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Neuroscience

Preparation of Acute Spinal Cord Slices for Whole-cell Patch-clamp Recording in Substantia Gelatinosa Neurons

Published: January 18th, 2019

DOI:

10.3791/58479

1Department of Pain, First Affiliated Hospital of Nanchang University, 2Department of Pediatrics, First Affiliated Hospital of Nanchang University, 3Center for Laboratory Medicine, First Affiliated Hospital of Nanchang University

Here, we describe the essential steps for whole-cell patch-clamp recordings made from substantia gelatinosa (SG) neurons in the in vitro spinal cord slice. This method allows the intrinsic membrane properties, synaptic transmission and morphological characterization of SG neurons to be studied.

Recent whole-cell patch-clamp studies from substantia gelatinosa (SG) neurons have provided a large body of information about the spinal mechanisms underlying sensory transmission, nociceptive regulation, and chronic pain or itch development. Implementations of electrophysiological recordings together with morphological studies based on the utility of acute spinal cord slices have further improved our understanding of neuronal properties and the composition of local circuitry in SG. Here, we present a detailed and practical guide for the preparation of spinal cord slices and show representative whole-cell recording and morphological results. This protocol permits ideal neuronal preservation and can mimic in vivo conditions to a certain extent. In summary, the ability to obtain an in vitro preparation of spinal cord slices enables stable current- and voltage-clamp recordings and could thus facilitate detailed investigations into the intrinsic membrane properties, local circuitry and neuronal structure using diverse experimental approaches.

The substantia gelatinosa (SG, lamina II of the spinal dorsal horn) is an indisputably important relay center for transmitting and regulating sensory information. It is composed of excitatory and inhibitory interneurons, which receive inputs from the primary afferent fibers, local interneurons, and the endogenous descending inhibitory system1. In recent decades, the development of acute spinal cord slice preparation and the advent of whole-cell patch-clamp recording have enabled various studies on the intrinsic electrophysiological and morphological properties of SG neurons2,3,

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All experimental protocols described were approved by the Animal Ethics Committee of Nanchang University (Nanchang, PR China, Ethical No.2017-010). All efforts were made to minimize the stress and pain of the experimental animals. The electrophysiological recordings performed here were carried out at room temperature (RT, 22–25 °C).

1. Animals

  1. Use Sprague-Dawley rats (3–5 weeks old) of either sex. House the animals under a 12 h light-dark cycle and give them ad.......

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Acute spinal cord slices were prepared according to the diagram shown in Figure 1. After slicing and recovery, a spinal cord slice was transferred to the recording chamber. Healthy neurons were identified based on soma appearance using IR-DIC microscopy. Next, the action potentials of SG neurons were elicited by a series of depolarizing current pulses (1 s duration) when neurons were held at RMP. As shown in Figure 2, the firing .......

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This protocol details the steps for preparing spinal cord slices, which we have used successfully when performing whole-cell patch-clamp experiments on SG neurons18,19,20,21. By implementing this method, we recently reported that minocycline, a second generation of tetracycline, could markedly enhance inhibitory synaptic transmission through a presynaptic mechanism in SG neurons

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This work was supported by grants from the National Natural Science Foundation of China (No. 81560198, 31660289).

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Name Company Catalog Number Comments
NaCl Sigma S7653 Used for the preparation of ACSF and PBS
KCl Sigma 60130 Used for the preparation of ACSF, sucrose-ACSF, and K+-based intracellular solution
NaH2PO4·2H2O Sigma 71500 Used for the preparation of ACSF, sucrose-ACSF and PBS
CaCl2·2H2O Sigma C5080 Used for the preparation of ACSF and sucrose-ACSF
MgCl2·6H2O Sigma M2670 Used for the preparation of ACSF and sucrose-ACSF
NaHCO3 Sigma S5761 Used for the preparation of ACSF and sucrose-ACSF
D-Glucose Sigma G7021 Used for the preparation of ACSF
Ascorbic acid Sigma P5280 Used for the preparation of ACSF and sucrose-ACSF
Sodium pyruvate Sigma A7631 Used for the preparation of ACSF and sucrose-ACSF
Sucrose Sigma S7903 Used for the preparation of sucrose-ACSF
K-gluconate Wako 169-11835 Used for the preparation of K+-based intracellular solution
Na2-Phosphocreatine Sigma P1937 Used for the preparation of intracellular solution
EGTA Sigma E3889 Used for the preparation of intracellular solution
HEPES Sigma H4034 Used for the preparation of intracellular solution
Mg-ATP Sigma A9187 Used for the preparation of intracellular solution
Li-GTP Sigma G5884 Used for the preparation of intracellular solution
CsMeSO4 Sigma C1426 Used for the preparation of Cs+-based intracellular solution
CsCl Sigma C3011 Used for the preparation of Cs+-based intracellular solution
TEA-Cl Sigma T2265 Used for the preparation of Cs+-based intracellular solution
Neurobiotin 488 Vector SP-1145 0.05% neurobiotin 488 could be used for morphological studies
Agar Sigma A7002 3% agar block was used in our protocol
Paraformaldehyde Sigma P6148 4% paraformaldehyde was used for immunohistochemical processing
Na2HPO4 Hengxing Chemical Reagents Used for the preparation of PBS
Mount Coverslipping Medium Polyscience 18606
Urethan National Institute for Food and Drug Control 30191228 1.5 g/kg, i.p.
Borosilicate glass capillaries World Precision Instruments TW150F-4 1.5 mm OD, 1.12 mm ID
Micropipette puller Sutter Instrument P-97 Used for the preparation of micropipettes
Vibratome Leica VT1000S
Vibration isolation table Technical Manufacturing Corporation 63544
Infrared CCD camera Dage-MIT IR-1000
Patch-clamp amplifier HEKA EPC-10
Micromanipulator Sutter Instrument MP-285
X-Y stage Burleigh GIBRALTAR X-Y
Upright microscope Olympus BX51WI
Osmometer Advanced FISKE 210
PH meter Mettler Toledo FE20
Confocol microscope Zeiss LSM 700

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