Diese Forschung wurde teilweise durch ein NSF EPSCoR Research Infrastructure Stipendium an die Clemson University (1632881) unterstützt. Darüber hinaus wurde diese Forschung teilweise vom Civitan International Research Center, Birmingham, AL unterstützt. Die Autoren danken der Nutzung der Dienste und Einrichtungen der University of Alabama in Birmingham Small Animal Imaging Shared Facility Grant [NIH P30 CA013148]. Die Autoren würdigen Rajiv Chopra für seine Unterstützung und Anleitung.

Die Autoren haben nichts zu verraten.

Hier beschrieben wir einen Benchtop-Ansatz zur mikrobubbleunterstützten FUS BBB-Öffnung mit alternativen Ansätzen, einschließlich zweier verschiedener Messumformer und Methoden für intrakranielles Targeting mit und ohne MRT-Führung. Um die MRT-geführte FUS BBB-Öffnung im Labor zu etablieren, besteht derzeit die Möglichkeit, hervorragende gebrauchsfertige Geräte zu erwerben, die hochstandardisierte und reproduzierbare Ergebnisse mit benutzerfreundlichen Schnittstellen liefern. Viele Labore sind jedoch nicht auf ...

Trotz der vielen Entdeckungen in der grundlegenden Neurowissenschaft, die Anzahl der neu auftretenden Behandlungen für neuroentwicklungs- und neurodegenerative Erkrankungen bleibt relativ begrenzt1,2. Ein tieferes Verständnis der Gene, Moleküle und zellulären Schaltkreise, die an neurologischen Störungen beteiligt sind, hat vielversprechende Behandlungen vorgeschlagen, die beim Menschen mit aktuellen Techniken nicht realisierbar sind3. Effektive Behandlungen sind oft durch die Notwendigkeit begrenzt, gehirndurchdringlich und standortspezifisch4,5,6,7,8. Die bestehenden Methoden der lokalisierten Medikamentenabgabe in bestimmte Hirnregionen (z. B. Die Abgabe per Injektion oder Kanüle) sind jedoch invasiv und erfordern eine Öffnung im Schädel9. Die Invasivität dieser Operation verhindert die routinemäßige Verwendung der lokalisierten Lieferung in das menschliche Gehirn. Darüber hinaus sind Gewebeschäden und die daraus resultierenden Entzündungsreaktionen allgegenwärtige Konfounds für grundlegende und präklinische Studien, die auf intracerebrale Injektion10angewiesen sind. Die Fähigkeit, nicht-invasiv Agenten über die Blut-Hirn-Schranke (BBB) zu liefern und sie auf bestimmte Hirnregionen zu zielen, könnte einen enormen Einfluss auf die Behandlung von neurologischen Störungen haben und gleichzeitig ein leistungsfähiges Prüfwerkzeug für die präklinische Forschung bieten.
Eine Methode des gezielten Transports über die BBB mit minimalen Gewebeschäden ist transkraniell fokussierter Ultraschall (FUS) zusammen mit Mikroblasen, um die BBB11,12,13,14,15,16fokal und vorübergehend zu öffnen. FUS BBB Eröffnung hat in jüngster Zeit Aufmerksamkeit für die Behandlung von neurodegenerativen Erkrankungen, Schlaganfall und Gliom durch die Lokalisierung von Therapeutika auf Hirnregionen wie neurotrophe Faktoren17,18,19, Gentherapien20,21,22, Antikörper23, Neurotransmitter24, und Nanopartikel25,26,27,28,29. Mit seinem breiten Anwendungsspektrum und seiner nichtinvasiven Natur30,31ist die FUS BBB Öffnung eine ideale Alternative zu routinemäßigen stereotaxic intrakraniellen Injektionen. Darüber hinaus können aufgrund seiner aktuellen Anwendung beim Menschen30,32, präklinische Untersuchungen mit dieser Technik als hochgradig translational angesehen werden. Die Eröffnung der FUS BBB ist jedoch aufgrund mangelnder Zugänglichkeit noch keine weit verbreitete Technik in der Grundlagenforschung und präklinischen Forschung. Daher bieten wir ein detailliertes Protokoll für einen Benchtop-Ansatz zur Eröffnung von FUS BBB als Ausgangspunkt für Labore, die an der Etablierung dieser Technik interessiert sind.
Diese Studien wurden entweder mit einem hochleistungsluftgestützten FUS-spezifischen Ultraschallwandler oder einem mit geringer Leistung gedämpften fokussierten Ultraschall-Immerauchwandler durchgeführt. Die Messumformer wurden von einem HF-Leistungsverstärker für reaktive Lasten und einem Standard-Tischfunktionsgenerator angetrieben. Details zu diesen Artikeln finden Sie in der Tabelle der Materialien.

