The authors would like to thank Qiuli Wang, Language Resource Center, Colby College, for technical assistance with video processing and Eric Thomas, department of music, Colby College, for providing the background music. This project was supported by grants from the National Center for Research Resources, INBRE (P20RR016463-12), the National Institute for General Medical Sciences (P20 GM103423-12), Nationals Institutes of Health and Science Division Grant, Colby College (STA). JL and LWM were supported by grants from Summer Scholar Fund, Colby College.

1. Drosophila Startle-induced Locomotion Assay
<ol>
	<li>Drug Treatment
	<ol>
		<li>Sedate to immobilize desired number (approximately 8-12) of 1-3 day-old male flies using CO2 and transport them to vials containing the drug-supplemented food. Note: Another anesthetic e.g., ether or ice can be used to sedate flies to enable counting and handling.</li>
		<li>Allow flies to recover from sedation for 20 min (or until recovery) with the vial in a horizontal position (to prevent flies getting stuck on food) and then place the vial upright in a 12 hr dark, 12 hr light incubator at 25 &#176;C for the remainder of the experiment.</li>
	</ol>
	</li>
	<li>Experimental Set Up
	<ol>
		<li>Divide this double vial setup into three equal sections of 6.33 cm by marking circles around the vials with a permanent marker.</li>
		<li>After 3 days of drug exposure, transfer flies without anesthetizing into the bottom vial and quickly place the top vial over the opening. Tape the two vials together with clear tape.</li>
		<li>Allow flies to acclimate to the new environment for 15 min.</li>
		<li>Place vials on a white background and set up a digital camera at an appropriate distance from the double vial apparatus with a timer in view. Ensure the entire apparatus is visible in a single picture frame and that all flies are in focus. To maintain consistent frames between trials, mark the location of camera and vial.</li>
	</ol>
	</li>
	<li>Mobility Assay
	<ol>
		<li>Clearly display the trial number, drug treatment, and timer in camera view.</li>
		<li>Firmly tap the double vial apparatus against the countertop 3 times and ensure that all flies fall to the bottom of the vial. Simultaneously start the timer.</li>
		<li>Every 5 sec for 1 min, take a picture of the apparatus. Note: Alternatively, a video could be captured and paused at appropriate intervals for measurements.</li>
		<li>Allow flies to recover undisturbed for 1 min.</li>
		<li>Repeat 2 more times with 1 min recovery time between each trial. Note: Each apparatus should take 5 min to complete data collection. Maintain similar force of tapping between trials. Multiple (at least 3) apparatus can be easily handled simultaneously.</li>
	</ol>
	</li>
	<li>Data Analysis
	<ol>
		<li>Review pictures and record the number of flies in each section over time. Calculate the percentage of flies in each section over time. Notes: Repeat this entire procedure with the same flies at 2 or 3 time points of interest, for example, day 3, 5, and 7. If too many flies die throughout the experiment it is possible to scale up the original trial number to compensate for the mortality. Use appropriate statistical analysis to compare the data.</li>
	</ol>
	</li>
</ol>
2. Drosophila Spontaneous Locomotion Assay
<ol>
	<li>Food Preparation
	<ol>
		<li>Reconstitute 3 g of instant Drosophila medium with 15 ml of de-ionized water and desired rotenone (or another drug of interest) dosage.</li>
		<li>Once the food mixture has become firm (about 5 min), carefully load the food to be approximately 1 cm high into manufacturer supplied transparent tubes (5 mm X 65 mm). Add the drug infused food to the tubes by carefully placing the tubes vertically in the food and twisting them until they can be removed with the food inside the tube. Note: It is helpful to place a finger on the opening of the tube to create a vacuum. Food should not contain any air bubbles or have an uneven surface as the flies can become stuck.</li>
	</ol>
	</li>
	<li>Experimental Setup
	<ol>
		<li>Place a plastic cap on the end of tube nearest the food. Push the plastic cap on the tube as little as possible, as it can create an air bubble in the vial if pushed to forcefully.</li>
		<li>Sedate 1 day-old male flies using CO2 and carefully insert 1 male fly into each tube with a paintbrush. Repeat depending on the number of desired trials.</li>
		<li>Plug the end of the tube farthest from the food with a small cotton ball, which can be hand rolled from larger store bought cotton balls.</li>
		<li>Allow flies to recover with the tubes in a horizontal position for 15 min and ensure that all flies are alive and active. Insert the tubes into DAM and make sure that all the tubes are in the same position relative to DAM. Note: It is possible to place them with the area of monitoring at the middle of the vial, or to push all the vials to the side, so that the end of the tube is being monitored. Note: See discussion for variations on this method.</li>
	</ol>
	</li>
	<li>Data Collection
	<ol>
		<li>Place the DAM in a 12 hr dark, 12 hr light incubator set to 25 &#176;C. Connect the DAM to the data collection system. Open the DAM software and under preferences select bin length to 10 min. Start data collection and allow the program to collect data for 7 days. Note: Bin length can be adjusted if required.</li>
		<li>Data Analysis 
		Note: Process the data to obtain counts per min as a measure for long-term spontaneous locomotion.
		<ol>
			<li>Open DAM file scan program and access monitor data by clicking select input data.</li>
			<li>Select appropriate monitor range and select bin length to 10 min intervals.</li>
			<li>In output file type choose channel files. Leave all other options as default.</li>
			<li>Click scan data and save to a designated folder.</li>
			<li>Import data in a circadian data analysis software to obtain counts per min. Note: For data analysis Clocklab software is commonly used. Other options are also available.</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>

