1.	Subject Recruitment and Consent
<ol>
<li>Following clinical evaluation and consent for subthalamic nucleus (STN) deep brain stimulation (DBS) for refractory Parkinson Disease, each patient's information is reviewed in order to determine if he/she meets the criteria for the intra-operative study (Defined in an Institutional Review Board approved protocol at the Massachusetts General Hospital).</li>
<li>If it is determined that the subject meets the study criteria, a physician member of the study group (not the operating surgeon) approaches the patient to discuss the possibility of participation in the study.</li>
<li>The consent form for participating in the study is then reviewed and explained to the subject. Importantly, the explanation of the study stresses that participation in the study is voluntary and that at any point he/she has the option to withdraw from participation. Moreover, it is then emphasized that their discussion to participate or to withdraw in the study has no impact on the medical care he/she will receive.</li>
<li>If it is determined that the subject understands and agrees to participate in the study, he/she signs the approved informed consent and is enrolled in the study.</li>
</ol>
2.	Behavioral Training and Rig Setup
<ol>
<li>As a part of DBS surgery for Parkinson Disease, subjects are admitted to the hospital one day prior to surgery. Hence, this offers an opportunity to train the subject on the behavioral task. This training is essential as it provides a time period during which the subject can learn to perform the task and develop comfort with its rules, removing "learning effects" confounds (Refer to discussion).</li>
<li>A portable behavioral rig is brought to the subject's hospital room on the night prior to surgery.</li>
<li>This rig is equipped with the exact same behavioral task which the subject is required to perform on the day of the intra-operative study.
<ol>
<li>In this example, the subject is asked to play a card game similar to the game of "war". In this game, the subject is required to bet (either $20 or $5) as to whether his or her card is higher than that of the computer. The intent of this task is to assay the role of reward and risk on neuronal encoding in the STN. In order to incentivize the subject they are told that they will be paid a proportion of their winnings.</li>
<li>As a means of reducing the potential combinations (and resulting confounds), only even-numbered cards of a single suit are used (e.g. 2, 4, 6, 8, and 10 of spades). As such, the potential outcomes and expectations of the task can be easily computed and analyzed.</li>
<li>In each trial, the subject first sees a screen depicting their randomly dealt card, and the back of the unknown computer's card. The screen then shows the two wager options, $5 and $20. Based on the relative strength of his/her card, the subject indicates the wager with a button push, after which the screen shows his/her card and the revealed computer's card. The final screen explicitly depicts the amount won or lost.</li>
</ol></li>
<li>The subject is allowed to play the game until they fully understand the rules of the game and perform at a comfortable level.</li>
</ol>
3.	Intra-operative - Experimental Setup
<ol>
<li>Once the subject has been positioned on the surgical table, the rig containing the behavioral, data acquisition and signal processing equipment is brought into the operating room. Rig positioning must take into consideration normal work flow and sterility issues related to the operating room setting.</li>
<li>As components of these rigs are assembled and disassembled for each recording session, it is vital to check all equipment connections. Therefore, as each component is connected to the data acquisition system, one must check the integrity of the data. These procedures should be done early in the surgery to prevent having to troubleshoot these issues during the critical recording time.
<ol>
<li>First, boot the acquisition and the signal processing equipment. Connect the outputs of the signal processing rig to the inputs of the acquisition rig. In the case of this study, we will be acquiring three extra-cellular action potential channels corresponding to three para-sagittally oriented electrodes that will be advanced into the subject's brain during the surgery. Turn on the amplifiers one at a time to ensure that the acquisition system is acquiring the signals.</li>
<li>Secure the monitor to the OR table in comfortable viewing position using an appropriate adapter.</li>
<li>If an input device (joystick, button box, keypad, etc.) is employed, position this device, paying attention to laterality relative to the side of the brain from which recordings will be obtained. Ensure that the subject's hand is comfortably positioned to operate the input device. Consider asking the anesthesiologist to secure the pulse oxygenation monitor on the other hand to ensure proper operation of the device. In this task we use a button box.</li>
<li>Boot the behavioral system and ensure that behavioral event markers are being captured by the acquisition rig.</li>
<li>Start the behavioral task and allow the subject to play a few trials of the task. During this time, ensure that the acquisition system is capturing the button box inputs and the behavioral markers generated by the behavioral rig.</li>
<li>If all the connections are functional, stop the behavioral task and acquisition rig.</li>
</ol></li></ol>
4.	Isolation of Subthalamic Nucleus Neurons
<ol>
<li>The objectives of the surgery are to place chronic DBS leads into the motor region of the STN. This placement is achieved through a combination of stereotactic imaging and neuophysiological recordings.</li>
<li>Details of the stereotactic planning and the surgical procedure itself will of course vary across institutions, but the general process is similar. At our institution, a Cosman-Roberts-Wells stereotactic frame and fiducial cage is applied and a head CT scan obtained. The CT with fiducials is merged with a previously obtained volumetric brain MRI on a neuro-navigation system (StealthStation, Medtronics, Minneapolis, MN; or BrainLab VectorVision, Feldkirchen, Germany). The coordinates of the target brain region (STN in this case) are converted to frame-based coordinates. In the operating room, the patient is positioned comfortably in a semi-reclined position, and prepped and draped using standard surgical technique. The coordinates of the left STN are programmed into the frame, which is positioned on the patient. The skin is incised and retracted. Burr holes are placed, and a small dural opening created. Cannulae attached to a microdrive are brought into position and advanced until the tip of the cannulae are 25 mm above target.</li>
<li>Once the cannulae are advanced into the brain, the internal stylets are removed and replaced with high-impedance (0.3 - 1 mega-Ohm) microelectrodes (FHC, Bowdoin, ME). The signal processing rig's pre-amplifiers are connected to each electrode and the differential reference channel is connected to the outer cannula.</li>
<li>On the signal-processing rig the amplifiers are turned on and the extra-cellular signal is assessed. In addition, the impedance for each electrode is checked before advancing further into the brain.</li>
<li>The surgeon advances the electrodes slowly ( 0.05-0.4 mm steps) into the brain. The electrodes are advanced starting 25mm from the calculated target towards the STN. This trajectory results in the electrode passing through the caudate nucleus, the thalamus, the zona inserta, and finally into the STN.</li>
<li>Once the electrodes have entered the STN, the physiologist manipulates the patient's contralateral limbs as a means of establishing whether the neuronal signal is motor responsive. When the surgeon and experimenter are satisfied with the electrodes' position, the behavioral task can be started.</li>
</ol>
5.	Data Acquisition
<ol>
<li>Before starting the behavioral task, it is important to document the depth of the microelectrodes and the motor responsiveness of the isolated neuron(s).</li>
<li>The subject is then instructed that the task will begin. Ensure that the button box is still comfortably positioned and that the monitor completely visible.</li>
<li>Start the data acquisition and acquire baseline activity for at least 1 minute prior to starting the behavioral task.</li>
<li>As the subject performs the task it is important to monitor the captured data. With any disruption in the acquisition, the task should be stopped and the problem rectified.</li>
<li>In the current study, the subject is asked to perform 120 trials for each STN depth.</li>
<li>The tasks can be performed multiple times for each depth in the STN; however, there are limitations to the duration of these intra-operative studies (described further in the discussion). We limit experimental recording time to 30 minutes to prevent patient discomfort and undue prolongation of surgery. Moreover, the subject has the opportunity to reject further recordings at any time, in which case the behavioral task is stopped and surgery resumes.</li>
<li>Once the study is completed, the data is backed up and archived for subsequent analysis.</li>
</ol>
6.	Data Analysis
<ol>
<li>First, the neuronal signals are discriminated into individual spike timestamps using commercially available software.</li>
<li>The behavioral task codes are then parsed, and the neuronal activity timestamps are aligned using code scripted in Matlab.</li>
</ol>
Representative Results:
Figure 1 depicts representative results from a single STN neuron recorded during the War game described above. The top panels depict rasters centered on four behaviorally relevant epochs in the task: the fixation period prior to each trial, presentation of the subject's card, the button press indicating the subject's wager, and presentation of the computer's card. The bottom panels represent binned (50 ms bins) peri-stimulus time histograms (PSTHs). This neuron does not respond robustly to presentation of the subject's card, but increases its firing significantly around the button push. This activity lasts until the computer's card is revealed, at which point firing decreases to baseline levels.
 <img src="/files/ftp_upload/2156/2156fig1.jpg" alt="Figure 1" /> 
Figure 1. Representative STN neuron. Rasters (top panels) and peri-stimulus time histograms (PSTHs) centered on behaviorally relevant epochs are depicted for a representative single STN neuron. This neuron's firing increases significantly around the time of the button push indicating the subject's wager.

