Biology Reference
In-Depth Information
Chapter 13
Rodent Behavioral Assessment in the Home Cage
Using the SmartCage™ System
Xinmin Simon Xie , Jingxi Zhang , Bende Zou , James Xie ,
Jidong Fang , Nurulain T. Zaveri , and Taline V. Khroyan
Abstract
The combination of molecular manipulation of gene expression and behavior endpoint phenotypic analysis
has uncovered numerous novel gene functions and provided unprecedented opportunities for new drug
development. To facilitate investigation of diverse behavioral processes, we have developed a home cage
monitoring system for automated rodent neurobehavioral phenotypic analysis and higher-throughput
in vivo drug screening. This system termed SmartCage™ measures rodents' behavior in their home cages
as a signifi cant endpoint. The SmartCage™ system consists of multiple instrument platforms that interface
with ordinary rodent home cages. Each SmartCage™ is comprised of multiple sensors including a fl oor-
vibration sensor, an infrared (IR) matrix and fl exible modular devices. This system is noninvasive and
allows the animal to be tested in its home cage that has bedding, food, and water, making it appropriate to
monitor animals for days or weeks. The automated measurements include wake and sleep/inactive states.
The active parameters include locomotion, rearing, and animal movement patterns, for example, rotations
(cycling). In validating the system, we fi rst compared it with conventional technologies, e.g., video camera
recording. The results indicate a strong correlation between imaging tracking and IR detection. Next we
used pharmacological tools (both stimulant and activity inhibitors) to further validate the system, which
demonstrated that SmartCage™ is sensitive enough to detect drug-induced increases and decreases in
activity levels. Secondly, wake and sleep state automated classifi cation by the SmartCage™ was validated by
comparing it with simultaneously recorded electroencephalograph (EEG)/electromyograph (EMG) data.
This comparison confi rms that the fl oor-sensor can provide up to 85-90% accuracy in estimating sleep
states.
Using modular devices incorporated into the SmartCage™ platform, other behavioral measures can
be collected. For example, a new rotarod device can be fl exibly installed in the SmartCage™ system. The
manual rotarod test can be conducted in a similar manner as the conventional rotarod test. That is, the
researcher placing the mouse onto the rod and then start the test. Using this new device, spontaneous
performance of rotarod test is automatically initiated by the animal at its home cage. The duration of stay-
ing on the rotating rod and numbers of spontaneous performance are signifi cantly different between
middle cerebral arterial occlusion (MCAO) and sham control mice. Another modular insert includes a dark
box that can be placed directly into the animal's home cage and our initial tests indicate that the SmartCage™
can detect diazepam-induced anxiolytic effects. The result is comparable to those obtained using conven-
tional anxiety tests such as the elevated plus T-maze and Zero-maze.
Search WWH ::
Custom Search