Inducing Neuroinflammation in Zebrafish Larvae with a Lipopolysaccharide Injection

Abstract

Source: He, Y. et al. Brain Ventricular Microinjections of Lipopolysaccharide into Larval Zebrafish to Assess Neuroinflammation and Neurotoxicity. J. Vis. Exp. (2022).

The video demonstrates the microinjection of lipopolysaccharides (LPS) into the brains of zebrafish larvae to induce neuroinflammation. The larvae are positioned on an agarose-lined dish, the needle is inserted into the brain ventricles, and the LPS is injected. The injected LPS triggers an immune response that leads to neuroinflammation.

Protocol

1. Preparing for microinjection

1. Prepare for the injection by pulling glass capillaries using a micropipette puller (see Table of Materials), following the five-step protocol for glass capillary tube pulling (Table 1).
2. Open the tip of the needle (thin wall glass capillaries [3.5 in] with filament, outer diameter [OD] 1.14 mm) to the appropriate size at an angle using forceps (Figure 1A).
3. Fill the needle with 0.1 mL of mineral oil to ensure that there are no bubbles.
4. Remove the screw cap of the steel needle of the microinjection apparatus. Align the glass needle hole with the s....

Results

Table 1: Five-step protocol for glass capillary tube pulling.

Step	Operating time (sec)	Heat level	Action
T1	L>	H80-89	P1L005
T2	1.6-3	H00

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Agarose	Sigma-Aldrich	A6361
Agarose, low gelling temperature	Sigma-Aldrich	A9414
Drummond Nanoject III Programmable Nanoliter Injector	Drummond Scientific	3-000-207
Fluorescence stereo microscopes	Leica	M205 FA
Lipopolysaccharides from Escherichia coli O111:B4	Sigma-Aldrich	L3024
Manual micromanipulator	World Precision Instruments	M3301
Mineral oil	Sigma-Aldrich	M5904
Phosphate-buffered saline	Sigma-Aldrich	P4417
Thin wall glass capillaries (4") with filament, OD 1.5 mm	World Precision Instruments	TW150F-4
Tricaine (3-amino benzoic acid ethyl ester)	Sigma-Aldrich	A-5040