Name: pentylenetetrazole-induced kindling mouse model
Uploaded: 2018-06-12T12:30:00
Description: Watch this Scientific Journal Video about Pentylenetetrazole-Induced Kindling Mouse Model at JoVE.com

This work was partly supported by JSPS KAKENHI grant numbers 24700349, 24659093, 25293239, JP18H02536, and 17K07086, MEXT KAKENHI grant numbers 25110737 and 23110525, AMED Grant Number JP18ek0109311, and the SENSHIN Medical Research Foundation and the Japan Epilepsy Research Foundation.

All experimental procedures were approved by the Animal Care and Use Committee of the Tokyo Metropolitan Institute of Medical Science. Postnatal 8 - 16-week-old mice are recommended. Any inbred strain is acceptable for the experiment. C57BL/6 mice are more resistant to PTZ, whereas BALB/c and Swiss albino mice are more sensitive to PTZ. C57BL/6 were used in this study. Vulnerability to PTZ also depends on the age of the mouse. Compared to younger mice, older mice are more refractory to PTZ35. The ...

Here, we present a widely accessible protocol for the establishment of a pharmacological animal model of epilepsy. PTZ-mediated chemical kindling has a long history and is a commonly accepted model for the study of the histopathology and cellular pathology of epilepsy41. The chemical kindling model of epilepsy has been reviewed previously by Suzdak and Jansen, 199542. Pharmacological seizure induction, especially with PTZ, is an easy and simple method for evoking severe sei...

Epilepsy is a chronic neurological disorder that is characterized by recurrent seizures and affects approximately 1% of people. The underlying mechanisms of epileptogenesis and seizure generation in epilepsy patients cannot be fully clarified in clinical studies. Therefore, an appropriate animal model is required for the study of epilepsy1.
A variety of animal models of epilepsy have been used to investigate the physiology of epilepsy and to identify anti-epileptic drugs2,3. Among these models, pharmacological seizure induction is a common method used to generate an animal model for the investigation of the pathology of epilepsy4. This method is inexpensive and simple. Electrode-mediated kindling is also a commonly used method, but the costs of this procedure are higher, and the method requires surgical and electrical skills to induce repetitive seizures5.
Pharmacological induction is also advantageous because the timing and number of seizures are easily controlled. Genetic mouse models that exhibit spontaneous seizures are also used in the study of epilepsy. However, predicting when and how often the seizures arise in these genetic models may be impossible6. A monitoring system is required to observe the epileptic behavior of genetically modified mice6.
Kainic acid, pilocarpine and pentylenetetrazole (PTZ) are widely used as seizure-inducing drugs7. Kainic acid is an agonist for glutamate receptors, and pilocarpine activates cholinergic receptors. PTZ is a gamma aminobutyric acid (GABA)-A receptor antagonist8. PTZ suppresses the function of inhibitory synapses, leading to increased neuronal activity. This regulation causes generalized seizures in animals9. A single injection of kainic acid and pilocarpine can induce acute seizures, especially status epilepticus (SE)10,11 and kainic acid- or pilocarpine-mediated SE promotes chronic spontaneous and recurrent seizures12,13. Electroencephalographic (EEG) recordings and behavior analysis have indicated that spontaneous recurrent seizures are observed a month after a single injection12,13. A single injection of a convulsive dose of PTZ also induces acute seizure. However, chronic spontaneous seizures after a single injection of PTZ are difficult to promote. Chronic administration of PTZ is required to induce repetitive seizures14. In either method, the generation of repetitive seizures is able to induce a pathology more similar to that of human epilepsy than the generation of acute seizures. In the case of PTZ, each injection evokes a seizure, and seizure severity becomes more severe in a stepwise manner with each injection. Finally, a single low-dose PTZ injection induces a severe tonic-clonic seizure. In this phase, each injection evokes severe seizures. In addition, the seizure latency and duration also change over the course of the injections. The latency to tonic seizure often becomes shorter in the latter phase of kindling15. Furthermore, seizure aggravation is accompanied by a prolonged seizure duration16. Investigating the molecular mechanism regulating the seizure severity, latency, and duration is useful for screening anti-epileptic drugs17,18,19.
Seizures are commonly induced by a single systemic administration of PTZ, and the recovery is very fast, within 30 min4,5. Thus, the number of seizures is more controllable in the PTZ-kindling model. However, EEG monitoring has indicated that generalized spikes may be seen up to 12 h after PTZ-mediated seizure20. Therefore, animals should preferably remain under observation for 24 h after the myoclonic or tonic seizure21 for more precise analysis of the kindling mechanisms.
The administration of anti-epileptic drugs, such as ethosuximide, valproate, phenobarbital, vigabatrin, and retigabine3, before or after PTZ injection mitigates the aggravation of the seizure severity3,22,23. Similarly, knockout mice that lack genes involved in seizure exacerbation, such as matrix metalloproteinase-924, FGF-2225 and neuritin26, have been shown to exhibit reduced seizure severity after multiple PTZ injections. In addition, observing histopathological alterations after epileptic seizures is possible with this method. In patients with temporal lobe epilepsy, there are typical histological changes in the brain, such as mossy fiber sprouting27,28, abnormal granule neuron migration29, astrogliosis30, neuronal cell death in the hippocampus31,32, and hippocampal sclerosis33. Similar changes are observed in epileptic model animals. Among the available methods, PTZ-mediated chemical kindling is a good, reproducible and inexpensive method to produce an animal model of epilepsy. In a pilocarpine-mediated SE model, seizure control is difficult and many mice die or fail to develop SE34. In contrast, mortality and seizure severity are more controllable in the PTZ model. Additionally, PTZ is less expensive than kainic acid, and skills in mouse brain surgery are not required for drug administration.