<table border="0" cellpadding="0" cellspacing="0" style="width:1437px;" width="1437">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Bubble shaker</td>
			<td style="width:240px;">Lantheus Medical Imaging</td>
			<td style="width:197px;">VMIX</td>
			<td style="width:729px;">VIALMIX, actiation device used to activate Definity microbubbles</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Catheter plug/ Injection cap</td>
			<td>SAI infusion technologies</td>
			<td>Part Number: IC</td>
			<td style="width:729px;">Catheter plug/ Injection cap</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Evans blue dye</td>
			<td style="width:240px;">Sigma</td>
			<td style="width:197px;">E2129-10G</td>
			<td style="width:729px;">Evans blue dye</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Function generator</td>
			<td style="width:240px;">Tektronix</td>
			<td style="width:197px;">AFG3022B</td>
			<td>Dual channel, 250MS/s, 25MHz</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">FUS transducer, 1.1MHz</td>
			<td style="width:240px;">FUS Instruments</td>
			<td>TX-110</td>
			<td>1 MHz MRI-compatible spherically focused ultrasound transducer with a hydrophone</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Heating pad for Mice and Rats</td>
			<td style="width:240px;">Kent Scientific</td>
			<td style="width:197px;">PS-03</td>
			<td>Heating pad- PhysioSuite for Mice and Rats</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Infusion pump</td>
			<td style="width:240px;">KD Scientific</td>
			<td style="width:197px;">780100</td>
			<td>KDS 100 Legacy Single Syringe Infusion Pump</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Kapton tape</td>
			<td style="width:240px;">Gizmo Dorks</td>
			<td>https://www.amazon.com/dp/B01N1GGKRC/ 
			ref=cm_sw_em_r_mt_dp_U_GbR7Db56HKD91</td>
			<td>Gizmo Dorks Kapton Tape (Polyimide) for 3D Printers and Printing, 8 x 8 inches, 10 Sheets per Pack</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Low power immersion transducer, 1MHz</td>
			<td style="width:240px;">Olympus</td>
			<td>V303-SU</td>
			<td>Immersion Transducer, 1 MHz, 0.50 in. Element Diameter, Standard Case Style, Straight UHF Connector, F=0.80IN PTF</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Magnet sets</td>
			<td style="width:240px;">WINOMO</td>
			<td>https://www.amazon.com/dp/B01DJZQJBG/ 
			ref=cm_sw_em_r_mt_dp_U_JYQ7DbM32E5QC</td>
			<td>WINOMO 15mm Sew In Magnetic Bag Clasps for Sewing Scrapbooking - 10 Sets</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">RF amplifier</td>
			<td style="width:240px;">E&#38;I</td>
			<td style="width:197px;">A075</td>
			<td>75W</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Tail vein catheter</td>
			<td style="width:240px;">BD</td>
			<td>382512/ Fisher Item: NC1228513</td>
			<td>24g BD Insyte Autoguard shielded IV catheters (non-winged)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Ultrasound contrast microbubbles</td>
			<td>Lantheus Medical Imaging</td>
			<td style="width:197px;">DE4, DE16</td>
			<td>DEFINITY (Perflutren Lipid Microsphere)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Ultrasound gel</td>
			<td style="width:240px;">Aquasonic</td>
			<td>https://www.amazon.com/dp/B07FPQDM4F/ 
			ref=cm_sw_em_r_mt_dp_U_D6Q7Db3J9QP7P</td>
			<td>Ultrasound Gel Aquasonic 100 Transmission 1 Liter Squeeze Bottle</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Winged infusion sets, 22ga.</td>
			<td style="width:240px;">Fisher Healthcare</td>
			<td>22-258087</td>
			<td>Terumo Surflo Winged Infusion Sets</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">motor controller software</td>
			<td style="width:240px;">N/A</td>
			<td>N/A</td>
			<td style="width:729px;">custom software written in LabView for controlling the Velmex motor controller</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">runtime environment for the motor controller software</td>
			<td style="width:240px;">National Instruments</td>
			<td>LabView runtime engine version 2017 or better</td>
			<td>https://www.ni.com/en-us/support/downloads/software-products/download.labview.html</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">3 axis Linear stage actuator (XYZ positioner)</td>
			<td style="width:240px;">Velmex</td>
			<td style="width:197px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">bolts</td>
			<td style="width:240px;">Velmex</td>
			<td>MB-1</td>
			<td>BiSlide Bolt 1/4-20x3/4&#34; Socket cap screw (10 pack), Qty:3</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">motor controller</td>
			<td style="width:240px;">Velmex</td>
			<td>VXM-3</td>
			<td style="width:729px;">Control,3 axis programmable stepping motor control, Qty:1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">mounting cleats</td>
			<td style="width:240px;">Velmex</td>
			<td>MC-2</td>
			<td>Cleat, 2 hole BiSlide, Qty:6</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">mounting cleats</td>
			<td style="width:240px;">Velmex</td>
			<td>MC-2</td>
			<td style="width:729px;">Cleat, 2 hole BiSlide, Qty:2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">usb to serial converter</td>
			<td style="width:240px;">Velmex</td>
			<td>VXM-USB-RS232</td>
			<td style="width:729px;">USB to RS232 Serial Communication Cable 10ft, Qty:1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">x-axis linear stage</td>
			<td style="width:240px;">Velmex</td>
			<td>MN10-0100-M02-21</td>
			<td style="width:729px;">BiSlide, travel=10 inch, 2 mm/rev, limits, NEMA 23, Qty:1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">x-axis stepper motor</td>
			<td style="width:240px;">Velmex</td>
			<td>PK266-03A-P1</td>
			<td>Vexta Type 23T2, Single Shaft Stepper Motor, Qty:1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">y-axis linear stage</td>
			<td style="width:240px;">Velmex</td>
			<td>MN10-0100-M02-21</td>
			<td>BiSlide, travel=10 inch, 2 mm/rev, limits, NEMA 23, Qty:1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">y-axis stepper motor</td>
			<td style="width:240px;">Velmex</td>
			<td>PK266-03A-P1</td>
			<td style="width:729px;">Vexta Type 23T2, Single Shaft Stepper Motor, Qty:1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">z-axis damper</td>
			<td style="width:240px;">Velmex</td>
			<td>D6CL-6.3F</td>
			<td style="width:729px;">D6CL Damper for Type 23 Double Shaft Stepper Motor, Qty:1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">z-axis linear stage</td>
			<td style="width:240px;">Velmex</td>
			<td>MN10-0100-M02-21</td>
			<td style="width:729px;">BiSlide, travel=10 inch, 2 mm/rev, limits, NEMA 23, Qty:1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">z-axis stepper motor</td>
			<td style="width:240px;">Velmex</td>
			<td>PK266-03B-P2</td>
			<td style="width:729px;">Vexta Type 23T2, Double Shaft Stepper Motor, Qty:1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">3D printable files</td>
			<td style="width:240px;"></td>
			<td style="width:197px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Immersion transducer mount and pointer</td>
			<td></td>
			<td style="width:197px;"></td>
			<td>https://www.tinkercad.com/things/cRgTthGXSRq</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Stereotaxic frame</td>
			<td></td>
			<td style="width:197px;"></td>
			<td>https://www.tinkercad.com/things/ilynoQcdqlH</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Stereotaxic frame holder</td>
			<td></td>
			<td style="width:197px;"></td>
			<td>https://www.tinkercad.com/things/aZNgqhBOHAX</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">9.4T small bore animal MRI</td>
			<td style="width:240px;">Bruker</td>
			<td style="width:197px;">Bruker BioSpec 94/20</td>
			<td>ParaVision version 5.1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">AAV9-hsyn-GFP</td>
			<td style="width:240px;">Addgene</td>
			<td style="width:197px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Cream hair remover</td>
			<td style="width:240px;">Church &#38; Dwight</td>
			<td style="width:197px;"></td>
			<td>Nair cream</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">gadobutrol MRI contrast agent</td>
			<td style="width:240px;">Bayer</td>
			<td style="width:197px;"></td>
			<td>Gadavist (Gadobutrol, 1mM/mL)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Stereotactic frame</td>
			<td style="width:240px;">Stoelting</td>
			<td style="width:197px;">#51500</td>
			<td>not MRI compatible</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">turnkey FUS delivery device</td>
			<td style="width:240px;">FUS Instruments</td>
			<td style="width:197px;">RK-300</td>
			<td style="width:729px;">ready to use MRI compatible FUS for rodents</td>
		</tr>
	</tbody>
</table>

