Assessment of Neurovascular Coupling - Animal Models of Acute Neurological Injuries: Injury and Mechanistic Assessments - page 337

closed cranial window preparations in anesthetized, artifi cially
ventilated animals. The window preparation enables topical super-
fusion of drugs or specifi c composition of the cerebrospinal fl uid
( 2, 16 ). Here, general surgery and the technique of cranial window
preparation are described, and frequently used methods for experi-
mental rCBF measurements are introduced. The choice of prepa-
ration and method of rCBF monitoring depends on the specifi c
paradigm, as for example intracortical microelectrode recordings
require an open window preparation. According to the addressed
questions, chronic cranial window preparations might need certain
adaptations ( 17, 18 ). The techniques are described mainly for use
in rats, but can be modifi ed for other rodent species like the mouse
( 19, 20 ).
The following gives an overview.

Total time required for a cranial window implantation (well-trained
microsurgeon): ~150-210 min (without time needed for
measurements).
Preparation of artifi cial cerebrospinal fl uid (aCSF): ~15 min.
General surgery: 30-45 min (anesthesia, tracheotomy, ventilation
adjustment, vessel cannulation, animal placement in stereo-
taxic frame).
Window preparation: 60-90 min (skull exposure and cleaning,
drilling, dura removal).
Placement of microelectrodes and the device for rCBF measure-
ment: 15-30 min.
Test for artifacts and incubation period: 30 min.

2.1. General
Instruments
and Material

Animals :
Rats: 220-350 g (commonly Sprague Dawley or Wistar).
Surgery :
Dissecting (stereo-)microscope.
Anesthesia (see below).
Lidocaine solution 1%, for local application (ear plugs/incisions).
aCSF (see below).
Bone wax.
Polyethylene tubing for vessel cannulation (PE 50).
Tracheal tube (Portex, polythene tubing, Smiths Medical, ID 1.67,
OD 2.42).
Suture material.
Coverslips.
Dental cement for cranial window fi xation (Paladur, Heraeus
Kulzer GmbH, Germany).