<table>
	<tbody>
		<tr>
			<td>Pentylenetetrazole</td>
			<td>Sigma-Aldrich</td>
			<td>P6500</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium chloride</td>
			<td>MANAC</td>
			<td>7647-14-5</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse</td>
			<td>CLEA Japan</td>
			<td></td>
			<td>C57Bl/6NJcl, postnatal 8 week, male</td>
		</tr>
		<tr>
			<td>Syringe (1mL)</td>
			<td>Terumo</td>
			<td>SS-01T</td>
			<td></td>
		</tr>
		<tr>
			<td>Needle(27G x 3/4&#34;) (0.40 x 19 mm)</td>
			<td>Terumo</td>
			<td>NN-2719S</td>
			<td></td>
		</tr>
		<tr>
			<td>Weighing scale</td>
			<td>Mettler</td>
			<td>PE2000</td>
			<td>This item is a discontinued product. Almost equivalent to FX-2000i with FXi-12-JA from A&#38;D company.</td>
		</tr>
		<tr>
			<td>Paraformaldehyde</td>
			<td>Sigma-Aldrich</td>
			<td>P6148</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium hydroxide</td>
			<td>nacalai tesque</td>
			<td>31511-05</td>
			<td></td>
		</tr>
		<tr>
			<td>Peristatic pump</td>
			<td>ATTO</td>
			<td>SJ1211</td>
			<td></td>
		</tr>
		<tr>
			<td>Sucrose</td>
			<td>nacalai tesque</td>
			<td>30404-45</td>
			<td></td>
		</tr>
		<tr>
			<td>Microtome</td>
			<td>Yamato</td>
			<td>REM-700</td>
			<td>This item is a discontinued product. Almost equivalent to REM-710</td>
		</tr>
		<tr>
			<td>Microtome blade</td>
			<td>Feather</td>
			<td>S35</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sigma-Aldrich</td>
			<td>X-100</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-synaptoporin antibody</td>
			<td>Synaptic systems</td>
			<td>102 002</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-ZnT3 antibody</td>
			<td>Synaptic systems</td>
			<td>197 002</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-doublecortin</td>
			<td>Santa Cruz</td>
			<td>sc-8066</td>
			<td>This item is a discontinued product. We did not test equivalent product (sc-271390).</td>
		</tr>
		<tr>
			<td>Contextual fear discrimination test apparatus</td>
			<td>O&#39;hara</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Three chamber test apparatus</td>
			<td>Muromachi</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