a benchtop approach to the location specific blood brain barrier opening using focused ultrasound in a rat model

Stereotaxic Chirurgie ist der Goldstandard für lokalisierte Medikamente und Gen-Lieferung an das Nagetier Gehirn. Diese Technik hat viele Vorteile gegenüber der systemischen Lieferung einschließlich präziser Lokalisierung auf eine Zielhirnregion und Reduzierung von Nebenwirkungen. Die stereotaxic-Chirurgie ist jedoch hochinvasiv, was ihre translationale Wirksamkeit einschränkt, lange Erholungszeiten erfordert und Herausforderungen bietet, wenn sie mehrere Hirnregionen ins Visier nimmt. Fokussierter Ultraschall (FUS) kann in Kombination mit zirkulierenden Mikroblasen verwendet werden, um die Blut-Hirn-Schranke (BBB) in millimetergroßen Regionen vorübergehend zu öffnen. Dies ermöglicht die intrakranielle Lokalisierung systemisch gelieferter Agenten, die normalerweise nicht über die BBB verfügen können. Diese Technik bietet eine nichtinvasive Alternative zur stereotaxic-Chirurgie. Bislang ist diese Technik jedoch in neurowissenschaftlichen Laboratorien aufgrund des begrenzten Zugangs zu Geräten und standardisierten Methoden noch nicht weit verbreitet. Das übergeordnete Ziel dieses Protokolls ist es, einen Benchtop-Ansatz für die FUS BBB-Öffnung (BBBO) zu bieten, der erschwinglich und reproduzierbar ist und daher von jedem Labor problemlos übernommen werden kann.

