Research Techniques for the Squirrel Monkey (Saimiri sp.)

Abstract

S quirrel monkeys are useful animal models in a variety of different research disciplines in biomedical research. To properly utilize these animals, it is important that research techniques are properly suited to the unique characteristics of this genus. To consider squirrel monkeys as "miniaturized macaques," or a slightly different version of another animal model, is to underestimate both the potential and the pitfalls of using these animals in research.

Early life stress and novelty seeking behavior in adolescent monkeys

“…Group composition was determined by infant birth dates to minimize developmental differences between infants in the same natal group. Puberty occurs between 2.5 -3.5 years of age in squirrel monkeys, and their average maximum lifespan in captivity is ~21 years of age (Baldwin 1985;Brady 2000). All procedures were approved by Stanford University's Administrative Panel on Laboratory Animal Care and were carried out in accordance with the National Institutes of Health's Guide for the Care and Use of Laboratory Animals.…”

Preliminary Evidence That Hippocampal Volumes in Monkeys Predict Stress Levels of Adrenocorticotropic Hormone

“…After weaning, at 9 months of age, all monkeys were socially housed in identical laboratory conditions. Sexual maturity occurs at 2-3 years of age, and the average maximum lifespan for squirrel monkeys is 21 years (14). In early adulthood, at 5 years of age (range=3.7-6.0 years), hippocampal volumes were determined from T1-weighted brain images (Fig.…”

High-Field (9.4T) Magnetic Resonance Imaging in Squirrel Monkey

“…An IV catheter is then placed in the lateral or medial tarsal, metatarsal or saphenous vein, or alternatively in the lateral tail vein (Brady, 2000) using a 24G x 3/4" Surflo catheter with a 27G needle and Surflo injection plug (Terumo Medical Corporation). A small splint is typically used to prevent the ankle from rotating and corrupting the catheter.…”

“…Isoflurane is a recommended anesthetic for use in SM (Brady, 2000), and for maintaining stimulus-evoked fMRI signals (Nair & Duong, 2004;Sicard & Duong, 2005;Liu et al, 2004). Isoflurane is a volatile anesthetic that causes a dose-dependent decrease in blood pressure through vasodilation, though the effect of increasing cerebral blood flow is less than that caused by halothane (Reinstrup et al, 1995).…”

“…Published normative physiological data for anesthetized SM is scarce, and for this reason Table I lists the physiological data (mean, standard deviation) recorded over five typical scan sessions. In the awake restrained SM, body temperature is 37 -39 0 C (Brady, 2000;Pinneo, 1968), mean arterial blood pressure is 140 + 4 mmHg (Byrd & Gonzalez, 1981), and the heart rate may exceed 300 beats per minute (Pinneo, 1968). As Table 1 indicates, isoflurane anesthesia decreases body temperature, blood pressure and heart rate.…”