<ol>
	<li>Benabid, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combined+(thalamotomy+and+stimulation)+stereotactic+surgery+of+the+VIM+thalamic+nucleus+for+bilateral+Parkinson+disease.">Combined (thalamotomy and stimulation) stereotactic surgery of the VIM thalamic nucleus for bilateral Parkinson disease.</a> Appl. Neurophysiol. 50 (1-6), 344-344 (1987).</li><li>Deuschl, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+randomized+trial+of+deep-brain+stimulation+for+Parkinson's+disease.">A randomized trial of deep-brain stimulation for Parkinson's disease.</a> N. Engl. J. Med. 355 (9), 896-896 (2006).</li><li>Gale, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+symphony+to+cacophony:+Pathophysiology+of+the+human+basal+ganglia+in+Parkinson+disease.">From symphony to cacophony: Pathophysiology of the human basal ganglia in Parkinson disease.</a> Neurosci. Biobehav. Rev. , (2007).</li><li>Williams, Z. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+anterior+cingulate+neurons+and+the+integration+of+monetary+reward+with+motor+responses.">Human anterior cingulate neurons and the integration of monetary reward with motor responses.</a> Nat. Neurosci. 7 (12), 1370-1370 (2004).</li><li>Zaghloul, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+substantia+nigra+neurons+encode+unexpected+financial+rewards.">Human substantia nigra neurons encode unexpected financial rewards.</a> Science. 323 (5920), 1496-1496 (2009).</li></ol>