Hier zeigen wir, dass fokussierter Ultraschall mit Mikroblasen eine lokalisierte BBB-Öffnung mit den oben angegebenen Parametern sowohl mit dem Low-Power-Tauchwandler (Abbildung 3) als auch mit dem FUS-Wandler (Abbildung 4) induzieren kann. Zunächst wurde in frühen Experimenten der Low-Power-Tauchwandler auf eine Gehirnhälfte entweder anterior (Abbildung 3b) oder medial (Abbildung 3a) ausgerichtet. ...

Watch this Scientific Journal Video about A Benchtop Approach to the Location Specific Blood Brain Barrier Opening using Focused Ultrasound in a Rat Model at JoVE.com

A Benchtop Approach to the Location Specific Blood Brain Barrier Opening using Focused Ultrasound in a Rat Model

Fokussierter Ultraschall mit Mikroblasenmitteln kann die Blut-Hirn-Schranke fokal und vorübergehend öffnen. Diese Technik wurde verwendet, um eine breite Palette von Agenten über die Blut-Hirn-Schranke zu liefern. Dieser Artikel enthält ein detailliertes Protokoll für die lokalisierte Lieferung an das Nagetierhirn mit oder ohne MRT-Führung.

Ein Benchtop-Ansatz zur standortspezifischen Blut-Hirn-Barriere-Öffnung mit fokussiertem Ultraschall in einem Rattenmodell

Stereotaxic surgery is the gold standard for localized drug and gene delivery to the rodent brain. This technique has many advantages over systemic ...

a-benchtop-approach-to-location-specific-blood-brain-barrier-opening

Research

JoVE Journal

Neuroscience

4.5K Aufrufe.  University of Alabama at Birmingham. Fokussierter Ultraschall mit Mikroblasenmitteln kann die Blut-Hirn-Schranke fokal und vorübergehend öffnen. Diese Technik wurde verwendet, um eine breite Palette von Agenten über die Blut-Hirn-Schranke zu liefern. Dieser Artikel enthält ein detailliertes Protokoll für die lokalisierte Lieferung an das Nagetierhirn mit oder ohne MRT-Führung.

Serie: A Benchtop Approach to the Location Specific Blood Brain Barrier Opening using Focused Ultrasound in a Rat Model

Functional Neuroimaging Using Ultrasonic Blood-brain Barrier Disruption and Manganese-enhanced MRI

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains technically challenging. One approach, Activation-Induced Manganese-enhanced MRI (AIM MRI), has been used successfully to map neuronal activity in rodents 1-5. In AIM MRI, Mn2+ acts a calcium analog and accumulates in depolarized neurons 6,7. Because Mn2+ shortens the T1 tissue property, regions of elevated neuronal activity will enhance in MRI. Furthermore, Mn2+ clears slowly from the activated regions; therefore, stimulation can be performed outside the magnet prior to imaging, enabling greater experimental flexibility. However, because Mn2+ does not readily cross the blood-brain barrier (BBB), the need to open the BBB has limited the use of AIM MRI, especially in mice.
One tool for opening the BBB is ultrasound. Though potentially damaging, if ultrasound is administered in combination with gas-filled microbubbles (i.e., ultrasound contrast agents), the acoustic pressure required for BBB opening is considerably lower. This combination of ultrasound and microbubbles can be used to reliably open the BBB without causing tissue damage 8-11.
Here, a method is presented for performing AIM MRI by using microbubbles and ultrasound to open the BBB. After an intravenous injection of perflutren microbubbles, an unfocused pulsed ultrasound beam is applied to the shaved mouse head for 3 minutes. For simplicity, we refer to this technique of BBB Opening with Microbubbles and UltraSound as BOMUS 12. Using BOMUS to open the BBB throughout both cerebral hemispheres, manganese is administered to the whole mouse brain. After experimental stimulation of the lightly sedated mice, AIM MRI is used to map the neuronal response.
To demonstrate this approach, herein BOMUS and AIM MRI are used to map unilateral mechanical stimulation of the vibrissae in lightly sedated mice 13. Because BOMUS can open the BBB throughout both hemispheres, the unstimulated side of the brain is used to control for nonspecific background stimulation. The resultant 3D activation map agrees well with published representations of the vibrissae regions of the barrel field cortex 14. The ultrasonic opening of the BBB is fast, noninvasive, and reversible; and thus this approach is suitable for high-throughput and/or longitudinal studies in awake mice.