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The authors have nothing to disclose.

In this study, we describe two procedures for measuring both long-term spontaneous locomotion and short-term startle-induced locomotion in a rotenone-induced Drosophila model of Parkinson&#8217;s disease. One can also measure these locomotion characteristics in flies exposed to other pharmacological agents known to model Parkinson&#8217;s disease e.g., paraquat14, genetic models of Parkinson&#8217;s disease e.g., alpha-synuclein mutants15, and other fly models of diseases ...

Locomotion deficiencies are a major symptom of Parkinson&#8217;s disease and are largely caused by deterioration of dopaminergic neurons of the substantia nigra1. Rotenone is a ketonic insecticide that has been studied extensively to model Parkinson&#8217;s motor deficits in Drosophila2-6. Rotenone causes oxidative damage by blocking the oxidative phosphorylation pathway, which ultimately causes cell death7. Dopaminergic neurons are more prone to rotenone toxicity, making the effects of the chemical primarily motor based2,7. By inducing Parkinson&#8217;s disease symptoms in flies, we can better understand the disease and remedy its symptoms6,8-11. Drosophila provides a good model for studying this effect because they are genetically tractable, easy to maintain, and have a rapid life cycle.
Several studies have shown that rotenone causes short-term startle-induced locomotion defects in Drosophila&#8212;when flies are maintained on rotenone-supplemented food, they show a slower negative geotactic response after startle2-6. Their failure to climb upwards in a vial apparatus as quickly as control trials is indicative of startle-induced locomotion defects.
The effect of rotenone on long-term, spontaneous movement is not well described. Drosophila activity monitors (DAMs) have been successfully used to monitor movement in Drosophila circadian rhythm studies12,13. Flies are placed in individual tubes, which are loaded into the DAM. This apparatus is equipped with an infrared sensor, which counts the number of times a fly breaks the infrared beam. These counts can be used as a measure of undisturbed locomotion and activity12,13. By placing flies in a DAM, the effect of rotenone on their long-term locomotion can be characterized. This study describes methods to measure short-term startle-induced locomotion and long-term spontaneous locomotion in order to better understand the effects of rotenone mediated motor deficiencies. Characterization of locomotion deficiencies mimicking Parkinson&#8217;s disease are important because they allow for the study of other compounds which may reverse these locomotion defects.

