Rabies is the only tool for understanding lyssants

Rabies is the only tool for understanding lyssants

We glibly talk about the brain regions and circuits of the rage circuit as givens, but they cannot be effectively studied at the present time.  The risks of working with rabies-infected animals as well as the cruelty of forcing experimental subjects to experience the lethal effects of rabies infection render this approach unacceptable.  We must, instead, be able to work with the native target for the virus, able to turn on, and off, the effects that the virus would produce, without the fear of actual infection and death. 

Early on in the study of animal psychology investigators stimulated various regions of the brain to see what would result.  In some cases they induced behaviors, in cats especially, that had characteristics of attack or of defensive rage.  However, without an object to fully express these behaviors upon, it was difficult to say what was being produced; aggression, defense, rage, or simply a collection of muscle movements.  In light of the uncertainty of what these collections of behaviors meant, they were termed “sham rage” and investigation of them stopped. 

Another tool that held promise was a result of damaging a brain region known as the septal nucleus, an area in the heart of the rage circuit.  Damage to this area sometimes produced a syndrome very much like furious rabies where sudden noises or movements would result in a sudden, full-blown attack on whatever happened to be near.  I can personally vouch that the attack rabbit from Monty Python and the Holy Grail is no fiction!  The speed and ferocity of a raging rabbit flying out of its cage and aiming itself directly at one’s throat is terrifying.  Unfortunately, for our understanding of the basis of rage, this syndrome disappears fairly quickly after the septal area is damaged and is therefore not useful for study. 

Some instances of human rage, like that of Charles Whitman’s murder spree from the University of Texas Tower, can be traced to specific trauma to the brain; in his case a tumor pushing on another structure in the rage circuit called the amygdala.  However, most lyssants, like animals infected with rabies, show no signs of structural damage in the brain.  We know that the amygdala is activated during very stressful events, like those that result in PTSD (post-traumatic stress disorder).  This activation appears to be necessary for making the emotional memories so strong.  We can presume that this type of activation of the amygdala is important for the amazing feats of strength, etc. that can occur in emotional situations.  On the other hand the amygdala is largely absent in some people.  These people do not feel fear.  The understand that certain situations are dangerous, but they do not express fear in the situation.  They don’t exhibit lyssantic behaviors.  We can expect that pharmacological manipulation of the amygdala or brain regions connected with it will allow us to induce rage.  However, this hasn’t occurred yet, strongly suggesting that the critical neuronal circuits, the critical neurotransmitter receptors, are not known.  But we do know that rabies virus, its targeting motif, can produce rage behaviors, so we can presume that it is affecting the critical receptors. 

Experimental neurobiologists have also studied aggressive behavior, but aggression by itself overlaps only partially with rage.  Even the studies of aggressive behavior have had limited success, in large part because we did not/do not have pharmacological tools to selectively stimulate and block all the subtypes of serotonin receptors that appear to be the most promising underlying mechanisms.  Even when these tools do become available, it is already clear that aggressive behavior is quite different from rabidity.  Aggressive behavior, bullying is one aspect, has a large component of voluntary control with positive reinforcement of past occurrences that lead an individual to continue to use these behaviors.  On the other hand one of the hallmarks of lyssantic behavior is that it does not appear to care whether it is likely to result in a win or a loss, it just rages.  Of course, we presume that lyssantic behavior has been successful in keeping individuals alive and therefore has been kept as an important part of our genetic heritage.  I expect it is possible for people to learn the triggers that can release a lyssant’s rage, but there is still a large difference from aggressive pushiness and impulsive aggression.  Reports about the changes in demeanor of people like Al Capone going beyond their being aggressive to becoming a ‘monster’ with a baseball bat are probably good examples of lyssantic behavior in action.

Our most promising avenue to pursue understanding lyssants and their behavior is still the rabies virus.  However, as long as we have only the lethal virus itself, we will be unable to fulfill our need to understand rage.  We must, and we have the tools to do this, discover the target of the rabies virus; the only psychologically important part of the virus.  Being a virus has largely distracted us from learning the secrets it holds to our own inner selves.  The behaviors it unlocks in its victims are not the result of it being a virus, only its targeting motif is necessary to produce these behaviors.  So, we need to discover the target.  And, as a major added bonus, discovering the target, the CNS receptor, will also provide us the means to discover post-infection treatments for rabies itself.  It’s a win-win-WIN BIG situation.