pentylenetetrazole-induced kindling mouse model

Pentylenetetrazole (PTZ) is a GABA-A receptor antagonist. An intraperitoneal injection of PTZ into an animal induces an acute, severe seizure at a high dose, whereas sequential injections of a subconvulsive dose have been used for the development of chemical kindling, an epilepsy model. A single low-dose injection of PTZ induces a mild seizure without convulsion. However, repetitive low-dose injections of PTZ decrease the threshold to evoke a convulsive seizure. Finally, continuous low-dose administration of PTZ induces a severe tonic-clonic seizure. This method is simple and widely applicable to investigate the pathophysiology of epilepsy, which is defined as a chronic disease that involves repetitive seizures. This chemical kindling protocol causes repetitive seizures in animals. With this method, vulnerability to PTZ-mediated seizures or the degree of aggravation of epileptic seizures was estimated. These advantages have led to the use of this method for screening anti-epileptic drugs and epilepsy-related genes. In addition, this method has been used to investigate neuronal damage after epileptic seizures because the histological changes observed in the brains of epileptic patients also appear in the brains of chemical-kindled animals. Thus, this protocol is useful for conveniently producing animal models of epilepsy.

Repetitive injection of PTZ induces an increase in seizure severity. Six C57BL/6 mice were treated with PTZ, and another 6 mice were treated with saline as a control group. The PTZ dose was 35 mg/kg, and 10 injections were administered. The seizure score gradually increased with PTZ injections, whereas no seizures or abnormal behaviors were evoked by saline injections (Figure 2). ANOVA followed by Bonferroni test showed a significant difference between the PT...

Watch this Scientific Journal Video about Pentylenetetrazole-Induced Kindling Mouse Model at JoVE.com

Pentylenetetrazole-Induced Kindling Mouse Model

This protocol describes a method of chemical kindling with pentylenetetrazole and provides a mouse model of epilepsy. This protocol can also be used to investigate vulnerability to seizure induction and pathogenesis after epileptic seizures in mice.

Pentylenetetrazole (PTZ) is a GABA-A receptor antagonist. An intraperitoneal injection of PTZ into an animal induces an acute, severe seizure at a high ...

This method can help the deep analysis of epilepsy. Seizure will induce histological changes in the brain which may be involved in the neuropsychiatric developmental disorders. The main advantage with this technique is that self-conversive dose of PTZ can induce controllable seizures better than the other current methods.Begin preparing the injection by dissolving 2 milligrams per milliliter PTZ in sterile 0.9 percent sodium chloride. Weigh the animal, then place it in an observation chamber for a 3-minute habituation period. Next, inject PTZ interperitoneally with a 1 milliliter syringe attached to a 27 gauge needle into the left or right quadrant of the abdomen of the animal.Finally, observe the animal after PTZ injection for abnormal behavior. Obtain at least two two-to-six month old 129 SV mice who are of the same sex as the subject mice to be the stranger mouse. Each stranger mouse must be kept separately.For each training session, leave the mouse in the cage for habituation for 15 minutes. Clean the entire apparatus in both cages by wiping the surface with 70%ethanol. Then, place the empty cages in the two side chambers of the three-chamber apparatus and open the doors between the chambers.To habituate the subject mouse, place the subject mouse in the center chamber and allow the mouse to move freely throughout the apparatus until the mouse has investigated both cages, plus an additional five minutes. After the animal moves into the center chamber, close the doors and let the mouse move freely in the center chamber for five minutes. During this period, put one of the 129 SV mice in a cage to habituate to the cage.Immediately after the habituation period of the subject mouse, place the cage containing the 129 SV mouse, termed the Stranger One cage, in one of the side chambers and place the empty cage, termed the Object cage, in the other side chamber. Open the door and monitor the behavior of the subject mouse. Allow the subject mouse to move freely for 10 minutes and record four behavioral parameters.Number one, the time spent in each chamber, the Stranger One chamber, the Object chamber and the center chamber. Number two, time spent investigating each cage, the Stranger One cage and the Object cage. Number three, the number of entrances into each chamber and Number four, the total distance traveled.After the mouse moves into the center chamber, close the doors. After wiping the cages, begin the social novelty analysis by placing another 129 SV mouse in one of the cages, termed the Stranger Two cage, and place the Stranger Two cage in one of the chambers. Place the Stranger One mouse in the other cage, termed the Stranger One cage and place the Stranger One cage in the other chamber.Finally, open the door and monitor the behavior of the subject mouse. Allow the subject mouse to move freely for 10 minutes and measure the same behavioral parameters described for the sociality analysis. Begin by placing a mouse in a conditioning apparatus with specific conditions.For example, a square apparatus with clear plexiglass walls, a metal grid floor, an ethanol odor, 100 lux brightness and 65 decibel background white noise. Condition the mouse by foot shock with pseudo-random timing of a 0.1 milliamp electrical shocks for two seconds three times over the course of five minutes. Then, return the mouse to the home cage after conditioning.The day after conditioning, perform a memory assessment by placing the mouse into the same apparatus as the shock condition and measuring the freezing time over the course of five minutes. Later the same day, place the mouse in a novel apparatus and measure the freezing time during a five-minute assessment. Finally, compare the freezing time between the same condition and novel condition.Results indicated that the seizure score gradually increased with PTZ injections, whereas no seizures or abnormal behaviors were evoked by saline injections. Further, repetitive seizure promoted aberrant axonal branch formation or mossy fiber sprouting and abnormal migration of granule cells in the hippocampus. PTZ-treated mice showed normal sociality.Mice spent more time in the Stranger One chamber than in the Object chamber and investigated the Stranger One cage more than they investigated the Object cage. PTZ-treated mice showed abnormal social novelty, indicative of impaired social memory. PTZ-treated mice also showed impaired memory in the contextual fear test.Following this procedure, other methods like Morris water maze or the other memory tests can be performed to answer the additional questions about the impaired memory ability affected by epileptic seizure. After its development, this technique paves the way for the researchers in the field of epilepsy to explore as a mechanism of seizure-induced neuropsychiatric developmental disorders by using model animals.