No conflicts of interest declared.

Deep Brain Stimulation surgery offers a valuable opportunity to examine the activity of individual neurons in the human brain. To date this opportunity has permitted numerous descriptive studies that characterize the activities of different deep nuclei. More recently, intra-operative tasks have become more sophisticated in order to address various aspects of behavior and cognition. The intent of the current protocol is to provide a guide for implementing successful intra-operative behavioral tasks. The goals of the ta...

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		<div>
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		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Behavioral Rig</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>PC with dual Video Out</td>
<td>&nbsp;</td>
<td>Dell Computers*</td>
<td>Optiplex 745</td>
<td>&nbsp;</td>
<tr>
<td>Digital Boards</td>
<td>&nbsp;</td>
<td>National Instruments**</td>
<td>PCI-6229</td>
<td>&nbsp;</td>
<tr>
<td>Connector Board</td>
<td>&nbsp;</td>
<td>National Instruments**</td>
<td>BNC-2090a</td>
<td>&nbsp;</td>
<tr>
<td>Software</td>
<td>&nbsp;</td>
<td>The MathWorks</td>
<td>Matlab 2007b***</td>
<td>&nbsp;</td>
<tr>
<td>Behavioral Software</td>
<td>&nbsp;</td>
<td>Eskandar Lab</td>
<td><a href="www.Monkeylogic.net">www.Monkeylogic.net</a></td>
<td>&nbsp;</td>
<tr>
<td>Acquisition Rig</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>PC</td>
<td>&nbsp;</td>
<td>Dell Computers *</td>
<td>Optiplex 745</td>
<td>&nbsp;</td>
<tr>
<td>Digital Boards</td>
<td>&nbsp;</td>
<td>Cambridge Electronic Designs*</td>
<td>Power 1401</td>
<td>&nbsp;</td>
<tr>
<td>Software</td>
<td>&nbsp;</td>
<td>Cambridge Electronic Designs*</td>
<td>Spike2</td>
<td>&nbsp;</td>
<tr>
<td>Signal Processing</td>
<td>&nbsp;</td>
<td>Alpha-Omega Engineering*</td>
<td>Micro-Guide Pro</td>
<td>&nbsp;</td>
<tr>
<td>Analysis</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Neuonal Signal post-processing</td>
<td>&nbsp;</td>
<td>Plexon *</td>
<td>Offline Sorter</td>
<td>&nbsp;</td>
<tr>
<td>Software</td>
<td>&nbsp;</td>
<td>The MathWorks *</td>
<td>Matlab 2007b</td>
<td>&nbsp;</td>
<tr>
<td>Button Box</td>
<td>&nbsp;</td>
<td>Refer to 'Button Assembly'</td>
<td>&nbsp;</td>
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			*Denotes that this items can be substitute for by comparable equipment or software; 
** Denotes that substitute National Instruments components can be used (refer to <a href="www.Monkeylogic.net">www.Monkeylogic.net</a> for compatibility); 
*** Refer to <a href="www.Monkeylogic.net">www.Monkeylogic.net</a> for specific required Matlab toolboxs.		</div>

intra-operative behavioral tasks in awake humans undergoing deep brain stimulation surgery

