Rodent Behavioral Assessment in the Home Cage Using the SmartCage System - Animal Models of Acute Neurological Injuries: Injury and Mechanistic Assessments - page 196

In conclusion, this noninvasive integrated home cage monitoring system, SmartCage™, can provide
an automated assessment of rodent behavior to identify gene-altered phenotypes, to facilitate initial in vivo
drug screening, and to rapidly fi lter out neurobehavioral toxic compounds prior to testing in individual
disease models.

Key words: Neurobehavior, Rodents, Rats, Mice, Spontaneous activity, Locomotion, SmartCage,
Home cage, Behavior monitoring system, Anxiety, Sleep, Sedation

1. Introduction

1.1. Signifi cance
of Studying Rodent
Spontaneous Activity

Most instinctive behaviors observed in humans also occur in rodents.
The drives and emotions of hunger, sleep, sex, anger, fear and anxi-
ety, as well as the ability to learn, remember, and socialize can be
modeled in rodent models using mice. For example, in mice we can
use models to measure analgesia, anxiety, as well as reward. All of
these animal models can be used to interpret the underlying nature
of potential disease states observed in humans. Furthermore, mod-
eling human diseases with transgenic mice and their behavioral
responses to drugs is routinely used in the pharmaceutical industry
to evaluate the effi cacy and safety of early-stage drug candidates.
Pharmaceutical companies conduct behavioral studies to investigate
in vivo effi cacy and safety profi les of drug candidates identifi ed
in vitro from high-throughput screening (HTS) ( 1-4 ). Behavioral
neuroscience and behavioral genetics have also become important
fi elds of study at universities and research institutes ( 5, 6 ) and the
SmartCage™ system can help expedite data acquisition ( 7 ).
Given that arousal states, sleep, and locomotor activity are fun-
damental aspects of global nervous system function, it is essential
to examine these behaviors in rodent models. This is particularly
important since these simple behaviors can affect other more com-
plex behaviors, particularly physical performance and cognitive
function ( 8 ). For example, motor function disturbances are associ-
ated with CNS disorders, such as stroke, traumatic brain injury,
anxiety, depression, Parkinson's disease, and drug-caused CNS side
effects. Over the course of radiation therapy, for example, patients
commonly experience sleep disturbance, fatigue, and pain.
Therefore, assessment of spontaneous behaviors in animals should be
the initial step prior to other more sophisticated behavioral evalua-
tions and tests in specifi c disease models ( 9 ).
Researchers continually explore new models in vitro to under-
stand the human organism and disease processes, and to test new
chemical entities and vaccines. However, the validity of effi cacy and
safety results obtained from these model systems must still be veri-
fi ed in appropriate whole animal systems and appropriate disease
models before clinical trials with human volunteers or patients.
Therefore, it is important to conduct behavioral assessments, given
that behavior is the fi nal output of the nervous system at the level