Chapter 9 Basic Experiments of NeurobiologyExperiment 1 Brain Stereotaxic Technique

Functional Experimental Science

Content

Experimental objectives 1

Experimental procedures 2

Precautions 3

Results4

Discussion5

Experimental Objectives

By performing the experiment, you are expected to be fam

iliar with primary structure, principle and operating method o

f stereotaxic apparatus, to be familiar with the method for loca

ting the nucleus in brain and intracerebroventricular micro- i

njection with stereotaxic apparatus, to have a through grasp of

usage of animal brain atlas.

Experimental Procedures

General anesthesia and fixation 1

An adult rat weighing 200~230g is anesthetized with 4% chlor

al hydrate (400 mg/kg, i.p.).

the ear bars should be gently inserted into the external

auditory meatus, and the head is kept in the middle. The

upper incisor is inserted into the hole of incisor plate,

Experimental Procedures

Craniotomy and positioning2

• After hair clearance and regular disinfection, a 1 cm long incision is cut along sagittal suture. The skull surface is wiped with hydrogen peroxide to expose the bregma and lambda, as well as the coronal and sagittal sutures .

• According to the coordinates of lateral ventricle (Fig 9-4), a small hole is punched on the skull with a dental drill..

Experimental Procedures

Microinjection to the lateral ventricle 3

• The rat is slowly injected via the lateral ventricle (LV) with 10~20 μl blue ink by a microsyringe.

•The syringe should be removed 3-5 min later in order to prevent the retrograde flow of ink.

Experimental Procedures

Observations4

• The brain should be taken out from the cranium and be cut

coronally with a razor blade to verify whether blue ink is in the

lateral ventricle.

Precautions The structure of stereotaxic apparatus is very delicate and easily injured, so the manipulation should be very gentle and avoid any forced movement..

1

When the sliding rules are adjusted three-dimensionally, it should be verified whether the sliding rules of three plans are perpendicular to each other.

2

The ear plugs should be inserted exactly into the external auditory meatus, and symmetrically from both sides in order to keep the rat head at the middle position in the stereotaxic apparatus. Be sure to prevent the external auditory meatus from being misplugged, soft tissue from embedding and readings on two sides from being asymmetry..

3

Results

It could be find that blue ink is in the third ventricle.

1

2

Blue ink is in the lateral ventricle.