<table border="0" cellpadding="0" cellspacing="0" width="628">
	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Standard narrow vials</td>
			<td style="width:127px;">Genesee Scientific</td>
			<td style="width:119px;">32-120</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Rotenone</td>
			<td style="width:127px;">Sigma</td>
			<td style="width:119px;">R8875</td>
			<td>Store in freezer, make fresh for each experiment</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Dimethyl Sulfoxide (DMSO)</td>
			<td style="width:127px;">Sigma</td>
			<td style="width:119px;">D8418</td>
			<td>Solvent for rotenone</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Instant Drosophila medium</td>
			<td style="width:127px;">Carolina Biological&#160;</td>
			<td style="width:119px;">Formula 4-24</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Drosophila activity monitor (DAM)</td>
			<td style="width:127px;">Trikinetics</td>
			<td style="width:119px;">DAM2</td>
			<td>trikinetics.com</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">DAM tubes</td>
			<td style="width:127px;">Trikinetics</td>
			<td style="width:119px;">Tubes 5X65 mm</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;"></td>
			<td style="width:127px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:216px;">Recipe for Rotenone +food (125 mM dose)</td>
			<td style="width:127px;"></td>
			<td style="width:119px;"></td>
			<td>Make 62.5 mM rotenone stock solution in DMSO by dissolving 25 mg rotenone in 1 ml DMSO&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:127px;"></td>
			<td style="width:119px;"></td>
			<td>For 125 mM dose, add 10 mM rotenone stock in DMSO to 5 ml water.</td>
		</tr>
	</tbody>
</table>

methods to characterize spontaneous and startle-induced locomotion in a rotenone-induced parkinson's disease model of drosophila

Parkinson&#8217;s disease is a neurodegenerative disorder that results from the degeneration of dopaminergic neurons in the central nervous system, primarily in the substantia nigra. The disease causes motor deficiencies, which present as rigidity, tremors and dementia in humans. Rotenone is an insecticide that causes oxidative damage by inhibiting the function of the electron transport chain in mitochondria. It is also used to model Parkinson&#8217;s disease in the Drosophila. Flies have an inherent negative geotactic response, which compels them to climb upwards upon being startled. It has been established that rotenone causes early mortality and locomotion defects that disrupt the flies&#8217; ability to climb after they have been tapped downwards. However, the effect of rotenone on spontaneous movement is not well documented. This study outlines two sensitive, reproducible, and high throughput assays to characterize rotenone-induced deficiencies in short-term startle-induced locomotion and long-term spontaneous locomotion in Drosophila. These assays can be conveniently adapted to characterize other Drosophila models of locomotion defects and efficacy of therapeutic agents.

Drosophila Startle-induced Locomotion Assay
Wildtype, canton-S, flies showed a robust negative geotactic response with only approximately 88% and 5% of flies in the top and bottom sections respectively, of the double-vial apparatus after 30 sec (Figure 1). Flies exposed to 125 &#956;M and 250 &#956;M rotenone for 3 days showed a slight decrease in the number of flies in the top section and slight increase in the number of fli...

Watch this Scientific Journal Video about Methods to Characterize Spontaneous and Startle-induced Locomotion in a Rotenone-induced Parkinson's Disease Model of Drosophila at JoVE.com

Methods to Characterize Spontaneous and Startle-induced Locomotion in a Rotenone-induced Parkinson&#039;s Disease Model of Drosophila

Parkinson&#8217;s disease is a neurodegenerative disorder that results from the degeneration of dopaminergic neurons in the central nervous system, causing locomotion defects. Rotenone models Parkinson&#8217;s disease in Drosophila. This paper outlines two assays that characterize both spontaneous and startle-induced locomotion deficiencies caused by rotenone.

Methods to Characterize Spontaneous and Startle-induced Locomotion in a Rotenone-induced Parkinson's Disease Model of Drosophila

Parkinson&#8217;s disease is a neurodegenerative disorder that results from the degeneration of dopaminergic neurons in the central nervous system, ...

methods-to-characterize-spontaneous-startle-induced-locomotion

Research

JoVE Journal

Neuroscience

10.0K Views.  Colby College. Parkinson’s disease is a neurodegenerative disorder that results from the degeneration of dopaminergic neurons in the central nervous system, causing locomotion defects. Rotenone models Parkinson’s disease in Drosophila. This paper outlines two assays that characterize both spontaneous and startle-induced locomotion deficiencies caused by rotenone.

