How to use an automatic brain stereotaxic apparatus


The automatic brain stereotaxic instrument is an important research instrument in neuroanatomy, neurophysiology, neuropharmacology and neurosurgery. Fully automatic stereotaxic instruments have been widely used for accurate localization of brain injury, neurostimulation, and EEG recordings, and have become an essential tool for studying brain structure and function.

1. Animal anesthesia: Mice, weighing 20-30g, were anesthetized and injected with 0.4% pentobarbital sodium after weighing. The injection must be slow, and the state of the animal should be paid attention to at any time.

2. Mouse head fixation: fix the mouse's incisors on the maxillary fixator of the automatic stereotaxic apparatus, and then push the ear holder on one side into the animal's outer canal, so that the animal's head is in the middle of the two slides. Push the other ear cuff into the external ear canal on the other side. At this time, after observing that the scales of the two ear sticks are consistent, tighten the fixing screws on the two ear sticks, and then tighten the nose ring on the tooth holder after pressing down (the tightness of the nose ring and ear sticks should be adjusted appropriately). ), then pushing the animal's head from all directions will not move.

3. Skin preparation before craniotomy: cut off the animal head hair, disinfect the head skin with 2% iodine and 75% alcohol cotton balls, make a -3cm long skin incision along the sagittal suture, and separate the subcutaneous The fascia and muscles on the surface of the skull were cleaned with hydrogen peroxide and peeled off, and the periosteum was pushed away to expose the bregma, herringbone suture and sagittal suture.

4. Determine the standard midline: move the metal positioning needle down above the sagittal suture, and then move the positioning needle back and forth to position the positioning needle to the bregma.

5. Mouse positioning: use a positioning needle to locate a point 2 mm behind the bregma and 2.5 mm beside the sagittal suture, which is the plane position of the mouse, and then drill a small circle on the skull with a drilling needle at this point hole.

6. Drug injection: The mouse is located 2mm below the circular hole, and the 1ml syringe is inhaled and placed on the micromanipulator. When the needle of the syringe drops 2mm from the hole in the mouse brain, the drug is injected into the hippocampus of the mouse. .

7. Making brain tissue slices: The mouse brain was made into slices, and the position of red dye in the mouse brain was observed microscopically to verify whether the location in the mouse hippocampus was accurate.