the DDH (Harvey et al., 2004). Moreover, tonic inhibitory drive mediated by
glycine and GABAA receptors differs in the superficial and deep layers of the dorsal horn (Cronin et al., 2004).
To further understand the contribution of these two inhibitory transmitter systems in spinal pain processing, we
compared the electrophysiological properties of synaptically located GlyRs and GABAARs in the SDH and
DDH. Mice (C57Bl/6, both sexes, P17-37) were anaesthetised (Ketamine, 100 mg/kg, i.p.) and decapitated.
Transverse slices (300 um thick) were prepared from the spinal cord (L3-L5 segments) and voltage-clamp
recordings were made from SDH and DDH neurons (CsCl internal; holding potential 70 mV; 23oC).
Strychnine-sensitive (1 um) glycinergic mIPSCs were recorded in the presence of tetrodotoxin (1 μM), CNQX
(10 μM) and bicuculline (10 μM). Bicuculline-sensitive (10 μM) GABAAergic mIPSCs were recorded in the
presence of tetrodotoxin (1 μM), CNQX (10 μM) and strychnine (1 μM). Glycinergic mIPSCs were detected in
23/35 SDH neurons, but were observed in all DDH neuron recordings (20/20). In contrast, GABAAergic
mIPSCs were present on all (n = 15) neurons tested in the SDH, but on only 15/18 neurons in the DDH. Several
properties of the two receptors also differed in the SDH and DDH. For example, glycinergic mIPSC amplitude
was smaller (38.0 ± 3.2 vs. 55.5 ± 5.6 pA; p < 0.05), mIPSC decay time was slower (10.3 ± 0.5 vs. 5.1 ± 0.4 ms;
p < 0.05), and mIPSC frequency was lower (0.24 ± 0.04 vs. 0.90 ± 0.17 Hz; p < 0.05) in SDH vs DDH neurones.
In contrast, GABAAergic mIPSCs had similar amplitudes (15.6 ± 1.3 vs. 16.2 ± 2.2 pA) and frequencies (0.16 ±
0.06 vs. 0.18 ± 0.06 Hz); however, decay times were also slower (23.0 ± 2.4 vs. 12.3 ± 0.8 ms) in SDH vs DDH
neurones. Interestingly, the mean single channel current underlying these mIPSCs, estimated using peak-scaled
non-stationary noise analysis, was identical in both regions for GlyR (3.9 ± 0.7 pA, n = 11 vs. 3.8 ± 0.7, n = 8)
and GABAAR (1.6 ± 0.1 pA, n = 10 vs. 1.6 ± 0.2 pA, n = 11). These electrophysiological data were compared
with results from real-time PCR analysis of the expression‎ of GlyR subunits (a1-4 and b) in the SDH and DDH.
The a1 subunit gene was highly expressed in both SDH and DDH, although levels were increased three-fold in
the SDH. The b subunit was also highly expressed throughout the dorsal horn, however levels were three-fold
higher in the DDH. The expression‎ of a3 subunit was lower, relative to a1 and b subunits, but at three fold
higher levels in the SDH vs. DDH. Together, these data indicate that glycine and GABAA receptors with
differing physiological properties contribute to fast synaptic inhibition in deep and superficial regions of the
mouse dorsal horn. These features are likely to influence pain processing differently in the SDH and DDH and
provide a basis for selectively modifying inhibition in the two regions.
Cronin JN,

deep dorsal horn과 관련된 논문

Dorsal Horn Neurons Contributes to Inflammatory Pain hypers.pdf

Modulatory Actions of Serotonin, Norepinephrine, Dopamine, .pdf

신경병증 통증모델의 백서에서 R-PIA의 기계.pdf

Models and Mechanisms of Hyperalgesia and Allodynia.pdf

Peripheral nerve injury sensitizes neonatal dorsal horn neu.pdf

superficial dorsal horn과 관련된 논문

Activation of Superficial Dorsal Horn Neurons in the Mouse .pdf

Responses of Superficial Dorsal Horn Neurons to Intradermal.pdf

[PT 균]

어렵네요^ ^