Video: Methods to Characterize Spontaneous and Startle-induced Locomotion in a Rotenone-induced Parkinson's Disease Model of Drosophila

Autologous Blood Injection to Model Spontaneous Intracerebral Hemorrhage in Mice

Investigation of the pathophysiology of injury after intracerebral
hemorrhage (ICH) requires a reproducible animal model. While ICH
accounts for 10-15% of all strokes, there remains no specific
effective therapy. The autologous blood injection model in mice
involves the stereotaxic injection of arterial blood into the basal
ganglia mimicking a spontaneous hypertensive hemorrhage in man. The
response to hemorrhage can then be studied in vivo and the
neurobehavioral deficits quantified, allowing for description of the
ensuing pathology and the testing of potential therapeutic agents. The
procedure described in this protocol uses the double injection
technique to minimize risk of blood reflux up the needle track, no
anticoagulants in the pumping system, and eliminates all dead space
and expandable tubing in the system.

The autologous blood injection model of intracerebral hemorrhage in mice described in this protocol uses the double injection technique to minimize risk of blood reflux up the needle track, no anticoagulants in the pumping system, and eliminates all dead space and expandable tubing in the system.

Investigation of the pathophysiology of injury after intracerebral
hemorrhage (ICH) requires a reproducible animal model.  While ICH
accounts for 10-15% ...

Methods to Assay Drosophila Behavior

Drosophila melanogaster, the fruit fly, has been used to study molecular mechanisms of a wide range of human diseases such as cancer, cardiovascular disease and various neurological diseases1. We have optimized simple and robust behavioral assays for determining larval locomotion, adult climbing ability (RING assay), and courtship behaviors of Drosophila. These behavioral assays are widely applicable for studying the role of genetic and environmental factors on fly behavior. Larval crawling ability can be reliably used for determining early stage changes in the crawling abilities of Drosophila larvae and also for examining effect of drugs or human disease genes (in transgenic flies) on their locomotion. The larval crawling assay becomes more applicable if expression or abolition of a gene causes lethality in pupal or adult stages, as these flies do not survive to adulthood where they otherwise could be assessed. This basic assay can also be used in conjunction with bright light or stress to examine additional behavioral responses in Drosophila larvae. Courtship behavior has been widely used to investigate genetic basis of sexual behavior, and can also be used to examine activity and coordination, as well as learning and memory. Drosophila courtship behavior involves the exchange of various sensory stimuli including visual, auditory, and chemosensory signals between males and females that lead to a complex series of well characterized motor behaviors culminating in successful copulation. Traditional adult climbing assays (negative geotaxis) are tedious, labor intensive, and time consuming, with significant variation between different trials2-4. The rapid iterative negative geotaxis (RING) assay5 has many advantages over more widely employed protocols, providing a reproducible, sensitive, and high throughput approach to quantify adult locomotor and negative geotaxis behaviors. In the RING assay, several genotypes or drug treatments can be tested simultaneously using large number of animals, with the high-throughput approach making it more amenable for screening experiments.

Methods to Assay Drosophila Behavior

Drosophila melanogaster is a genetically and behaviorally tractable model system that has been used to understand the molecular and cellular basis of many important biological processes for over a century 1. Drosophila has been well exploited to gain insights into the genetic basis of fly behavior.

Drosophila melanogaster, the fruit fly, has been used to study molecular mechanisms of a wide range of human diseases such as cancer, cardiovascular ...

Multi-unit Recording Methods to Characterize Neural Activity in the Locust (Schistocerca Americana) Olfactory Circuits

Detection and interpretation of olfactory cues are critical for the survival of many organisms. Remarkably, species across phyla have strikingly similar olfactory systems suggesting that the biological approach to chemical sensing has been optimized over evolutionary time1. In the insect olfactory system, odorants are transduced by olfactory receptor neurons (ORN) in the antenna, which convert chemical stimuli into trains of action potentials. Sensory input from the ORNs is then relayed to the antennal lobe (AL; a structure analogous to the vertebrate olfactory bulb). In the AL, neural representations for odors take the form of spatiotemporal firing patterns distributed across ensembles of principal neurons (PNs; also referred to as projection neurons)2,3. The AL output is subsequently processed by Kenyon cells (KCs) in the downstream mushroom body (MB), a structure associated with olfactory memory and learning4,5. Here, we present electrophysiological recording techniques to monitor odor-evoked neural responses in these olfactory circuits.
First, we present a single sensillum recording method to study odor-evoked responses at the level of populations of ORNs6,7. We discuss the use of saline filled sharpened glass pipettes as electrodes to extracellularly monitor ORN responses. Next, we present a method to extracellularly monitor PN responses using a commercial 16-channel electrode3. A similar approach using a custom-made 8-channel twisted wire tetrode is demonstrated for Kenyon cell recordings8. We provide details of our experimental setup and present representative recording traces for each of these techniques.