pentylenetetrazole-induced-kindling-mouse-model

Research

JoVE Journal

Neuroscience

Multiple-mouse Neuroanatomical Magnetic Resonance Imaging

The field of mouse phenotyping with magnetic resonance imaging (MRI) is rapidly growing, motivated by the need for improved tools for characterizing and evaluating mouse models of human disease. MRI is an excellent modality for investigating genetically altered animals. It is capable of whole brain coverage, can be used in vivo, and provides multiple contrast mechanisms for investigating different aspects of neuranatomy and physiology. The advent of high-field scanners along with the ability to scan multiple mice simultaneously allows for rapid phenotyping of novel mutations.
Effective mouse MRI studies require attention to many aspects of experiment design. In this article, we will describe general methods to acquire quality images for mouse phenotyping using a system that images mice concurrently in shielded transmit/receive radio frequency (RF) coils in a common magnet (Bock et al., 2003). We focus particularly on anatomical phenotyping, an important and accessible application that has shown a high potential for impact in many mouse models at our imaging centre. Before we can provide the detailed steps to acquire such images, there are important practical considerations for both in vivo brain imaging (Dazai et al., 2004) and ex vivo brain imaging (Spring et al., 2007) that should be noted. These are discussed below.

Magnetic resonance imaging (MRI) has become an increasingly popular tool for examining the phenotype of genetically altered mice. This article illustrates the methods necessary to achieve high-throughput phenotyping of genetically altered mice using multiple-mouse MRI.

The field of mouse phenotyping with magnetic resonance imaging (MRI) is rapidly growing, motivated by the need for improved tools for characterizing and ...

Detection of Neuritic Plaques in Alzheimer's Disease Mouse Model

Alzheimer's disease (AD) is the most common neurodegenerative disorder leading to dementia. Neuritic plaque formation is one of the pathological hallmarks of Alzheimer's disease. The central component of neuritic plaques is a small filamentous protein called amyloid &beta; protein (A&beta;)1, which is derived from sequential proteolytic cleavage of the beta-amyloid precursor protein (APP) by &beta;-secretase and &gamma;-secretase. The amyloid hypothesis entails that A&gamma;-containing plaques as the underlying toxic mechanism in AD pathology2. The postmortem analysis of the presence of neuritic plaque confirms the diagnosis of AD. To further our understanding of A&gamma; neurobiology in AD pathogenesis, various mouse strains expressing AD-related mutations in the human APP genes were generated. Depending on the severity of the disease, these mice will develop neuritic plaques at different ages. These mice serve as invaluable tools for studying the pathogenesis and drug development that could affect the APP processing pathway and neuritic plaque formation. In this protocol, we employ an immunohistochemical method for specific detection of neuritic plaques in AD model mice. We will specifically discuss the preparation from extracting the half brain, paraformaldehyde fixation, cryosectioning, and two methods to detect neurotic plaques in AD transgenic mice: immunohistochemical detection using the ABC and DAB method and fluorescent detection using thiofalvin S staining method.