A technique is described for broadly opening the blood-brain barrier in the mouse using microbubbles and ultrasound. Using this technique, manganese can be administered to the mouse brain. Because manganese is an MRI contrast agent that accumulates in depolarized neurons, this approach enables imaging of neuronal activity.

Funktionelle Bildgebung mit Ultraschall-Blut-Hirnschranke Störung und Mangan-MRT

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains ...

Forschung

Neurowissenschaften

Stereotaxic Surgery for Excitotoxic Lesion of Specific Brain Areas in the Adult Rat

Many behavioral functions in mammals, including rodents and humans, are mediated principally by discrete brain regions. A common method for discerning the function of various brain regions for behavior or other experimental outcomes is to implement a localized ablation of function. In humans, patient populations with localized brain lesions are often studied for deficits, in hopes of revealing the underlying function of the damaged area. In rodents, one can experimentally induce lesions of specific brain regions.
Lesion can be accomplished in several ways. Electrolytic lesions can cause localized damage but will damage a variety of cell types as well as traversing fibers from other brain regions that happen to be near the lesion site. Inducible genetic techniques using cell-type specific promoters may also enable site-specific targeting. These techniques are complex and not always practical depending on the target brain area. Excitotoxic lesion using stereotaxic surgery, by contrast, is one of the most reliable and practical methods of lesioning excitatory neurons without damaging local glial cells or traversing fibers.
Here, we present a protocol for stereotaxic infusion of the excitotoxin, N-methyl-D-aspartate (NMDA), into the basolateral amygdala complex. Using anatomical indications, we apply stereotaxic coordinates to determine the location of our target brain region and lower an injection needle in place just above the target. We then infuse our excitotoxin into the brain, resulting in excitotoxic death of nearby neurons. While our experimental subject of choice is a rat, the same methods can be applied to other mammals, with the appropriate adjustments in equipment and coordinates.
This method can be used on a variety of brain regions, including the basolateral amygdala1-6, other amygdala nuclei6, 7, hippocampus8, entorhinal cortex9 and prefrontal cortex10. It can also be used to infuse biological compounds such as viral vectors1, 11. The basic stereotaxic technique could also be adapted for implantation of more permanent osmotic pumps, allowing more prolonged exposure to a compound of interest.

Targeted ablation of specific brain region(s) by infusion of an excitotoxin using stereotaxic coordinates is described. This technique could also be adapted for infusion of other chemicals into the rat brain.

Stereotaktischen Chirurgie für Exzitotoxische Läsion Spezifische Hirnareale in der erwachsenen Ratte

Many behavioral functions in mammals, including rodents and humans, are mediated principally by discrete brain regions. A common method for discerning the ...

An In Vivo Assessment of Blood-Brain Barrier Disruption in a Rat Model of Ischemic Stroke

Ischemic stroke leads to vasogenic cerebral edema and subsequent primary brain injury, which is mediated through destruction of the blood-brain barrier (BBB). Rats with induced ischemic stroke were established and used as in vivo models to investigate the functional integrity of the BBB. Spectrophotometric detection of Evans blue (EB) in the brain samples with ischemic injury could provide reliable justification for the research and development of novel therapeutic modalities. This method generates reproducible results, and is applicable in any laboratory without a need for special equipment. Here, we present a visualized and technical guideline on the detection of the extravasation of EB following induction of ischemic stroke in rats.

An In Vivo Assessment of Blood-Brain Barrier Disruption in a Rat Model of Ischemic Stroke

The overall goal of this procedure is to provide a highly reproducible technique for in vivo assessment of the blood-brain barrier disruption in rat models of ischemic stroke.

Eine In-Vivo -Bewertung der Störung der Blut - Hirn-Schranke in einem Rattenmodell des ischämischen Schlaganfalls

Ischemic stroke leads to vasogenic cerebral edema and subsequent primary brain injury, which is mediated through destruction of the blood-brain barrier ...

