0 comments on “Design, Naturally: Wasps take the sting out of brain surgery”

Design, Naturally: Wasps take the sting out of brain surgery

By Anwen Bowers

‚ÄúI cannot persuade myself that a beneficent & omnipotent God would have designedly created the Ichneumonid√¶ with the express intention of their feeding within the living bodies of caterpillars ‚Ķ‚ÄĚ

This statement from Darwin is often quoted in discussions about his changing relationship with religion as he developed his theory of evolution. 150 years later, the ichneumonidae in question are taking a step towards shedding their demonic reputation by inspiring a new approach to neurosurgery.

| Image: Sean McCann
Pretty deadly. We could look at ichneumonidae ALL DAY.| Image: Sean McCann

The ichneumonidae are a subfamily in possibly the largest group of animals in the world ‚Äď the parasitoid wasps. Estimates of the total number of ichneumonidae species alone reach up to 100,000 ‚Äď more than all the vertebrate species in the world. The wasps gain their name because they¬†brutally kill their host species, as opposed to parasites which drain the resources of an organism without causing significant harm.¬†Indeed, life histories of the parasitoid wasps are close to the stuff of nightmares.

The extremely high diversity of ichneumonidae has arisen because each species of wasp has evolved to target just a single type of prey, and to do it as efficiently as possible. Each species is distinguished by its specialised weaponry or tactics that allow them to tackle their prey in their niche habitat or lifestyle. For example, Lasiochalcidia igiliensis’ chosen host is the antlion larva, a ferocious predator in its own right with vicious jaws that it uses against a range of arthropod prey, even spiders.

antlionlarva
A badass Antlion larva clearly has only one thing to fear. Fear of L. igiliensis itself. | Image: Larah McElroy

The seemingly fearless L. igiliensis has been observed to bait the antlion larva, encouraging it to attack the wasps itself. At the point of attack, the wasp will use its powerful legs to prise the jaws of the antlion open, whilst simultaneously depositing an egg into the antlion larvae’s throat. There the egg will incubate, feeding on the antlion from the inside, until the time for metamorphosis comes. At this point the wasp will burst out from the antlion, not unlike the infamous scene from Alien.

Strategies in other species include a fibrous mesh that traps air allowing the wasps to dive down and reach caddis fly in their underwater habitat, and a hormone invisibility cloak that allows the wasps to live within an ants nest, even up to adulthood, without detection. These guys are the Q Branch of the insect world.

M. macrurus prepares to drill. | Image: Evan Kean
M. macrurus prepares to drill. Just look at that ovipositor. Stunning, and inspiring… | Image: Evan Kean

Here at Rising Ape we can vouch from experience that great ideas happen when you put a bunch of scientists from different backgrounds in a room, and maybe give them a bottle of wine. This seems to be what happened in the case of Dr Ferdinando Rodriguez y Baena, a medical engineer who found himself inspired by a serendipitous dinner party conversation with zoologist and biomimetics expert Julian Vincent.

Vincent described how the parasitoid wasp species Megarhyssa macrurus, is able to use her egg laying tube to drill down into tree bark, where she deposits her eggs onto the larvae of the pidgeon tremaz horntail (how did this come up as a topic?! Over dessert?). This is possible thanks to a complex structure of three tubes that can bend and flex as the wasp drills, allowing her to position her eggs with pinpoint precision.

needlepic_imperial
The three parts of this needle echo the ovipositor of the drilling wasp and give it unparalleled flexibility. | Image: UCL

This elegantly specialised structure gave Baena the idea for a new style of needle that mimics the ovipositor. The design allows surgeons to control and manoeuvre the needle inside the patient, navigating around sensitive and fragile parts of the brain. This minimally invasive surgical procedure could even allow surgeons to deliver drugs to very specific areas in the brain, potentially treating diseases such as brain tumours and Parkinson’s. By saving lives for a change, the ingenious ichneumonidae wasps could be about to improve their reputation.  Who knows, even Darwin may have approved.

0 comments on “Memory Makers in the Planetarium”

Memory Makers in the Planetarium

real-brain_0

On 27th September, Rising Ape enters the At-Bristol Planetarium dome to bring you a unique journey into a truly mysterious world: Your own brain.

In partnership with Fayju Games and the University of Bath, Memory Makers will be an evening of unlikely experiences inside your mind. Come along to find out how much your brain can really remember, how easily it can be fooled, and how local researchers are trying to better understand and treat dementia.

memorymakerscascadeYou can buy tickets for one of two sessions on the night. Find out more on the At-Bristol event page.

Taking in jelly brain dissections, competitive memory games, and an exhilarating 3D preview¬†of upcoming VR game Cascade, developed in collaboration with neuroscientists — plus a bar and the classic At-Bristol exhibits. Altogether, the evening promises to be a night you’ll definitely want to remember.

This event is funded by the Biochemical Society.

0 comments on “S is for Simple Rules”

S is for Simple Rules

By Jonathan Farrow from the Thoughtful Pharaoh

Consider the following: schooling fish, roundabouts, segregation, and human consciousness are all examples of the same fundamental property of the world.  It may seem crazy to suggest that roundabouts may be interesting in some sense, but bear with me.

The property in question, and this week’s topic, is emergence. ¬†In each case individual entities, by following simple rules, can create complex patterns of behaviour. ¬†What makes these patterns special is that they can’t be predicted based on the simple rules alone.