One of the pathological characteristics of AD is the formation of Amyloid &#x03B2; protein positive neuritic plaques. In this protocol we describe two methods to detect neuritic plaques in transgenic AD model mice: immunohistochemical detection using the ABC and DAB method and fluorescent detection using thioflavin S staining method.

Alzheimer's disease (AD) is the most common neurodegenerative disorder leading to dementia. Neuritic plaque formation is one of the pathological hallmarks ...

Methods for Intravenous Self Administration in a Mouse Model

Animal models have been developed to study the reinforcing effects of drugs, including the intravenous self-administration (IVSA) paradigm. The advantages of using an IVSA paradigm to study the reinforcing properties of drugs of abuse such as cocaine include the fact that the drug is self-administered instead of experimenter-administered, the schedule of reinforcement can be altered, and accurate measurement of the quantities of drug consumed as well as the timing and pattern of IV injections can be obtained. Furthermore, the intravenous route of administration avoids potential confounds related to first pass metabolism or taste, and produces rapid increases in blood and brain drug levels. As outlined in this video, intravenous self-administration can be obtained without prior food restriction or prior drug training following careful catheter placement during surgery and meticulous daily catheter flushing and maintenance. Experimental procedures outlined in this paper include a description of animal housing and acclimation methods, operant training using sweetened milk solutions, and catheter implantation surgery.

The intravenous self-administration (IVSA) paradigm is considered to be the gold standard in examining the reinforcing properties of drugs of abuse in rodents. This manuscript outlines the experimental procedures and surgical techniques necessary to obtain reliable IVSA data. In particular, meticulous catheter implantation and maintenance are highlighted.

Animal models have been developed to study the reinforcing effects of drugs, including the intravenous self-administration (IVSA) paradigm. The advantages ...

Trypsin Digest Protocol to Analyze the Retinal Vasculature of a Mouse Model

Trypsin digest is the gold standard method to analyze the retinal vasculature 1-5. It allows visualization of the entire network of complex three-dimensional retinal blood vessels and capillaries by creating a two-dimensional flat-mount of the interconnected vascular channels after digestion of the non-vascular components of the retina. This allows one to study various pathologic vascular changes, such as microaneurysms, capillary degeneration, and abnormal endothelial to pericyte ratios. However, the method is technically challenging, especially in mice, which have become the most widely available animal model to study the retina because of the ease of genetic manipulations 6,7. In the mouse eye, it is particularly difficult to completely remove the non-vascular components while maintaining the overall architecture of the retinal blood vessels. To date, there is a dearth of literature that describes the trypsin digest technique in detail in the mouse. This manuscript provides a detailed step-by-step methodology of the trypsin digest in mouse retina, while also providing tips on troubleshooting difficult steps.

Trypsin digest is one of the most commonly used methods to analyze retinal vasculature. This manuscript describes the method in detail, including key alterations to optimize the technique and remove the non-vascular tissue while preserving the overall architecture of the vessels.

Trypsin digest is the gold standard method to analyze the retinal vasculature 1-5. It allows visualization of the entire network of complex ...

The Corneal Micropocket Assay: A Model of Angiogenesis in the Mouse Eye

The mouse corneal micropocket assay is a robust and quantitative in vivo assay for evaluating angiogenesis. By using standardized slow-release pellets containing specific growth factors that trigger blood vessel growth throughout the naturally avascular cornea, angiogenesis can be measured and quantified. In this assay the angiogenic response is generated over the course of several days, depending on the type and dose of growth factor used. The induction of neovascularization is commonly triggered by either basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF). By combining these growth factors with sucralfate and hydron (poly-HEMA (poly(2-hydroxyethyl methacrylate))) and casting the mixture into pellets, they can be surgically implanted in the mouse eye. These uniform pellets slowly-release the growth factors over five or six days (bFGF or VEGF respectively) enabling sufficient angiogenic response required for vessel area quantification using a slit lamp. This assay can be used for different applications, including the evaluation of angiogenic modulator drugs or treatments as well as comparison between different genetic backgrounds affecting angiogenesis. A skilled investigator after practicing this assay can implant a pellet in less than 5 min per eye.

The protocol describes the corneal micropocket assay as developed in mice.

