Name: in vitro characterization of the electrophysiological properties of colonic afferent fibers in rats
Uploaded: 2017-09-27T14:00:00
Description: Watch this Scientific Journal Video about In Vitro Characterization of the Electrophysiological Properties of Colonic Afferent Fibers in Rats at JoVE.com

This protocol was supported by research grants from the National Natural Science Foundation of China (#31171066, #81270464) and the Sino-German Science Center (GZ919).

The experimental protocol reported here has been approved by the Animal Ethical Committee of Shanghai Jiaotong University School of Medicine (# SYXK2013-0050).&#160;The dissection of the colorectum with intact ganglion and nerve trunk takes a minimum of 15 minutes for a person quite experienced in this technique. It is therefore necessary to keep the animal alive but under deep anesthesia whilst performing the dissections, to ensure viability of the tissue for subsequent electrophysiological recording.
<p class="jove...

<ol>
	<li>Al-Chaer, E. D., Traub, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+basis+of+visceral+pain:+recent+developments.">Biological basis of visceral pain: recent developments.</a> Pain. 96 (3), 221-225 (2002).</li><li>Christianson, J. A., Traub, R. J., Davis, B. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differences+in+spinal+distribution+and+neurochemical+phenotype+of+colonic+afferents+in+mouse+and+rat.">Differences in spinal distribution and neurochemical phenotype of colonic afferents in mouse and rat.</a> J Comp Neurol. 494 (2), 246-259 (2006).</li><li>Wynn, G., Rong, W., Xiang, Z., Burnstock, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purinergic+mechanisms+contribute+to+mechanosensory+transduction+in+the+rat+colorectum.">Purinergic mechanisms contribute to mechanosensory transduction in the rat colorectum.</a> Gastroenterology. 125 (5), 1398-1409 (2003).</li><li>Dong, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impairments+of+the+Primary+Afferent+Nerves+in+a+Rat+Model+of+Diabetic+Visceral+Hyposensitivity.">Impairments of the Primary Afferent Nerves in a Rat Model of Diabetic Visceral Hyposensitivity.</a> Mol Pain. 11, (2016).</li><li>Lynn, P. A., Blackshaw, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+recordings+of+afferent+fibres+with+receptive+fields+in+the+serosa,+muscle+and+mucosa+of+rat+colon.">In vitro recordings of afferent fibres with receptive fields in the serosa, muscle and mucosa of rat colon.</a> J Physiol. 518 (Pt 1), 271-282 (1999).</li><li>Page, A. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Different+contributions+of+ASIC+channels+1a,+2,+and+3+in+gastrointestinal+mechanosensory+function.">Different contributions of ASIC channels 1a, 2, and 3 in gastrointestinal mechanosensory function.</a> Gut. 54 (10), 1408-1415 (2005).</li><li>Hockley, J. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=P2Y+Receptors+Sensitize+Mouse+and+Human+Colonic+Nociceptors.">P2Y Receptors Sensitize Mouse and Human Colonic Nociceptors.</a> J Neurosci. 36 (8), 2364-2376 (2016).</li><li>Peiris, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+visceral+afferent+recordings:+preliminary+report.">Human visceral afferent recordings: preliminary report.</a> Gut. 60 (2), 204-208 (2011).