An Alternative Approach to Study Primary Events in Neurodegeneration Using Ex Vivo Rat Brain Slices

Despite&#160;numerous studies that attempt to develop reliable animal models&#160;which reflecting the primary processes underlying neurodegeneration, very few have been widely accepted. Here, we propose&#160;a new procedure&#160;adapted from the well-known ex vivo brain slice technique, which offers a closer in vivo-like scenario than in vitro preparations, for investigating the early events triggering cell degeneration, as observed in Alzheimer&#39;s disease (AD). This variation consists of simple and easily reproducible steps, which enable preservation of the anatomical cytoarchitecture of the selected brain region and its local functionality in a physiological milieu. Different anatomical areas can be obtained from the same brain, providing the opportunity to perform multiple experiments with the treatments in question in a site-, dose-, and time-dependent manner. Potential limitations&#160;which could affect the outcomes related to this methodology are related to the conservation of the tissue, i.e., the maintenance of its anatomical integrity during the slicing and incubation steps and the section thickness, which can influence the biochemical and immunohistochemical analysis. This approach can be employed for different purposes, such as exploring molecular mechanisms involved in physiological or pathological conditions, drug screening, or dose-response assays. Finally, this protocol could also reduce the number of animals employed in behavioral studies. The application reported here has been recently described and tested for the first time on ex vivo rat brain slices containing the basal forebrain (BF), which is one of the cerebral regions primarily affected in AD. Specifically, it has been demonstrated that the administration of a toxic peptide derived from the C-terminus of acetylcholinesterase (AChE) could prompt an AD-like profile, triggering, along the antero-posterior axis of the BF, a differential expression of proteins altered in AD, such as the alpha7 nicotinic receptor (&#945;7-nAChR), phosphorylated Tau (p-Tau), and amyloid beta (A&#946;).

An Alternative Approach to Study Primary Events in Neurodegeneration Using Ex Vivo Rat Brain Slices

We present a method which can&#160;provide further insights into the early events underlying neurodegeneration and based on the established ex-vivo brain technique, combining the advantages of in vivo and in vitro experiments. Moreover, it represents a unique opportunity for direct comparison of treated and untreated group in the same anatomical plane.

Ein alternativer Ansatz zur primären Ereignissen in Neurodegeneration mit Ex Vivo Ratte Gehirnscheiben studieren

Despite&#160;numerous studies that attempt to develop reliable animal models&#160;which reflecting the primary processes underlying neurodegeneration, ...

A Human Blood-Brain Interface Model to Study Barrier Crossings by Pathogens or Medicines and Their Interactions with the Brain

The early screening of nervous system medicines on a pertinent and reliable in cellulo BBB model for their penetration and their interaction with the barrier and the brain parenchyma is still an unmet need. To fill this gap, we designed a 2D in cellulo model, the BBB-Minibrain, by combining a polyester porous membrane culture insert human BBB model with a Minibrain formed by a tri-culture of human brain cells (neurons, astrocytes and microglial cells). The BBB-Minibrain allowed us to test the transport of a neuroprotective drug candidate (e.g., Neurovita), through the BBB, to determine the specific targeting of this molecule to neurons and to show that the neuroprotective property of the drug was preserved after the drug had crossed the BBB. We have also demonstrated that BBB-Minibrain constitutes an interesting model to detect the passage of virus particles across the endothelial cells barrier and to monitor the infection of the Minibrain by neuroinvasive virus particles. The BBB-Minibrain is a reliable system, easy to handle for researcher trained in cell culture technology and predictive of the brain cells phenotypes after treatment or insult. The interest of such in cellulo testing would be twofold: introducing derisking steps early in the drug development on the one hand and reducing the use of animal testing on the other hand.

Here we present a protocol describing the setting of an in cellulo BBB (Blood brain barrier)-Minibrain polyester porous membrane culture insert system in order to evaluate the transport of biomolecules or infectious agents across a human BBB and their physiological impact on the neighboring brain cells.

Ein menschliches Blut-Hirn-Schnittstellenmodell Barriere Kreuzungen durch Krankheitserreger oder Medikamente und ihre Wechselwirkungen mit dem Gehirn zu studieren

The early screening of nervous system medicines on a pertinent and reliable in cellulo BBB model for their penetration and their interaction with the ...

A High-Throughput Image-Guided Stereotactic Neuronavigation and Focused Ultrasound System for Blood-Brain Barrier Opening in Rodents

The blood-brain barrier (BBB) has been a major hurdle for the treatment of various brain diseases. Endothelial cells, connected by tight junctions, form a physiological barrier preventing large molecules (&#62;500 Da) from entering the brain tissue. Microbubble-mediated focused ultrasound (FUS) can be used to induce a transient local BBB opening, allowing larger drugs to enter the brain parenchyma.
In addition to large-scale clinical devices for clinical translation, preclinical research for therapy response assessment of drug candidates requires dedicated small animal ultrasound setups for targeted BBB opening. Preferably, these systems allow high-throughput workflows with both high-spatial precision as well as integrated cavitation monitoring, while still being cost effective in both initial investment and running costs.
Here, we present a bioluminescence and X-ray guided stereotactic small animal FUS system that is based on commercially available components and fulfills the aforementioned requirements. A particular emphasis has been placed on a high degree of automation facilitating the challenges typically encountered in high-volume preclinical drug evaluation studies. Examples of these challenges are the need for standardization in order to ensure data reproducibility, reduce intra-group variability, reduce sample size and thus comply with ethical requirements and decrease unnecessary workload. The proposed BBB system has been validated in the scope of BBB opening facilitated drug delivery trials on patient-derived xenograft models of glioblastoma multiforme and diffuse midline glioma.