Multi-unit Recording Methods to Characterize Neural Activity in the Locust Schistocerca Americana Olfactory Circuits

We demonstrate variations of the extracellular multi-unit recording technique to characterize odor-evoked responses in the first three stages of the invertebrate olfactory pathway. These techniques can easily be adapted to examine ensemble activity in other neural systems as well.

Detection and interpretation of olfactory cues are critical for the survival  of many organisms. Remarkably, species across phyla have strikingly similar ...

Determination of the Spontaneous Locomotor Activity in Drosophila melanogaster

Drosophila melanogaster has been used as an excellent model organism to study environmental and genetic manipulations that affect behavior. One such behavior is spontaneous locomotor activity. Here we describe our protocol that utilizes Drosophila population monitors and a tracking system that allows continuous monitoring of the spontaneous locomotor activity of flies for several days at a time. This method is simple, reliable, and objective and can be used to examine the effects of aging, sex, changes in caloric content of food, addition of drugs, or genetic manipulations that mimic human diseases.

Determination of the Spontaneous Locomotor Activity in Drosophila melanogaster

Drosophila melanogaster are useful in studying genetic or environmental manipulations that affect behaviors such as spontaneous locomotor activity.&#160; Here we describe a protocol that utilizes monitors with infrared beams and data analysis software to quantify spontaneous locomotor activity.&#160;

Drosophila melanogaster has been used as an excellent model organism to study environmental and genetic manipulations that affect behavior. One such ...

A Novel Method to Model Chronic Traumatic Encephalopathy in Drosophila

Chronic Traumatic Encephalopathy (CTE) is an established neurodegenerative disease that is closely associated with exposure to repetitive mild Traumatic Brain Injury (mTBI). The mechanisms responsible for its complex pathological changes remain largely elusive, despite a recent consensus to define the neuropathological criteria. Here, we describe a novel method to develop a model of CTE in Drosophila melanogaster&#160;(Drosophila&#160;)&#160;in an attempt to identify the key genes and pathways that lead to the characteristic hyperphosphorylated tau accumulation and neuronal death in the brain. Adjustable-strength impacts to inflict mild closed injury are delivered directly to the fly head, subjecting the head to rapid acceleration and deceleration. Our method eliminates the potential problems inherent with other Drosophila mTBI models (e.g.,animal death might be induced by damage to other parts of the body or to internal organs). The less labor- and cost-intensive animal care, short life span, and extensive genetic tools make the fruit fly ideal to study CTE pathogenesis and make it possible to perform large-scale, genome-wide forward genetic and pharmacological screens. We anticipate that the ongoing characterization of the model will generate important mechanistic insights on disease prevention and therapeutic approaches.

A Novel Method to Model Chronic Traumatic Encephalopathy in Drosophila

Here, we describe a new approach to inflict closed-head traumatic brain injury in Drosophila melanogaster. Our method has the advantage of directly delivering repetitive impacts with adjustable strength to the head alone. Further exploration of the invertebrate system will help to illuminate the pathogenesis of chronic traumatic encephalopathy.

Chronic Traumatic Encephalopathy (CTE) is an established neurodegenerative disease that is closely associated with exposure to repetitive mild Traumatic ...