</li><li>Feng, B., Gebhart, G. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+silent+afferents+in+the+pelvic+and+splanchnic+innervations+of+the+mouse+colorectum.">Characterization of silent afferents in the pelvic and splanchnic innervations of the mouse colorectum.</a> Am J Physiol Gastrointest Liver Physiol. 300 (1), G170-G180 (2011).</li><li>Feng, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Activation+of+guanylate+cyclase-C+attenuates+stretch+responses+and+sensitization+of+mouse+colorectal+afferents.">Activation of guanylate cyclase-C attenuates stretch responses and sensitization of mouse colorectal afferents.</a> J Neurosci. 33 (23), 9831-9839 (2013).</li><li>Feng, B., Gebhart, G. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+Functional+Characterization+of+Mouse+Colorectal+Afferent+Endings.">In vitro Functional Characterization of Mouse Colorectal Afferent Endings.</a> J Vis Exp. (95), e52310 (2015).</li><li>Nullens, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+Vitro+Recording+of+Mesenteric+Afferent+Nerve+Activity+in+Mouse+Jejunal+and+Colonic+Segments.">In Vitro Recording of Mesenteric Afferent Nerve Activity in Mouse Jejunal and Colonic Segments.</a> J Vis Exp. (116), (2016).</li><li>Rong, W., Hillsley, K., Davis, J. B., Hicks, G., Winchester, W. J., Grundy, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Jejunalafferent+nerve+sensitivity+in+wild-type+and+TRPV1+knockout+mice.">Jejunalafferent nerve sensitivity in wild-type and TRPV1 knockout mice.</a> J Physiol. 560 (Pt 3), 867-881 (2004).</li><li>Brierley, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+chemosensory+function+and+receptor+expression+of+splanchnic+and+pelvic+colonic+afferents+in+mice).">Differential chemosensory function and receptor expression of splanchnic and pelvic colonic afferents in mice).</a> J Physiol. 567 (Pt 1), 267-281 (2005).</li><li>Brierley, S. M., Jones, R. C. 3. r. d., Gebhart, G. F., Blackshaw, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Splanchnic+and+pelvic+mechanosensory+afferents+signal+different+qualities+of+colonic+stimuli+in+mice.">Splanchnic and pelvic mechanosensory afferents signal different qualities of colonic stimuli in mice.</a> Gastroenterology. 127 (1), 166-178 (2004).</li><li>La, J. H., Schwartz, E. S., Gebhart, G. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differences+in+the+expression+of+transient+receptor+potential+channel+V1,+transient+receptor+potential+channel+A1+and+mechanosensitive+two+pore-domain+K++channels+between+the+lumbar+splanchnic+and+pelvic+nerve+innervations+of+mouse+urinary+bladder+and+colon.">Differences in the expression of transient receptor potential channel V1, transient receptor potential channel A1 and mechanosensitive two pore-domain K+ channels between the lumbar splanchnic and pelvic nerve innervations of mouse urinary bladder and colon.</a> Neuroscience. 186, 179-187 (2001).</li><li>Wang, G., Tang, B., Traub, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+processing+of+noxious+colonic+input+by+thoracolumbar+and+lumbosacral+dorsal+horn+neurons+in+the+rat.">Differential processing of noxious colonic input by thoracolumbar and lumbosacral dorsal horn neurons in the rat.</a> J Neurophysiol. 94 (6), 3788-3794 (2005).</li></ol>