Deep brain stimulation (DBS) is a surgical procedure that directs chronic, high frequency electrical stimulation to specific targets in the brain through implanted electrodes. Deep brain stimulation was first implemented as a therapeutic modality by Benabid et al. in the late 1980s, when he used this technique to stimulate the ventral intermediate nucleus of the thalamus for the treatment of tremor 1. Currently, the procedure is used to treat patients who fail to respond adequately to medical management for diseases such as Parkinson's, dystonia, and essential tremor. The efficacy of this procedure for the treatment of Parkinson's disease has been demonstrated in well-powered, randomized controlled trials 2. Presently, the U.S. Food and Drug Administration has approved DBS as a treatment for patients with medically refractory essential tremor, Parkinson's disease, and dystonia. Additionally, DBS is currently being evaluated for the treatment of other psychiatric and neurological disorders, such as obsessive compulsive disorder, major depressive disorder, and epilepsy. 
DBS has not only been shown to help people by improving their quality of life, it also provides researchers with the unique opportunity to study and understand the human brain. Microelectrode recordings are routinely performed during DBS surgery in order to enhance the precision of anatomical targeting. Firing patterns of individual neurons can therefore be recorded while the subject performs a behavioral task. Early studies using these data focused on descriptive aspects, including firing and burst rates, and frequency modulation 3. More recent studies have focused on cognitive aspects of behavior in relation to neuronal activity 4,5. This article will provide a description of the intra-operative methods used to perform behavioral tasks and record neuronal data with awake patients during DBS cases. Our exposition of the process of acquiring electrophysiological data will illuminate the current scope and limitations of intra-operative human experiments.

Watch this Scientific Journal Video about Intra-Operative Behavioral Tasks in Awake Humans Undergoing Deep Brain Stimulation Surgery at JoVE.com

Intra-Operative Behavioral Tasks in Awake Humans Undergoing Deep Brain Stimulation Surgery

Deep brain stimulation surgery offers a unique opportunity to examine information encoding in the awake human brain. This article will describe intra-operative methods used to perform cognitive and behavioral tasks while simultaneously acquiring physiological data such as EMG, single-unit neuronal activity and/or local field potentials.

Deep brain stimulation (DBS) is a surgical procedure that directs chronic, high frequency electrical stimulation to specific targets in the brain through ...

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12.9K Views.  Harvard Medical School. Deep brain stimulation surgery offers a unique opportunity to examine information encoding in the awake human brain. This article will describe intra-operative methods used to perform cognitive and behavioral tasks while simultaneously acquiring physiological data such as EMG, single-unit neuronal activity and/or local field potentials.

Video: Intra-Operative Behavioral Tasks in Awake Humans Undergoing Deep Brain Stimulation Surgery

Excitotoxic Stimulation of Brain Microslices as an In vitro Model of Stroke

Examining molecular mechanisms involved in neuropathological conditions, such as ischemic stroke, can be difficult when using whole animal systems. As such, primary or &#39;neuronal-like&#39; cell culture systems are commonly utilized. While&#160;these systems are relatively easy to work with, and are useful model systems in which various functional outcomes (such as cell death) can be readily quantified, the examined outcomes and pathways in cultured immature neurons (such as excitotoxicity-mediated cell death pathways) are not necessarily the same as those observed in mature brain, or in intact tissue. Therefore, there is the need to develop models in which cellular mechanisms in mature neural tissue can be examined. We have developed an in vitro technique that can be used to investigate a variety of molecular pathways in intact nervous tissue. The technique described herein utilizes rat cortical tissue, but this technique can be adapted to use tissue from a variety of species (such as mouse, rabbit, guinea pig, and chicken) or brain regions (for example, hippocampus, striatum, etc.). Additionally, a variety of stimulations/treatments can be used (for example, excitotoxic, administration of inhibitors, etc.). In conclusion, the brain slice model described herein can be used to examine a variety of molecular mechanisms involved in excitotoxicity-mediated brain injury.