The mouse corneal micropocket assay is a robust and quantitative in vivo assay for evaluating angiogenesis. By using standardized slow-release pellets ...

Measuring Progressive Neurological Disability in a Mouse Model of Multiple Sclerosis

After intracerebral infection with the Theiler's Murine Encephalomyelitis Virus (TMEV), susceptible SJL mice develop a chronic-progressive demyelinating disease, with clinical features similar to the progressive forms of multiple sclerosis (MS). The mice show progressive disability with loss of motor and sensory functions, which can be assessed with multiple apparatuses and protocols. Among them, the Rotarod performance test is a very common behavioral test, its advantage being that it provides objective measurements, but it is often used assuming that it is straightforward and simple. In contrast to visual scoring systems used in some models of MS, which are highly subjective, the Rotarod test generates an objective, measurable, continuous variable (i.e., length of time), allowing almost perfect inter-rater concordances. However, inter-laboratory reliability is only achieved if the various testing parameters are replicated. In this manuscript, recommendations of specific testing parameters, such as size, speed, and acceleration of the rod; amount of training given to the animals; and data processing, are presented for the Rotarod test.

An optimized testing protocol is presented in this paper for the Rotarod performance test, used for measuring progressive neurological disability in TMEV-infected mice.

After intracerebral infection with the Theiler's Murine Encephalomyelitis Virus (TMEV), susceptible SJL mice develop a chronic-progressive demyelinating ...

Neurobehavioral Assessments in a Mouse Model of Neonatal Hypoxic-ischemic Brain Injury

We performed unilateral carotid artery occlusion on CD-1 mice to create a neonatal hypoxic-ischemic (HI) model and investigated the effects of neonatal HI brain injury by studying neurobehavioral functions in these mice compared to non-operated (i.e., normal) mice. During the study, Rice-Vannucci&#39;s method was used to induce neonatal HI brain damage in postnatal day 7-10 (P7-10) mice. The HI operation was performed on the pups by unilateral carotid artery ligation and exposure to hypoxia (8% O2 and 92% N2 for 90 min). One week after the operation, the damaged brains were evaluated with the naked eye through the semi-transparent skull and were categorized into subgroups based on the absence (&#34;no cortical injury&#34; group) or presence (&#34;cortical injury&#34; group) of cortical injury, such as a lesion in the right hemisphere. On week 6, the following neurobehavioral tests were performed to evaluate the cognitive and motor functions: passive avoidance task (PAT), ladder walking test, and grip strength test. These behavioral tests are helpful in determining the effects of neonatal HI brain injury and are used in other mouse models of neurodegenerative diseases. In this study, neonatal HI brain injury mice showed motor deficits that corresponded to right hemisphere damage. The behavioral test results are relevant to the deficits observed in human neonatal HI patients, such as cerebral palsy or neonatal stroke patients. In this study, a mouse model of neonatal HI brain injury was established and showed different degrees of motor deficits and cognitive impairment compared to non-operated mice. This work provides basic information on the HI mouse model. MRI images demonstrate the different phenotypes, separated according to the severity of brain damage by motor and cognitive tests.

We performed unilateral carotid artery occlusion on postnatal day 7-10 CD-1 mouse pups to create a neonatal hypoxic-ischemic (HI) model and investigated the effects of HI brain injury. We studied neurobehavioral functions in these mice compared to non-operated normal mice.

We performed unilateral carotid artery occlusion on CD-1 mice to create a neonatal hypoxic-ischemic (HI) model and investigated the effects of neonatal HI ...

In Vivo Multimodal Imaging and Analysis of Mouse Laser-Induced Choroidal Neovascularization Model

