Name: Kraniotomi med mus for intracerebroventrikulær injeksjon på frihånd
Uploaded: 2024-01-12T12:45:00
Description: Watch this Scientific Journal Video about Mouse Craniotomy for Free-Hand Intracerebroventricular Injection at JoVE.com

mouse craniotomy for free-hand intracerebroventricular injection

Utføre intracerebroventrikulær injeksjon hos mus ved hjelp av en frihåndstilnærming

The delivery of experimental agents, such as drugs1, viruses2, or cells3, to the brain is often necessary for neuroendocrine research. If the agent does not readily cross the blood-brain barrier or the experimental objective is to specifically test the central effects of the agent, it is important to have a reliable method for delivering injections into the brain. Moreover, injection into the intracerebroventricular (ICV) space provides the opportunity to distribute the agent widely in the brain and provides a large target area, thus increasing the likelihood of successful injection2. 
A common method for making ICV injections involves the placement of a permanent indwelling cannula. In this approach, a stereotaxic frame is necessary to position the commercially available or custom-made cannula, as the cannula is glued or cemented in place. Often, upon recovery, a supraphysiological dose of angiotensin II is administered through the cannula, and if drinking behavior is immediately observed, then the cannula is considered correctly placed4. This approach has many advantages, including the ability to perform long-term infusion and the ability to inject the same animal multiple times; additionally, if angiotensin II is employed, correct placement can be confirmed prior to the administration of experimental compounds. However, there are some limitations to placing a permanent cannula, including the requirement for expensive equipment (stereotaxic frame), the possibility of damage to the cannula after placement (e.g., mice can chew on the cannula of a cage mate), and the possibility of infections around the permanent cannula. Single ICV injections can be made with the use of a stereotaxic frame3, which, although effective, requires substantial exposure to anesthesia and, thus, may obscure some acute physiological and behavioral effects of the treatment. Additionally, the placement of mice in a stereotaxic frame requires substantial training to achieve stable placement and prevent the rupturing of the ear canals.
Here, an established method for making free-hand injections in mice is described. This method is based on previous reports5,6. The advantages of this technique are that it is simple, rapid, and does not require specialized equipment such as a stereotaxic frame. As described below, this procedure involves manipulating a glass syringe relative to landmarks on the mouse head to make the injections, which can be done rapidly and, thus, requires only a few minutes of gas anesthesia on the experimental day.

Forfatter Spotlight: Innsikt, innovasjoner og fremtidige veier innen reproduktiv nevrokontroll 

Frihånds intracerebroventrikulære injeksjoner hos mus

We are interested in the neural control of reproductive function, particularly how the brain regulates the release of hormones that control the gonads, both in healthy conditions and in response to stress. The main advantage of this technique is that it is relatively simple and rapid. Delivering drugs into the lateral ventricle is a great way to cast a wide net in testing a signaling pathway to support more detailed follow-up experiments.There's still much to be learned about the neuroendocrine control of reproduction, including the molecular mechanisms for luteinizing hormone pulse generation, mechanisms for modulating pulse frequency during stress, and generation of the preovulatory LH surge. In the future, we are particularly interested in integrating disparate findings into models.

Watch this Scientific Journal Video about Mouse Craniotomy for Free-Hand Intracerebroventricular Injection at JoVE.com

Kraniotomi med mus for intracerebroventrikulær injeksjon på frihånd

Begynn med å forberede deg på en kraniotomi ved å plassere en ren benkpute på arbeidsflaten. Teip nesekjeglen til en isofluran fordamper til arbeidsflaten. Plasser deretter silastslangen på enden av en 18-gauge nål, slik at en millimeter av nålespissen stikker ut.Øv nålbevegelse ved å merke et ark papir med utgangspunkt for bregma, en annen 0,2 millimeter lateralt, og lag et endelig merke, en millimeter kaudalt til det andre merket. Øv deg på å flytte nålen fra startpunktet til det andre merket, deretter det endelige merket, slik at bevegelsen kan gjentas uten føringer. Deretter barberer du hodet til det bedøvede dyret.Plasser musen på arbeidsflaten, hold hodet i nesekeglen for å opprettholde anestesi og bruk øyesmøremiddel på begge øynene. Skrubb nå injeksjonsstedet med sterilt gasbind dyppet i jodoppløsning. Tørk deretter området med en alkoholskrubbpute.Gjenta denne prosessen tre ganger. Hold hodet fast med den ikke-dominerende hånden, legg musen flatt på arbeidsflaten. Dra den forberedte 18-gauge nålen over hodehuden, langs midtlinjen i en rostral, kaudal retning for å identifisere bregma.Flytt nålen to millimeter lateralt og en millimeter caudal til injeksjonsstedet. Hold nålen vertikalt, skyv den bestemt gjennom huden og beinet, til slangen er flush med huden. Trekk nålen tilbake, roter og trykk gjennom huden og beinet igjen, gjenta prosessen for å lage et lite hull i beinet.Bruk den stumpe nålen, kontroller for et tilstrekkelig hull i beinet, stort nok til at nålen kan passere gjennom. Fjern musen fra nesekeglen. Fortsett med å rense blod fra injeksjonsstedet ved hjelp av sterilt gasbind.Plasser musen i et bur, på en burvarmer, til våken.

Research

JoVE Journal

Neuroscience

Mouse Craniotomy for Free-Hand Intracerebroventricular Injection

Free-Hand Intracerebroventricular Injections in Mice

The investigation of neuroendocrine systems often requires the delivery of drugs, viruses, or other experimental agents directly into the brains of mice. ...