Excitotoxic Stimulation of Brain Microslices as an In vitro Model of Stroke

We have developed a brain slice model which can be used to examine molecular mechanisms involved in excitotoxicity-mediated brain injury.&#160;This technique generates viable mature brain tissue and reduces animal numbers required for experimentation, whilst keeping the neuronal circuitry, cellular interactions, and postsynaptic compartments partly intact.

Examining molecular mechanisms involved in neuropathological conditions, such as ischemic stroke, can be difficult when using whole animal systems. As ...

Controlling Parkinson's Disease With Adaptive Deep Brain Stimulation

Adaptive deep brain stimulation (aDBS) has the potential to improve the treatment of Parkinson&#39;s disease by optimizing stimulation in real time according to fluctuating disease and medication state. In the present realization of adaptive DBS we record and stimulate from the DBS electrodes implanted in the subthalamic nucleus of patients with Parkinson&#39;s disease in the early post-operative period. Local field potentials are analogue filtered between 3 and 47 Hz before being passed to a data acquisition unit where they are digitally filtered again around the patient specific beta peak, rectified and smoothed to give an online reading of the beta amplitude. A threshold for beta amplitude is set heuristically, which, if crossed, passes a trigger signal to the stimulator. The stimulator then ramps up stimulation to a pre-determined clinically effective voltage over 250 msec and continues to stimulate until the beta amplitude again falls down below threshold. Stimulation continues in this manner with brief episodes of ramped DBS during periods of heightened beta power.
Clinical efficacy is assessed after a minimum period of stabilization (5 min) through the unblinded and blinded video assessment of motor function using a selection of scores from the Unified Parkinson&#39;s Rating Scale (UPDRS). Recent work has demonstrated a reduction in power consumption with aDBS as well as an improvement in clinical scores compared to conventional DBS. Chronic aDBS could now be trialed in Parkinsonism.

Controlling Parkinson&#039;s Disease With Adaptive Deep Brain Stimulation

Adaptive deep brain stimulation (aDBS) is effective for Parkinson&#8217;s disease, improving symptoms and reducing power consumption compared to conventional deep brain stimulation (cDBS). In aDBS we track a local field potential biomarker (beta oscillatory amplitude) in real time and use this to control the timing of stimulation.

Adaptive deep brain stimulation (aDBS) has the potential to improve the treatment of Parkinson&#39;s disease by optimizing stimulation in real time ...

Using Saccadometry with Deep Brain Stimulation to Study Normal and Pathological Brain Function

The oculomotor system involves a large number of brain areas including parts of the basal ganglia, and various neurodegenerative diseases including Parkinson's and Huntington's can disrupt it. People with Parkinson's disease, for example, tend to have increased saccadic latencies. Consequently, the quantitative measurement of saccadic eye movements has received considerable attention as a potential biomarker for neurodegenerative conditions. A lot more can be learned about the brain in both health and disease by observing what happens to eye movements when the function of specific brain areas is perturbed. Deep brain stimulation is a surgical intervention used for the management of a range of neurological conditions including Parkinson's disease, in which stimulating electrodes are placed in specific brain areas including several sites in the basal ganglia. Eye movement measurements can then be made with the stimulator systems both off and on and the results compared. With suitable experimental design, this approach can be used to study the pathophysiology of the disease being treated, the mechanism by which DBS exerts it beneficial effects, and even aspects of normal neurophysiology.

This paper describes the use of quantitative measurement of eye movements in conjunction with stimulation of focal areas of the deep brain in order to study physiology, pathophysiology, and the mechanisms of deep brain stimulation.

The oculomotor system involves a large number of brain areas including parts of the basal ganglia, and various neurodegenerative diseases including ...

