Macross Frontier- Vajra and the second brain

Macross Frontier- The Vajra and the Second Brain


Ok, first off, the second brain is not the brain you are thinking of, and this is a topic that I didn’t think I would ever get to approach, but science is always discovering new things. What I am talking about is how the Vajra, humans, and the V-type virus are all connects, including how some aspects of their physiology might work.vajra virus

FYI- This is a bit of a misnomer, because it is described as a microorganism of some kind, but it is referred to as a virus, which is not a living thing. Viruses are not considered living things because they do not meet all of the requirements needed to be considered a living thing. The crucial factor that is missing is that viruses do not have a cell membrane and cannot perform the requirements for life on its own. Viruses can only reproduce inside other cells. Naming aside it is safe to assume that the “V-type virus” is actually a bacterium since that is what it is treated as in Macross Frontier.


Symbiosis is the term used to describe two organisms (of different species) living in close relationship where both organisms routinely interact. There are three types of symbiosis:

Mutualism- Both organisms benefit
clown fish
Commensalism- One organism benefits, and one is not harmed


Parasitism- One organism benefits and one is harmed

In the case of the Vajra I will be talking about mutualism between the Vajra, and the V-type virus (bacteria). The Vajra are giant space faring insect-like creatures who provide a home and nourishment for the V-type bacteria, while the V-type bacteria give the Vajra a way to communicate across long distances. While the biology or the organisms is certainly fictional, the idea of an insect and a microorganism having a mutualistic relationship is not. As all of you probably know, termites eat wood, but what you probably did not know is that termites can’t digest the wood that they eat. It turns out that several microorganisms (bacteria, archaea, protists) living in the digestive system of the termite break down the wood fibers. The microorganisms digest the wood fibers and release vinegar, which the termite then uses for energy. In this system the microorganisms gain food and a safe place to live, while the termite gains the ability to feed on a food source not many other animals do.

There is also an example of a microorganism changing another animal’s behavior, but sadly this is a parasitic relationship. Toxoplasmosis is a parasitic protist that lives in mice but reproduces in cats. Toxoplasmosis alters the behavior of infected mice, causing them to not be afraid of a cat’s scent, and instead be attracted to the scent of cat urine. This of course makes the mice more likely to be eaten delivering the Toxoplasmosis to the cat where it can reproduce. One study did find correlation between changes in human behavior and toxoplasmosis infections, but no causation for such changes exists at the present time.

Bacteria and the Brain

The symbiosis angle was great, but the V-type virus is heavily implied to affect how the Vajra thinks and acts, which is beyond what microorganisms can do. Now many of you might be thinking that this is where I am going to call it busted…. Well, about that- new medical research has started to show that changes in the bacteria in the human digestive system can influence brain activity.

Hepatic encephalopathy- There is a decline in brain function due to liver disease that improved by taking antibiotics that affect gut bacteria.

Autism- studies have shown that children with autism have a less diverse population of gut bacteria.

Animal studies- Mice bred to have no gut bacteria had significantly different levels of neuroactive compounds.

Bacteria- Recent studies have shown that some bacteria can produce neuroactive compounds that can be absorbed by the body.

Stress and Anxiety- Some recent studies have also started to show that changes in your gut bacteria can influence stress and anxiety. I think this happened to me while living in Mongolia for three years.

So, while there is no definitive proof yet that bacteria can directly influence the brain, there is compelling evidence that gut bacteria and the brain are connected.

Do the V-type Bacteria live in the gut?

While Macross Frontier does take a while to get around to it, we do eventually learn that the V-type bacteria live in the gut of the Vajra.


This is somewhat important because the V-type bacteria are quite infectious to humans/zentradi, except for Ranka. Macross Frontier makes it clear that a V-type infection is treatable in early stages, but if left alone, it will migrate to the central nervous system (brain and spinal cord) at which point it is fatal. What makes Ranka different is that her V-type infection is located in her digestive system and is not migrating to her brain and spinal cord. In fact, outside of her connection to the Vajra Ranka’s V-type infection, it doesn’t bother her at all.

Why is that V-type microorganisms in the gut (like Ranka), are harmless, while the same microorganisms in the brain (like Sheryl), are deadly? It’s the same microorganism, so why is it that it has vastly different effects in two locations? This is actually based on real science, and the best example is the bacteria Escherichia coli. Escherichia coli, or E. Coli, lives rather harmlessly in our digestive tract and this is a normal part of our physiology. However, if E. Coli ends up outside of our digestive tract, it can cause urinary tract infections, skin infections, and pneumonia, to name a few.

Ranka’s infection– the pink glow in her stomach
Sheryl’s Infection- the pink glow in her head

Vajra do not have a brain

Macross Frontier explains on several occasions that the Vajra do not have a brain, with Ranka stating that the Vajra sing with their stomachs. However, that is not entirely correct. Excluding the sponge (yes, it is an animal), every known animal has some sort of nervous system. While it might not include a formal brain structure like we see in vertebrates, they all have a system to control their own bodies. In some cases, it can be a connection of nerve cells known as a ganglion. A ganglion can act as a relay point in the nervous system, and it can exert control on the body structures surrounding it. In some animals their nervous system is just a cluster of ganglia (plexus). In fact, our digestive system has a number of ganglia controlling it.

New research has shown that the ganglia in and around our digestive system have their own unique neural patterns (brain waves), hence the term second brain. In fact, the nerves of the digestive system release 95% of the body’s serotonin and 50% of its dopamine. This area of study is still young and falls into what I feel is best described as we know something is happening, but we’re not sure what it is yet.

So yes, the Vajra do have a brain but it’s just located around its gut, and has a symbiotic relationship with the V-type microorganisms. This is why Alto was able to destroy the head of the Vajra queen and not kill her.


It also explains why Sheryl’s V-type infection spread to her brain. The V-type microorganisms were looking for the nervous tissue they normally live in close proximity with, and the bulk of our nervous system is located in our brain and spinal cord, and not the gut like it is in the Vajra.


Removing the clearly fantastical elements such as the giant telepathic space-faring alien insects and their space bacteria how did Macross Frontier do?
1- Microorganisms being harmless in one location of the body and harmful in the other- confirmed
2- Microorganisms influencing the behavior of an organism- plausible
3– A complex animal not having a brain- busted
4- A complex animal having a brain in their gut- plausible
5– An animal and a microorganism having a symbiotic relationship- confirmed
In the end I am going to call the biological connection and behavior of the Vajra and the V-type virus in Macross Frontier plausible.



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