The protocol presented here is a relatively straightforward experimental method to assess the electrophysiological properties of the colonic afferents of rats. The protocol (from tissue dissection to setting up the nerve recording) usually takes about 2 h to complete. Tissue collection (step 3) and preparation of the suction electrode (step 5) are the critical steps. It is crucial to be able to locate the PG, the LSN, and the PN and to take care not to damage the ganglion and nerves during tissue dissection. The tip of t...

The gastrointestinal tract (GIT) is richly innervated with extrinsic afferent nerves that convey sensory signals from the gut to the central nervous system and that contribute to the gut-brain interaction. Altered excitability of these extrinsic afferents, as well as altered central processing of the afferent inputs, underlies visceral pain and other symptoms of GI conditions, including functional and inflammatory bowel diseases1. Sensory information from the colorectum is conveyed primarily through the thoracolumbar/hypogastric and the lumbosacral/pelvic nerves (PN)2. There has been an increased interest in studying the electrophysiological properties of these primary afferent fibers in rodent disease models. However, in vivo electrophysiological recordings of the colonic afferents in rodents is a technical challenge and requires considerable surgical skills. In addition, hemodynamic changes, tissue movement, and anesthetics may also impact nerve activity and sensitivity to test stimuli in vivo. Therefore, in recent years, an increasing number of studies have employed in vitro (ex vivo) preparations of different species, including mice, rats, guinea pigs, and humans, to examine the mechanisms of sensory transduction in colonic afferents and the altered excitability in disease conditions.3,4,5,6,7,8
Two types of ex vivo colonic preparation have primarily been reported: the &#34;flat-sheet&#34; preparation5,9,10 and the &#34;tube&#34; preparation3,4. A video protocol for the &#34;flat-sheet&#34; murine colorectum preparation has been previously published11. In this protocol, the mouse colorectum, with the PN) or lumbar splanchnic nerves (LSN) attached, is harvested and superfused in a tissue chamber. The colorectum is cut open longitudinally, and the nerve bundle is extended into a recording compartment filled with paraffin oil. Nerve activity is recorded using a monopolar platinum-iridium electrode. The protocol allows for the identification of the receptive fields of individual afferent fibers by using unbiased electrical stimulation. It localizes the application of chemical stimuli, as well as the application of different mechanical stimulation paradigms (e.g., focal mucosal probing and circumferential stretch), to the afferent nerve endings. Because the nerve must be extended to a separate chamber from the tissue chamber, it is critical to keep the attached nerve relatively long; the successful dissection of the nerves poses a challenge to those new to this methodology. More recently, Nullens et al. published a video protocol for the in vitro recording of the mesenteric afferents in murine jejunal and colonic segments12. In this &#34;tube&#34; preparation, the gut segment with the mesentery attached is kept intact, thus allowing for graded distension and the intra- and extra-luminal administration of different chemicals. Since the mesentery nerve is recorded using a suction electrode, which can be positioned close to the tissue, afferent activity can be recorded even though the mesentery nerve is relatively short. However, the mesentery nerve consists of mixed populations of vagal and spinal afferent fibers that innervate the jejunum or thoracolumbar hypogastric. Lumbosacral pelvic afferents innervate the colorectum, which cannot be discriminated in this protocol. Here, we present a detailed protocol for the electrophysiological recording of rat colonic afferents using the &#34;tube&#34; colorectum preparation with an intact PG. This method may allow for the characterization of the functional properties of lumbar splanchnic (hypogastric) and lumbosacral pelvic afferents.

<table width="889">
	<tbody>
		<tr height="40">
			<td height="40" style="width:215px;height:40px;">Sodium Pentobarbital</td>
			<td style="width:123px;">Shanghai Westang Bio-Tech</td>
			<td style="width:344px;">B558</td>
			<td style="width:208px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Capsaicin</td>
			<td>Sigma</td>
			<td>M2028</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Electrode puller</td>
			<td>MicroData Instrument Inc</td>
			<td>PMP107</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Neurolog System (Bioamplifier)</td>
			<td>Digitimer, Ltd</td>
			<td>Neurolog System</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">A/D converter</td>
			<td>Cambridge Electronic Design</td>
			<td>Micro1401</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Data processing software</td>
			<td>Cambridge Electronic Design</td>
			<td>Spike2 version 6</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Silver wire</td>
			<td>World Precision Instruments</td>
			<td>EP12</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Glass tubes</td>
			<td>World Precision Instruments</td>
			<td>1B150-4</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Electrode holder</td>
			<td>World Precision Instruments</td>
			<td>MEH3SBW</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Heating bath</td>
			<td>Grant</td>
			<td>GR150</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Dissecting microscope</td>
			<td>Leica</td>
			<td>Zoom2000</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Dissecting microscope</td>
			<td>World Precision Instruments</td>
			<td>PZMIII-BS</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Cigarette lighter</td>
			<td>any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Surgical tools</td>
			<td>World Precision Instruments</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Insect pins</td>
			<td>home-made from 0.1 mm stainless steel wire</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Three way manipulator</td>
			<td>World Precision Instruments</td>
			<td>KITF-R</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Rats</td>
			<td>Any</td>
			<td>NA</td>
			<td>Any strain/sex can be used.</td>
		</tr>
	</tbody>
</table>

in vitro characterization of the electrophysiological properties of colonic afferent fibers in rats

Dysfunction of the colonic sensory nerves has been implicated in the pathophysiology of several common conditions, including functional and inflammatory bowel diseases and diabetes. Here, we describe a protocol for the in vitro characterization of the electrophysiological properties of colonic afferents in rats. The colorectum, with the intact pelvic ganglion (PG) attached, is removed from the rat; superfused with carbogenated Krebs solution in the recording chamber; and cannulated at the oral and anal ends to allow for distension. A fine nerve bundle emanating from the PG is identified, and the multiunit afferent nerve activity is recorded using a suction electrode. Distension of the colonic segment elicits gradual increases in multiunit discharge. A principal component analysis is conducted to differentiate the low-threshold, the high-threshold, and the wide-dynamic range afferent fibers. Chemical sensitivity of colonic afferents can be studied through the bath or intraluminal administration of test compounds. This protocol can be modified for application to other species, such as mice and guinea pigs, and to study the differences in the electrophysiological properties of thoracolumbar/hypogastric and lumbosacral/pelvic afferents of the descending colon in normal and pathological conditions.