A Multimodal Imaging- and Stimulation-based Method of Evaluating Connectivity-related Brain Excitability in Patients with Epilepsy

Resting-state functional connectivity MRI (rs-fcMRI) is a technique that identifies connectivity between different brain regions based on correlations over time in the blood-oxygenation level dependent signal. rs-fcMRI has been applied extensively to identify abnormalities in brain connectivity in different neurologic and psychiatric diseases. However, the relationship among rs-fcMRI connectivity abnormalities, brain electrophysiology and disease state is unknown, in part because the causal significance of alterations in functional connectivity in disease pathophysiology has not been established. Transcranial Magnetic Stimulation (TMS) is a technique that uses electromagnetic induction to noninvasively produce focal changes in cortical activity. When combined with electroencephalography (EEG), TMS can be used to assess the brain's response to external perturbations. Here we provide a protocol for combining rs-fcMRI, TMS and EEG to assess the physiologic significance of alterations in functional connectivity in patients with neuropsychiatric disease. We provide representative results from a previously published study in which rs-fcMRI was used to identify regions with abnormal connectivity in patients with epilepsy due to a malformation of cortical development, periventricular nodular heterotopia (PNH). Stimulation in patients with epilepsy resulted in abnormal TMS-evoked EEG activity relative to stimulation of the same sites in matched healthy control patients, with an abnormal increase in the late component of the TMS-evoked potential, consistent with cortical hyperexcitability. This abnormality was specific to regions with abnormal resting-state functional connectivity. Electrical source analysis in a subject with previously recorded seizures demonstrated that the origin of the abnormal TMS-evoked activity co-localized with the seizure-onset zone, suggesting the presence of an epileptogenic circuit. These results demonstrate how rs-fcMRI, TMS and EEG can be utilized together to identify and understand the physiological significance of abnormal brain connectivity in human diseases.

Resting-state functional-connectivity MRI has identified abnormalities in patients with a wide range of neuropsychiatric disorders, including epilepsy due to malformations of cortical development. Transcranial Magnetic Stimulation in combination with EEG can demonstrate that patients with epilepsy have cortical hyperexcitability in regions with abnormal connectivity.

Resting-state functional connectivity MRI (rs-fcMRI) is a technique that identifies connectivity between different brain regions based on correlations ...

Symmetric Bihemispheric Postmortem Brain Cutting to Study Healthy and Pathological Brain Conditions in Humans

Neuropathologists, at times, feel intimidated by the amount of knowledge needed to generate definitive diagnoses for complex neuropsychiatric phenomena described in those patients for whom a brain autopsy has been requested. Although the advancements of biomedical sciences and neuroimaging have revolutionized the neuropsychiatric field, they have also generated the misleading idea that brain autopsies have only a confirmatory value. This false idea created a drastic reduction of autopsy rates and, consequently, a reduced possibility to perform more detailed and extensive neuropathological investigations, which are necessary to comprehend numerous normal and pathological aspects yet unknown of the human brain. The traditional inferential method of correlation between observed neuropsychiatric phenomena and corresponding localization/characterization of their possible neurohistological correlates continues to have an undeniable value. In the context of neuropsychiatric diseases, the traditional clinicopathological method is still the best possible methodology (and often the only available) to link unique neuropsychiatric features to their corresponding neuropathological substrates, since it relies specifically upon the direct physical assessment of brain tissues. The assessment of postmortem brains is based on brain cutting procedures that vary across different neuropathology centers. Brain cuttings are performed in a relatively extensive and systematic way based on the various clinical and academic contingencies present in each institution. A more anatomically inclusive and symmetric bi-hemispheric brain cutting methodology should at least be used for research purposes in human neuropathology to coherently investigate, in depth, normal and pathological conditions with the peculiarities of the human brain (i.e., hemispheric specialization and lateralization for specific functions). Such a method would provide a more comprehensive collection of neuropathologically well-characterized brains available for current and future biotechnological and neuroimaging techniques. We describe a symmetric bi-hemispheric brain cutting procedure for the investigation of hemispheric differences in human brain pathologies and for use with current as well as future biomolecular/neuroimaging techniques.

Organized brain cutting procedures are necessary to correlate specific neuropsychiatric phenomena with definitive neuropathologic diagnoses. Brain cuttings are performed differently based on various clinico-academic contingencies. This protocol describes a symmetric bihemispheric brain cutting procedure to investigate hemispheric differences in human brain pathologies and to maximize current and future biomolecular/neuroimaging techniques.

Neuropathologists, at times, feel intimidated by the amount of knowledge needed to generate definitive diagnoses for complex neuropsychiatric phenomena ...