The blood-brain barrier (BBB) can be temporarily disrupted with microbubble-mediated focused ultrasound (FUS). Here, we describe a step-by-step protocol for high-throughput BBB opening in vivo using a modular FUS system accessible for non-ultrasound experts.

Ein hochdurchsatzgesteuertes, stereotaktisches Neuronavigations- und fokussiertes Ultraschallsystem für die Öffnung der Blut-Hirn-Barriere bei Nagetieren

The blood-brain barrier (BBB) has been a major hurdle for the treatment of various brain diseases. Endothelial cells, connected by tight junctions, form a ...

Focused Ultrasound Induced Blood-Brain Barrier Opening for Targeting Brain Structures and Evaluating Chemogenetic Neuromodulation

Acoustically Targeted Chemogenetics (ATAC) allows for the noninvasive control of specific neural circuits. ATAC achieves such control through a combination of focused ultrasound (FUS) induced blood-brain barrier opening (FUS-BBBO), gene delivery with adeno-associated viral (AAV) vectors, and activation of cellular signaling with engineered, chemogenetic, protein receptors and their cognate ligands. With ATAC, it is possible to transduce both large and small brain regions with millimeter precision using a single noninvasive ultrasound application. This transduction can later allow for a long-term, noninvasive, device-free neuromodulation in freely moving animals using a drug. Since FUS-BBBO, AAVs, and chemogenetics have been used in multiple animals, ATAC should also be scalable for the use in other animal species. This paper expands upon a previously published protocol and outlines how to optimize the gene delivery with FUS-BBBO to small brain regions with MRI-guidance but without a need for a complicated MRI-compatible FUS device. The protocol, also, describes the design of mouse targeting and restraint components that can be 3D-printed by any lab and can be easily modified for different species or custom equipment. To aid reproducibility, the protocol describes in detail how the microbubbles, AAVs, and venipuncture were used in ATAC development. Finally, an example data is shown to guide the preliminary investigations of studies utilizing ATAC.

This protocol delineates steps necessary for the gene delivery through focused ultrasound blood brain barrier (BBB) opening, evaluation of the resulting gene expression, and measurement of neuromodulation activity of chemogenetic receptors through histological tests.

Fokussierte ultraschallinduzierte Öffnung der Blut-Hirn-Schranke zur gezielten Behandlung von Hirnstrukturen und zur Beurteilung der chemogenetischen Neuromodulation

Acoustically Targeted Chemogenetics (ATAC) allows for the noninvasive control of specific neural circuits. ATAC achieves such control through a ...

Delivery of Antibodies into the Brain Using Focused Scanning Ultrasound

Only a small fraction of therapeutic antibodies targeting brain diseases are taken up by the brain. Focused ultrasound offers a possibility to increase uptake of antibodies and engagement through transient opening of the blood-brain barrier (BBB). In our laboratory, we are developing therapeutic approaches for neurodegenerative diseases in which an antibody in various formats is delivered across the BBB using microbubbles, concomitant with focused ultrasound application through the skull targeting multiple spots, an approach we refer to as scanning ultrasound (SUS). The mechanical effects of microbubbles and ultrasound on blood vessels increases paracellular transport across the BBB by transiently separating tight junctions and enhances vesicle- mediated transcytosis, allowing antibodies and therapeutic agents to effectively cross. Moreover, ultrasound also facilitates the uptake of antibodies from the interstitial brain into brain cells such as neurons where the antibody distributes throughout the cell body and even into neuritic processes. In our studies, fluorescently labeled antibodies are prepared, mixed with in-house prepared lipid-based microbubbles and injected into mice immediately before SUS is applied to the brain. The increased antibody concentration in the brain is then quantified. To account for alterations in normal brain homeostasis, microglial phagocytosis can be used as a cellular marker. The generated data suggest that ultrasound delivery of antibodies is an attractive approach to treat neurodegenerative diseases.

Presented here is a protocol to transiently open the blood-brain barrier (BBB) either focally or throughout a mouse brain to deliver fluorescently-labeled antibodies and activate microglia. Also presented is a method to detect the delivery of antibodies and microglia activation by histology.