Quantifying Spontaneous Ca2+ Fluxes and their Downstream Effects in Primary Mouse Midbrain Neurons

Parkinson&#8217;s disease (PD) is a devastating neurodegenerative disorder caused by the degeneration of dopaminergic (DA) neurons. Excessive Ca2+ influx due to the abnormal activation of glutamate receptors results in DA excitotoxicity and has been identified as an important mechanism for DA neuron loss. In this study, we isolate, dissociate, and culture midbrain neurons from the mouse ventral mesencephalon (VM) of ED14 mouse embryos. We then infect the long-term primary mouse midbrain cultures with an adeno-associated virus (AAV) expressing a genetically encoded calcium indicator, GCaMP6f under control of the human neuron-specific synapsin promoter, hSyn. Using live confocal imaging, we show that cultured mouse midbrain neurons display spontaneous Ca2+ fluxes detected by AAV-hSyn-GCaMP6f. Bath application of glutamate to midbrain cultures causes abnormal elevations in intracellular Ca2+ within neurons and this is accompanied by caspase-3 activation in DA neurons, as demonstrated by immunostaining. The techniques to identify glutamate-mediated apoptosis in primary mouse DA neurons have important applications for the high content screening of drugs that preserve DA neuron health.

Quantifying Spontaneous Ca2+ Fluxes and their Downstream Effects in Primary Mouse Midbrain Neurons

Here we present a protocol to measure in vitro Ca2+ fluxes in midbrain neurons and their downstream effects on caspase-3 using primary mouse midbrain cultures. This model can be employed to study pathophysiologic changes related to abnormal Ca2+ activity in midbrain neurons, and to screen novel therapeutics for anti-apoptotic properties.

Parkinson&#8217;s disease (PD) is a devastating neurodegenerative disorder caused by the degeneration of dopaminergic (DA) neurons. Excessive Ca2+ influx ...

Applying the RatWalker System for Gait Analysis in a Genetic Rat Model of Parkinson's Disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder caused by the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta. Gait abnormalities, including decreased arm swing, slower walking speed, and shorter steps are common in PD patients and appear early in the course of disease. Thus, the quantification of motor patterns in animal models of PD will be important for phenotypic characterization during disease course and upon therapeutic treatment. Most cases of PD are idiopathic; however, the identification of hereditary forms of PD uncovered gene mutations and variants, such as loss-of-function mutations in Pink1 and Parkin, two proteins involved in mitochondrial quality control that could be harnessed to create animal models. While mice are resistant to neurodegeneration upon loss of Pink1 and Parkin (single and combined deletion), in rats, Pink1 but not Parkin deficiency leads to nigral DA neuron loss and motor impairment. Here, we report the utility of FTIR imaging to uncover gait changes in freely walking young (2 months of age) male rats with combined loss of Pink1 and Parkin prior to the development of gross visually apparent motor abnormality as these rats age (observed at 4-6 months), characterized by hindlimb dragging as previously reported in Pink1 knockout (KO) rats.

Here we describe the RatWalker system, built by redesigning the MouseWalker apparatus to accommodate for the increased size and weight of rats. This system uses frustrated total internal reflection (FTIR), high-speed video capture, and open-access analysis software to track and quantify gait parameters.

Parkinson's disease (PD) is a progressive neurodegenerative disorder caused by the loss of dopaminergic (DA) neurons in the substantia nigra pars ...

The 6-hydroxydopamine Rat Model of Parkinson's Disease

Motor symptoms of Parkinson's disease (PD)-bradykinesia, akinesia, and tremor at rest-are consequences of the neurodegeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc) and dopaminergic striatal deficit. Animal models have been widely used to simulate human pathology in the laboratory. Rodents are the most used animal models for PD due to their ease of handling and maintenance. Moreover, the anatomy and molecular, cellular, and pharmacological mechanisms of PD are similar in rodents and humans. The infusion of the neurotoxin, 6-hydroxydopamine (6-OHDA), into a medial forebrain bundle (MFB) of rats reproduces the severe destruction of dopaminergic neurons and simulates PD symptoms. This protocol demonstrates how to perform the unilateral microinjection of 6-OHDA in the MFB in a rat model of PD and shows the motor deficits induced by 6-OHDA and predicted dopaminergic lesions through the stepping test. The 6-OHDA causes significant impairment in the number of steps performed with the contralateral forelimb.

The 6-hydroxydopamine (6-OHDA) model has been used for decades to advance the understanding of Parkinson's Disease. In this protocol, we demonstrate how to perform unilateral nigrostriatal lesions in the rat by injecting 6-OHDA in the medial forebrain bundle, assess motor deficits, and predict lesions using the stepping test.