Figure 1 is the schematic illustration of the experimental setup for the ex vivo &#34;tube&#34; colorectum preparation, with a representative recording from a nerve distal to the PG. The nerve presumably contained a mixture of pelvic and lumbar splanchnic afferents. In preparations from normal rats, the colonic afferent nerves typically have a low level of irregular spontaneous activity. Ramp distension of the colon induces a gradual increase in the ...

Watch this Scientific Journal Video about In Vitro Characterization of the Electrophysiological Properties of Colonic Afferent Fibers in Rats at JoVE.com

In Vitro Characterization of the Electrophysiological Properties of Colonic Afferent Fibers in Rats

Abnormal sensory function underlies visceral pain and other symptoms of functional and inflammatory bowel diseases. A protocol for the electrophysiological recording of the colonic afferent nerves in an ex vivo rat colorectum preparation is presented here.

In Vitro Characterization of the Electrophysiological Properties of Colonic Afferent Fibers in Rats

Dysfunction of the colonic sensory nerves has been implicated in the pathophysiology of several common conditions, including functional and inflammatory ...

Research

JoVE Journal

Neuroscience

A General Method for Evaluating Incubation of Sucrose Craving in Rats

For someone on a food-restricted diet, food craving in response to food-paired cues may serve as a key behavioral transition point between abstinence and ...

Electrophysiological Characterization of GFP-Expressing Cell Populations in the Intact Retina

Studying the physiological properties and synaptic connections of specific neurons in the intact tissue is a challenge for those cells that lack ...

Visualization of Proprioceptors in Drosophila Larvae and Pupae

Visualization of Proprioceptors in Drosophila Larvae and Pupae

Proprioception is the ability to sense the motion, or position, of body parts by responding to stimuli arising within the body. In fruitflies and other ...

Dual Electrophysiological Recordings of Synaptically-evoked Astroglial and Neuronal Responses in Acute Hippocampal Slices

Astrocytes form together with neurons tripartite synapses, where they integrate and modulate neuronal activity. Indeed, astrocytes sense neuronal inputs ...

Selective Tracing of Auditory Fibers in the Avian Embryonic Vestibulocochlear Nerve

The embryonic chick is a widely used model for the study of peripheral and central ganglion cell projections. In the auditory system, selective labeling ...

Electrophysiological Recording in the Brain of Intact Adult Zebrafish

Previously, electrophysiological studies in adult zebrafish have been limited to slice preparations or to eye cup preparations and electrorentinogram ...

An In Vitro Adult Mouse Muscle-nerve Preparation for Studying the Firing Properties of Muscle Afferents

An In Vitro Adult Mouse Muscle-nerve Preparation for Studying the Firing Properties of Muscle Afferents

Muscle sensory neurons innervating muscle spindles and Golgi tendon organs encode length and force changes essential to proprioception. Additional ...

Electrophysiological and Morphological Characterization of Neuronal Microcircuits in Acute Brain Slices Using Paired Patch-Clamp Recordings

The combination of patch clamp recordings from two (or more) synaptically coupled neurons (paired recordings) in acute brain slice preparations with ...

In Vitro Recording of Mesenteric Afferent Nerve Activity in Mouse Jejunal and Colonic Segments

In Vitro Recording of Mesenteric Afferent Nerve Activity in Mouse Jejunal and Colonic Segments

Afferent nerves not only convey information concerning normal physiology, but also signal disturbed homeostasis and pathophysiological processes of the ...

Acute In Vivo Electrophysiological Recordings of Local Field Potentials and Multi-unit Activity from the Hyperdirect Pathway in Anesthetized Rats

Acute In Vivo Electrophysiological Recordings of Local Field Potentials and Multi-unit Activity from the Hyperdirect Pathway in Anesthetized Rats

Converging evidence shows that many neuropsychiatric diseases should be understood as disorders of large-scale neuronal networks. To better understand the ...