Vol. 283, Issue 4, H1713-H1719, October 2002
SPECIAL COMMUNICATIONS
An implantable bolus infusion pump for use in freely moving,
nontethered rats
D. P.
Holschneider1,2,4,
J.-M. I.
Maarek3,
J.
Harimoto3,
J.
Yang1, and
O. U.
Scremin4,5
1 Department of Psychiatry and the Behavioral
Sciences; 2 Department of Neurology, University of
Southern California School of Medicine, Los Angeles 90033;
3 Department of Biomedical Engineering, University of
Southern California School of Engineering, Los Angeles 90089;
4 Greater Los Angeles Veterans Affairs Healthcare
System, Los Angeles 90073; and 5 Department of
Physiology, University of California at Los Angeles School of
Medicine, Los Angeles, California 90095
One of the current constraints on
functional neuroimaging in animals is that to avoid movement artifacts
during data acquisition, subjects need to be immobilized, sedated, or
anesthetized. Such measures limit the behaviors that can be examined,
and introduce the additional variables of stress or anesthetic agents
that may confound meaningful interpretation. This study provides a
description of the design and characteristics of a self-contained,
implantable microbolus infusion pump (MIP) that allows triggering of a
bolus injection at a distance in conscious, behaving rats that are not restrained or tethered. The MIP is externally triggered by a pulse of
infrared light and allows in vivo bolus drug delivery. We describe application of this technology to the intravenous bolus delivery of
iodo[14C]antipyrine in a freely moving animal, followed
immediately by lethal injection, rapid removal of the brain, and
analysis of regional cerebral blood flow tissue radioactivity with the
use of autoradiography. The ability to investigate changes in brain activation in nonrestrained animals makes the MIP a powerful tool for
evaluation of complex behaviors.
drug delivery; functional neuroimaging; cerebral blood flow; iodo-antipyrine; autoradiography