Abgabe von Antikörpern in das Gehirn mittels fokussiertem Scanning-Ultraschall

Only a small fraction of therapeutic antibodies targeting brain diseases are taken up by the brain. Focused ultrasound offers a possibility to increase ...

A Rat Model of EcoHIV Brain Infection

It has been well studied that the EcoHIV infected mouse model is of significant utility in investigating HIV associated neurological complications. Establishment of the EcoHIV infected rat model for studies of drug abuse and neurocognitive disorders, would be beneficial in the study of neuroHIV and HIV-1 associated neurocognitive disorders (HAND). In the present study, we demonstrate the successful creation of a rat model of active HIV infection using chimeric HIV (EcoHIV). First, the lentiviral construct of EcoHIV was packaged in cultured 293 FT cells for 48 hours. Then, the conditional medium was concentrated and titered. Next, we performed bilateral stereotaxic injections of the EcoHIV-EGFP into F344/N rat brain tissue. One week after infection, EGFP fluorescence signals were detected in the infected brain tissue, indicating that EcoHIV successfully induces an active HIV infection in rats. In addition, immunostaining for the microglial cell marker, Iba1, was performed. The results indicated that microglia were the predominant cell type harboring EcoHIV. Furthermore, EcoHIV rats exhibited alterations in temporal processing, a potential underlying neurobehavioral mechanism of HAND as well as synaptic dysfunction eight weeks after infection. Collectively, the present study extends the EcoHIV model of HIV-1 infection to the rat offering a valuable biological system to study HIV-1 viral reservoirs in the brain as well as HAND and associated comorbidities such as drug abuse.

Here, we present a protocol to establish a new rat model of active HIV infection using chimeric HIV (EcoHIV), which is critical for enhancing our understanding of HIV-1 viral reservoirs in the brain and offering a system to study HIV-associated neurocognitive disorders and associated comorbidities (i.e., drug abuse).

Ein Rattenmodell der EcoHIV-Gehirninfektion

It has been well studied that the EcoHIV infected mouse model is of significant utility in investigating HIV associated neurological complications. ...

Ein 3D-Blut-Hirn-Schranken-Modell, das aus menschlichen pluripotenten Stammzellen gewonnen wurde

Reconstruction of the Blood-Brain Barrier In Vitro to Model and Therapeutically Target Neurological Disease

The blood-brain barrier (BBB) is a key physiological component of the central nervous system (CNS), maintaining nutrients, clearing waste, and protecting the brain from pathogens. The inherent barrier properties of the BBB pose a challenge for therapeutic drug delivery into the CNS to treat neurological diseases. Impaired BBB function has been related to neurological disease. Cerebral amyloid angiopathy (CAA), the deposition of amyloid in the cerebral vasculature leading to a compromised BBB, is a co-morbidity in most cases of Alzheimer&#39;s disease (AD), suggesting that BBB dysfunction or breakdown may be involved in neurodegeneration. Due to limited access to human BBB tissue, the mechanisms that contribute to proper BBB function and BBB degeneration remain unknown. To address these limitations, we have developed a human pluripotent stem cell-derived BBB (iBBB) by incorporating endothelial cells, pericytes, and astrocytes in a 3D matrix. The iBBB self-assembles to recapitulate the anatomy and cellular interactions present in the BBB. Seeding iBBBs with amyloid captures key aspects of CAA. Additionally, the iBBB offers a flexible platform to modulate genetic and environmental factors implicated in cerebrovascular disease and neurodegeneration, to investigate how genetics and lifestyle affect disease risk. Finally, the iBBB can be used for drug screening and medicinal chemistry studies to optimize therapeutic&#160;delivery to the CNS. In this protocol, we describe the differentiation of the three types of cells (endothelial cells, pericytes, and astrocytes) arising from human pluripotent stem cells, how to assemble the differentiated cells into the iBBB, and how to model CAA in vitro using exogenous amyloid. This model overcomes the challenge of studying live human brain tissue with a system that has both biological fidelity and experimental flexibility, and enables the interrogation of the human BBB and its role in neurodegeneration.

Autor im Rampenlicht: Ein personalisierter Ansatz zur Erforschung der Alzheimer-Krankheit unter Verwendung eines In-vitro-Blut-Hirn-Schrankenmodells 

The blood-brain barrier (BBB) has a crucial role in sustaining a stable and healthy brain environment. BBB dysfunction is associated with many neurological diseases. We have developed a 3D, stem-cell-derived model of the BBB to investigate cerebrovascular pathology, BBB integrity, and how the BBB is altered by genetics and disease.

Rekonstruktion der Blut-Hirn-Schranke in vitro zur Modellierung und therapeutischen Behandlung neurologischer Erkrankungen

The blood-brain barrier (BBB) is a key physiological component of the central nervous system (CNS), maintaining nutrients, clearing waste, and protecting ...