Motor symptoms of Parkinson's disease (PD)-bradykinesia, akinesia, and tremor at rest-are consequences of the neurodegeneration of dopaminergic neurons in ...

Induction and Assessment of Levodopa-induced Dyskinesias in a Rat Model of Parkinson's Disease

Levodopa (L-DOPA) remains the gold-standard therapy used to treat Parkinson&#39;s disease (PD) motor symptoms. However, unwanted involuntary movements known as L-DOPA-induced dyskinesias (LIDs) develop with prolonged use of this dopamine precursor.&#160;It is estimated that the incidence of LIDs escalates to approximately 90% of individuals with PD within 10&#8211;15 years of treatment. Understanding the mechanisms of this malady and developing both novel and effective anti-dyskinesia treatments requires consistent and accurate modeling for pre-clinical testing of therapeutic interventions. A detailed method for reliable induction and comprehensive rating of LIDs following 6-OHDA-induced nigral lesioning in a rat model of PD is presented here. Dependable LID assessment in rats provides a powerful tool that can be readily utilized across laboratories to test emerging therapies focused on reducing or eliminating this common treatment-induced burden for individuals with PD.

This article describes methods to induce and evaluate levodopa-induced dyskinesias in a rat model of Parkinson&#39;s disease. The protocol offers detailed information regarding the intensity and frequency of a range of dyskinetic behaviors, both dystonic and hyperkinetic, providing a reliable tool to test treatments targeting this unmet medical need.

Levodopa (L-DOPA) remains the gold-standard therapy used to treat Parkinson&#39;s disease (PD) motor symptoms. However, unwanted involuntary movements ...

Locomotor Assessment of 6-Hydroxydopamine-induced Adult Zebrafish-based Parkinson's Disease Model

The limitations of current treatments in delaying dopaminergic neuronal loss in Parkinson&#39;s disease (PD) raise the need for alternative therapies that can restore these neurons. Much effort is currently directed toward a better understanding of neuroregeneration using preclinical in vivo models. This regenerative capability for self-repair is, however, inefficient in mammals. Non-mammalian animals like zebrafish have thus emerged as an excellent neuroregenerative model due to its capability to continuously self-renew and have a close brain homology to humans. As part of the effort in elucidating cellular events involved in neuroregeneration in vivo, we have established the 6-hydroxydopamine (6-OHDA)-induced adult zebrafish-based PD model. This was achieved through the optimized intracerebroventricular (ICV) microinjection of 99.96&#160;mM 6-OHDA to specifically ablate dopaminergic neurons (DpN) in the ventral diencephalon (Dn) of zebrafish brain. Immunofluorescence indicated more than 85% of DpN ablation at day three postlesion and full restoration of DpN at lesioned site 30 days postlesion. The present study determined the impairment and subsequent recovery of zebrafish swimming behavior following lesion by using the open field test through which two parameters, distance traveled (cm) and mean speed (cm/s), were quantified. The locomotion was assessed by analyzing the recordings of individual fish of each group (n = 6) using video tracking software. The findings showed a significant (p &#60; 0.0001) reduction in speed (cm/s) and distance traveled (cm) of lesioned zebrafish 3 days postlesion when compared to sham. The lesioned zebrafish exhibited full recovery of swimming behavior 30 days postlesion. The present findings suggest that 6-OHDA lesioned adult zebrafish is an excellent model with reproducible quality to facilitate the study of neuroregeneration in PD. Future studies on the mechanisms underlying neuroregeneration as well as intrinsic and extrinsic factors that modulate the process may provide important insight into new cell replacement treatment strategies against PD.

The present protocol describes the intracerebroventricular (ICV) injection of adult zebrafish with neurotoxic 6-hydroxydopamine (6-OHDA) at the ventral diencephalon (Dn) and the assessment of the impairment and subsequent recovery of swimming behavior postlesion by using the open tank test, which is accompanied by analysis using a video tracking software.

The limitations of current treatments in delaying dopaminergic neuronal loss in Parkinson&#39;s disease (PD) raise the need for alternative therapies that ...