Swarms

If you’ve ever seen a murmuration of starlings, you have probably found yourself wondering how that many birds (upwards of 100,000) can all fly so quickly in such close proximity without hitting each other. ¬†For those of you uninterested in ornithology (the study of birds), there are also plenty of examples of swarms in entomology (the study of insects) and ichthyology (the study of fish), and even¬†chiropterology (study of bats).

Image by SteveD
Image by SteveD

In each case, the animals are unaware (and frankly, uncaring) of the beautiful shapes their swarms make. ¬†They aren’t even trying to swarm. ¬†They are trying to survive and their instinct tells them to follow a few simple rules. ¬†Since the advent of computers, scientists have been trying to find out what those rules are.

One of the most famous computational models of swarming behaviour was proposed by Craig Reynolds in 1986.  In his Boids program, simulated birds had to follow three rules:

  1. Separation:¬†Don’t crash (steer away from nearby boids).
  2. Alignment: Get with the program (steer towards the average heading of nearby boids)
  3. Cohesion:¬†Don’t get lost (steer towards the average location of nearby boids)

This model is actually a really good model for the behaviour we observe in birds and fish.  Recent studies have also shown this alignment rule is especially important for bats.

Locusts, on the other hand, seem to have a much simpler set of rules.  Locusts just want to avoid getting their backsides eaten.  When approached from behind, locusts will tend to fly forward for fear of cannibalism.  This creates an overall tendency to move forward and can lead to giant swarms.

Image by CSIRO
Image by CSIRO

Roundabouts

If you’ve ever been to Swindon (and, from what I hear, you’re not missing much if you haven’t), you might have come across quite possibly the most offensive piece of civil engineering in the UK.

That's right.  A giant roundabout.  Image in the public domain
That’s right. A giant roundabout. Image in the public domain

As a North American, I cringe at the thought of even a tiny roundabout but Swindonians apparently hate everything that is good in this world.

They built the Magic Roundabout. ¬†A terrifying series of 6 small roundabouts encircling a larger roundabout that goes the other way. ¬†If that sounds confusing, it’s because it is.

The more confusing part, however, is that hundreds of thousands of cars pass through it unscathed.  While there is certainly a lot of anxiety about it, there have been only 14 major accidents in 25 years.

Hell for North Americans.  Image from the BBC
Hell for North Americans. Image from the BBC

The vast majority of people pass through fine, despite there being 5 different entry and exit points and many conflict points (places where streams of traffic cross).  This happens because of a few simple rules:

  1. Follow the lines
  2. Give way to cars coming from the right
  3. Drive to where you want to go
  4. Don’t crash

Apparently it’s actually an effective way to move cars through an intersection, but my North American sensibilities just can’t handle it.

For more information on this piece of crazy road engineering, visit this explanatory page and watch this video.

Segregation

Choosing¬†who you associate with based on a singular trait has been known to lead to a lot of issues in the past. ¬†As a dog person, I’ve lost a lot of friends to cats (and their parasites). ¬†Despite my friendly demeanour and my ability to put up with a fairly large proportion of cat-lovers in my immediate vicinity, at a certain point I start to feel uncomfortable and want more fellow dog-lovers.

Tensions flare.  Image by Peretz Partensky
Tensions flare. Image by Peretz Partensky

In 1971, Thomas Schelling set out to model this behaviour and came out with a somewhat surprising and scary result. ¬†Even when people are fine with being in the minority, if they are dissatisfied when surrounded by a large majority of “others”, they will tend towards segregation. ¬†The model followed a few simple¬†rules:

  1. If you are surrounded by a certain percentage (e.g. 30%) of similar people, you are satisfied
  2. If you are surrounded by a certain percentage of different people (e.g. 70%), you are dissatisfied
  3. If you are dissatisfied, move to somewhere where you are satisfied.

Within a few rounds, there is very little diversity left as people¬†tend to move towards those who are similar. ¬†This, despite the fact that no individual is saying they outright dislike the other group or couldn’t live with members of the¬†other group. ¬†This model helps to explain why segregation is so hard to eliminate.

Interestingly, this tendency towards segregation can be reversed if a maximum of similar people rule is added:

4. If you are surrounded by a certain percentage of similar people (e.g. 90%) you are dissatisfied

Again, complex patterns and simple rules.

To learn more about the model, go here.

Conciousness

There are approximately 100 billion neurons in an adult human brain.  These neurons are connected in intricate ways to create an estimated 100 trillion connections.

Now that's a lot of connections!  Image from Wikimedia
Now that’s an impressive set of connections! Image from Wikimedia

Somehow (and to be honest we’re not really sure how yet), these connections lead to all of our brains’ activities from thought to imagination and¬†memory. ¬†The abilities of the system (the brain) couldn’t possibly be known from the rules that neurons abide by. ¬†All that a neuron does is pass on its signal according to a set of rules. ¬†We still don’t know what those rules are.

We do know that when a neuron is activated (whether by electrical or chemical stimulation), it activates other neurons.  The precise number and location of these other neurons is still a big mystery in neuroscience, but it must be activating both nearby neurons and neurons on the other side of the brain.  This dual activation of long- and short-distance connections is what creates the sustained patterns we observe in fMRI scans.

Human Connectome Project
The¬†Human Connectome Project, kind of like the Human Genome Project before it, is setting out to map all of the brain’s 100 trillion connections to better understand how it works. ¬†Image by Xavier Gigandet et al.

While I don’t mean to suggest that everything in life can be boiled down to simple rules, I think it’s pretty incredible the patterns¬†that emerge from individual actors all playing their parts.