Evaluating the Procedure for Performing Awake Cystometry in a Mouse Model

Awake filling cystometry has been used for a long time to evaluate bladder function in freely moving mice, however, the specific methods used, vary among laboratories. The goal of this study was to describe the microsurgical procedure used to implant an intravesical tube and the experimental technique for recording urinary bladder pressure in an awake, freely moving mouse. In addition, experimental data is presented to show how surgery, as well as tubing type and size, affect lower urinary tract function and recording sensitivity. The effect of tube diameter on pressure recording was assessed in both polyethylene and polyurethane tubing with different internal diameters. Subsequently, the best performing tube from both materials was surgically implanted into the dome of the urinary bladder of male C57BL/6 mice. Twelve-hour, overnight micturition frequency was recorded in healthy, intact animals and animals 2, 3, 5, and 7 days post-surgery. At harvest, bladders were assessed for signs of swelling using gross observation and were subsequently processed for pathological analysis. The greatest extent of bladder swelling was observed on day 2 and 3, which correlated with behavioral voiding data showing significantly impaired bladder function. By day 5, bladder histology and voiding frequency had normalized. Based on the literature and evidence provided by our studies, we propose the following steps for in vivo recording of intravesical pressure and voided volume in an awake mouse: 1) Perform the surgery using an operating microscope and microsurgical tools, 2) Use polyethylene-10 tubing to minimize movement artifacts, and 3) Perform cystometry on post-operative day 5, when bladder swelling resolves.

This study describes the surgical procedures and experimental techniques for performing awake cystometry in a freely moving mouse. In addition, it provides experimental evidence to support its optimization and standardization.

Awake filling cystometry has been used for a long time to evaluate bladder function in freely moving mice, however, the specific methods used, vary among ...

A Quantitative Sensory Testing Paradigm to Obtain Measures of Pain Processing in Patients Undergoing Breast Cancer Surgery

Chronic pain following surgery, persistent postsurgical pain, is an important highly prevalent condition contributing to significant symptom burden and lower quality of life. Persistent postsurgical pain is relatively refractory to treatment hence generating a high need for preventive strategies and treatments. Therefore, the identification of patients at risk of developing persistent pain is an area of active ongoing research. Recently it was demonstrated that peri-operative disruptions in central pain processing may be able to predict persistent postsurgical pain at long term follow-up in breast cancer patients. The aim of the current report is to present a short protocol to obtain pain thresholds to different stimuli at multiple sites and a measure of endogenous analgesia in breast cancer patients. We have used this method successfully in a clinical context and detail some representative results from a clinical study.

Persistent postsurgical pain may be related to changes in pain processing. By assessing pain in response to standardized stimuli, changes in pain processing can be elucidated. We present methods to obtain pain thresholds to different stimuli and a measure of endogenous analgesia in patients undergoing breast cancer surgery.

Chronic pain following surgery, persistent postsurgical pain, is an important highly prevalent condition contributing to significant symptom burden and ...

Spinal Cord Lateral Hemisection and Asymmetric Behavioral Assessments in Adult Rats

Incomplete spinal cord injury (SCI) often leads to impairments of sensorimotor functions and is clinically the most frequent type of SCI. Human Brown-S&#233;quard syndrome&#160;is a common type of incomplete SCI caused by a lesion to one half of the spinal cord which results in paralysis and loss of&#160;proprioception&#160;on the same (or ipsilesional) side as the injury, and loss of pain and temperature sensation on the opposite (or contralesional) side. Adequate methodologies for producing a spinal cord lateral hemisection (HX) and assessing neurological impairments are essential to establish a reliable animal model of Brown-S&#233;quard syndrome. Although lateral hemisection model plays a pivotal role in basic and translational research, standardized protocols for creating such a hemisection and assessing unilateralized function are lacking. The goal of this study is to describe step-by-step procedures to produce a rat spinal lateral HX at the 9th thoracic (T9) vertebral level. We, then, describe a combined behavior scale for HX (CBS-HX) that provides a simple and sensitive assessment of asymmetric neurological performance for unilateral SCI. The CBS-HX, ranging from 0 to 18, is composed of 4 individual assessments which include unilateral hindlimb stepping (UHS), coupling, contact placing, and grid walking. For CBS-HX, the ipsilateral and contralateral hindlimbs are assessed separately. We found that, after a T9 HX, the ipsilateral hindlimb showed impaired behavior function whereas the contralateral hindlimb showed substantial recovery. The CBS-HX effectively discriminated behavioral functions between ipsilateral and contralateral hindlimbs and detected temporal progression of recovery of the ipsilateral hindlimb. The CBS-HX components can be analyzed separately or in combination with other measures when needed. Although we only provided visual descriptions of the surgical procedures and behavioral assessments of a thoracic HX, the principle may be applied to other incomplete SCIs and at other levels of the injury.