Laser-induced choroidal neovascularization (CNV) is a well-established model to mimic the wet form of age-related macular degeneration (AMD). In this protocol, we aim to guide the reader not simply through the technical considerations of generating laser-induced lesions to trigger neovascular processes, but rather focus on the powerful information that can be obtained from multimodal longitudinal in vivo imaging throughout the follow-up period.
The laser-induced mouse CNV model was generated by a diode laser administration. Multimodal in vivo imaging techniques were used to monitor CNV induction, progression and regression. First, spectral domain optical coherence tomography (SD-OCT) was performed immediately after the lasering to verify a break of Bruch&#39;s membrane. Subsequent in vivo imaging using fluorescein angiography (FA) confirmed successful damage of Bruch&#39;s membrane from serial images acquired at the choroidal level. Longitudinal follow-up of CNV proliferation and regression on days 5, 10, and 14 after the lasering was performed using both SD-OCT and FA. Simple and reliable grading of leaky CNV leasions from FA images is&#160;presented. Automated segmentation for measurement of total retinal thickness, combined with manual caliber application for measurement of retinal thickness at CNV sites, allow unbiased evaluation of the presence of edema. Finally, histological verification of CNV is performed using isolectin GS-IB4 staining on choroidal flatmounts. The staining is thresholded, and the isolectin-positive area is calculated with ImageJ.
This protocol is especially useful in therapeutics studies requiring high-throughput-like screening of CNV pathology as it allows fast, multimodal, and reliable classification of CNV pathology and retinal edema. In addition, high resolution SD-OCT enables the recording of other pathological hallmarks, such as the accumulation of subretinal or intraretinal fluid. However, this method does not provide a possibility to automate CNV volume analysis from SD-OCT images, which has to be performed manually.

In Vivo Multimodal Imaging and Analysis of Mouse Laser-Induced Choroidal Neovascularization Model

Here, we present the usefulness of longitudinal in vivo imaging in the follow-up of morphological changes of laser-induced choroidal neovascularization in mice.

Laser-induced choroidal neovascularization (CNV) is a well-established model to mimic the wet form of age-related macular degeneration (AMD). In this ...

The Mouse Hindbrain As a Model for Studying Embryonic Neurogenesis

The mouse embryo forebrain is the most commonly employed system for studying mammalian neurogenesis during development. However, the highly folded forebrain neuroepithelium is not amenable to wholemount analysis to examine organ-wide neurogenesis patterns. Moreover, defining the mechanisms of forebrain neurogenesis is not necessarily predictive of neurogenesis in other parts of the brain; for example, due to the presence of forebrain-specific progenitor subtypes. The mouse hindbrain provides an alternative model for studying embryonic neurogenesis that is amenable to wholemount analysis, as well as tissue sections to observe the spatiotemporal distribution and behavior of neural progenitors. Moreover, it is easily dissected for other downstream applications, such as cell isolation or molecular biology analysis. As the mouse hindbrain can be readily analyzed in the vast number of cell lineage reporter and mutant mouse strains that have become available, it offers a powerful model for studying the cellular and molecular mechanisms of developmental neurogenesis in a mammalian organism. Here, we present a simple and quick method to use the mouse embryo hindbrain for analyzing mammalian neural progenitor cell (NPC) behavior in wholemount preparations and tissue sections.

This article demonstrates how the mouse embryonic hindbrain can be used as a model for studying developmental neurogenesis in both whole organ and tissue section preparations.

The mouse embryo forebrain is the most commonly employed system for studying mammalian neurogenesis during development. However, the highly folded ...

Preparation and Implantation of Electrodes for Electrically Kindling VGAT-Cre Mice to Generate a Model for Temporal Lobe Epilepsy

It was discovered that electrical kindling of VGAT-Cre mice led to the spontaneous motor and electrographic seizures. A recent paper focused on how unique VGAT-Cre mice were used in developing spontaneous recurring seizures (SRS) after kindling and a likely mechanism - insertion of Cre into the VGAT gene - disrupted its expression and reduced GABAergic tone. The present study extends these observations to a larger cohort of mice, focusing on key issues such as how long the SRS continues after kindling and the effect of the animal's sex and age. This report describes the protocols for the following key steps: making headsets with hippocampal depth electrodes for electrical stimulation and for reading the electroencephalogram; surgery to affix the headset securely on the mouse's skull so that it does not fall off; and key details of the electrical kindling protocol such as duration of the pulse, frequency of train, duration of train, and amount of current injected. The kindling protocol is robust in that it reliably leads to epilepsy in most VGAT-Cre mice, providing a new model to test for novel antiepileptogenic drugs.

This report describes the methods to generate a model of temporal lobe epilepsy based on the electrical kindling of transgenic VGAT-Cre mice. Kindled VGAT-Cre mice may be useful in determining what causes epilepsy and for screening novel therapies.

It was discovered that electrical kindling of VGAT-Cre mice led to the spontaneous motor and electrographic seizures. A recent paper focused on how unique ...