The rest of the story

I believe that when a public institution elects to employ animals in research, it should be willing to explain and defend its decisions out loud.  Sometimes animal activists make the job easy, by grossly misrepresenting the design, consequences, and/or reasons for a study.

This is true about certain recent attacks against animal research at UW-Madison.  Our Institutional Animal Care and Use Committees recently approved a proposal to subject 20 rhesus monkeys to “peer-rearing”, a form of early life stress.  Here’s what the Animal Legal Defense Fund (ALDF) has to say about this experiment’s design and consequences.

“Infant monkeys are immediately removed from their mothers after birth and kept in total isolation.  They will be given ‘surrogate’ materials known to provoke heightened anxieties.  For 42 days, the confused monkeys will be subjected to relentless fear and panic-inducing tests while totally isolated.  These tests include being intentionally terrified by human researchers, being left alone with a live King snake, and being left alone in a strange room with a strange monkey.”  Later, they add: “These tests will cause serious psychological torment to baby monkeys.”

They did get one half of one sentence right.  Infant monkeys will be removed from their mothers.  After that, it’s all wrong.  The monkeys are not kept in total isolation.  They are reared in a human-style baby incubator by people who feed and otherwise care for these infants until they have grown enough to regulate their own body temperature.  Once that happens (at 3 to 6 weeks of age), they are permanently paired with another young rhesus.  During their stay in the isolator, the “surrogate” materials they receive are known to actually REDUCE anxiety.  I’ll also note that this same approach is taken to rearing baby rhesus monkeys whose mothers reject them at birth and who are not adopted by a foster mother.  In other words, sometimes peer-rearing is used to save a baby monkey’s life.

The monkeys are not subjected to “relentless fear”.  Instead, approximately once a month for up to 18 months their reaction to a novel situation is observed.  What are these novel situations?  An unfamiliar human stands in front of their cage.  An unfamiliar monkey is housed in an adjoining cage, or the two are housed together in a play cage.  And one time, the monkey can see a snake, closed within a solid glass aquarium that sits outside the monkey’s cage.  That does not constitute relentless fear.

What about the “serious psychological torment” claimed by ALDF?  UW-Madison colony records of peer-reared monkeys spontaneously rejected by their mothers indicate that, typically, they respond to novel situations by increased thumb sucking, not by increased self-injury, compared to monkeys raised by their mothers. From 2002 to present, only one peer-reared monkey injured herself within the first 18 months of life.  She now no longer exhibits this behavior, and currently is raising an offspring of her own.

In previous studies, these UW-Madison researchers mapped out pathways in the brain that are overactive in anxious monkeys (it turns out the same pathways are overactive in anxious humans too).  They identified which parts of the brain are altered when predisposition to anxiety is inherited, which are altered when anxiety is caused by adversity in early life, and how genetic vulnerability and environment interact.  These discoveries demonstrate the benefit of the past use of monkeys in this laboratory.

So what, then, is the reason for the current studies?  The point of these studies is to identify changes in brain chemistry and gene expression in those overactive areas of the brain that accompany anxiety caused by early adversity. This knowledge can provide new specific candidate chemical and genetic targets for potential therapies. It builds on the earlier findings, and could not be obtained by a different experimental approach.

Anxiety disorders affect millions of people in the United States, and the mechanisms of this disease are similar between humans and rhesus monkeys.  Early adversity is the most important determinant of later development of anxiety and depression.  Current treatments are only marginally effective.  As for any study involving animals, we each need to decide for ourselves if using 20 monkeys in the experimental approach described above is balanced by the potential benefits of this research.