Here we describe surgical procedures to produce a reliable spinal cord lateral hemisection (HX) at the 9th thoracic level in adult rats and neurobehavioral assessments designed for detecting asymmetric deficits after such a unilateral injury.

Incomplete spinal cord injury (SCI) often leads to impairments of sensorimotor functions and is clinically the most frequent type of SCI. Human ...

Intra-Operative Neural Monitoring of Thyroid Surgery in a Porcine Model

Intraoperative injury to the recurrent laryngeal nerve (RLN) can cause vocal cord paralysis, which interferes with speech and can potentially interfere with breathing. In recent years, intraoperative neural monitoring (IONM) has been widely adapted as an adjunct technique to localize the RLN, detect RLN injury, and predict vocal cord function during the operations. Many studies have also used animal models to investigate new applications of IONM technology and to develop reliable strategies for preventing intraoperative RLN injury. The aim of this article is to introduce a standard protocol for using a porcine model in IONM research. The article demonstrates the procedures for inducing general anesthesia, performing tracheal intubation, and experimental design to investigate the electrophysiological characteristics of RLN injuries. Applications of this protocol can improve overall efficacy in implementing the 3R principle (replacement, reduction and refinement) in porcine IONM studies.

This study aims to develop a standard protocol of intra-operative neural monitoring of thyroid surgery in a porcine model. Here, we present a protocol to demonstrate general anesthesia, to compare different types of electrodes, and to investigate the electrophysiological characteristics of the normal and injured recurrent laryngeal nerves.

Intraoperative injury to the recurrent laryngeal nerve (RLN) can cause vocal cord paralysis, which interferes with speech and can potentially interfere ...

Updated Technique for Reliable, Easy, and Tolerated Transcranial Electrical Stimulation Including Transcranial Direct Current Stimulation

Transcranial direct current stimulation (tDCS) is a noninvasive method of neuromodulation using low-intensity direct electrical currents. This method of brain stimulation presents several potential advantages compared to other techniques, as it is noninvasive, cost-effective, broadly deployable, and well-tolerated provided proper equipment and protocols are administered. Even though tDCS is apparently simple to perform, correct administration of the tDCS session, especially the electrode positioning and preparation, is vital for ensuring reproducibility and tolerability. The electrode positioning and preparation steps are traditionally also the most time consuming and error-prone. To address these challenges, modern tDCS techniques, using fixed-position headgear and pre-assembled sponge electrodes, reduce complexity and setup time while also ensuring that the electrodes are consistently placed as intended. These modern tDCS methods present advantages for research, clinic, and remote-supervised (at home) settings. This article provides a comprehensive step-by-step guide for administering a tDCS session using fixed-position headgear and pre-assembled sponge electrodes. This guide demonstrates tDCS using commonly applied montages intended for motor cortex and dorsolateral prefrontal cortex (DLPFC) stimulation. As described, selection of the head size and montage-specific headgear automates electrode positioning. Fully assembled pre-saturated snap-electrodes are simply affixed to the set position snap-connectors on the headgear. The modern tDCS method is shown to reduce setup time and reduce errors for both novice and expert operators. The methods outlined in this article can be adapted to different applications of tDCS as well as other forms of transcranial electrical stimulation (tES) such as transcranial alternating current stimulation (tACS) and transcranial random noise stimulation (tRNS). However, since tES is application specific, as appropriate, any methods recipe is customized to accommodate subject, indication, environment, and outcome specific features.

When administering transcranial direct current stimulation (tDCS), reproducible electrode preparation and placement are vital for a tolerated and effective session. The purpose of this article is to demonstrate updated modern setup procedures for the administration of tDCS and related transcranial electrical stimulation techniques, such as transcranial alternating current stimulation (tACS).

Transcranial direct current stimulation (tDCS) is a noninvasive method of neuromodulation using low-intensity direct electrical currents. This method of ...