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Sulawesi is a small island in the Indonesian archipelago. Its geographic location makes it a hotbed of biodiversity, and it is home to species not found anywhere else on the planet. Many biologists have looked there to solve some of the mysteries of evolution, including McMaster’s Ben Evans.
“I’ve been interested in evolutionary processes in general and this has been an arena to explore things like how species disperse across marine barriers, how they compete with one another when they arrive in a novel habitat, and how adaptation occurs and what it depends on,” said Evans, whose work over the last 15 years has focused on endemic primate and frog species exclusive to Sulawesi.
The species garnering the most attention is the fanged frog, which Evans explained has been divided into subspecies based on body size. The larger frogs are found in fast-flowing water, while small frogs are found on land. These smaller frogs spend more time on land than in water, and have undergone a unique adaptation that Evans and his colleagues believe has occurred to combat predation.
Most frogs reproduce by laying eggs that are externally fertilized. One species of fanged frogs, however, gives birth to live tadpoles, while another lays eggs with jelly coats on leaves. Evans finds these discoveries fascinating, but he claims it is not the most interesting aspect of this adaptation.
“I think the more important message offered by this new species is that there’s a lot of diversity we don’t even know about and therefore that there’s a lot more research to be done,” he explained.
The unique reproduction of fanged frogs has been compared to that of placental and marsupial mammals.
“If you look at it coarsely, it’s quite similar in that internal fertilization and internal gestation in mammals is advantageous because it increases offspring survival,” Evans said.
However, there are still important distinctions to make between the two groups. The phenomenon of fanged frogs giving birth to live young has evolved separately from mammals’ ability to reproduce in the same way.
“It uses a distinct set of genetic tools and probably someway comparable to mammals but it’s an independent evolution of a similar characteristic,” Evans explained.
He added that a female fanged frog has been observed giving birth in standing water already containing tadpoles. He admits it cannot be confirmed yet whether or not the tadpoles came from the same female, though he believes it is unlikely.
“It’s probably the case that she doesn’t provision the tadpoles, so she doesn’t come and bring them food like a mammal would.”
This discovery opens many doors in the fields of evolutionary biology and genetics. Evans discussed his desire to better understand the specific details of how female fanged frogs are able to give birth to live tadpoles as well as the larger scale of species diversity on Sulawesi.
“That’s going to involve field work, genetic work, it’s going to involve careful ecological studies and comparison to other species of frogs, and even other vertebrates.”
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The annual State of the Academy address is meant to be an opportunity for the Provost’s office to share information with the rest of the university on the school’s progress over the year. But this time, it was supposed to be different.
The 2012 State of the Academy was promoted for its “new format,” a conversation between university administrators and the greater campus community, rather than a speech. According to current Provost David Wilkinson, it was meant to “engage [McMaster] in a cross-campus dialogue.”
Convocation Hall, equipped with two audience microphones, reflected this change. Wilkinson and university president Patrick Deane, who joined him for the presentation, were seated comfortably in armchairs at the front of the room.
In elaborating on talking points offered by moderator Gord Arbeau, Director of Public and Community Relations, the two administrators made it clear that their impression of McMaster’s current situation was positive.
“When you look at the [McMaster University Factbook], what it would show you is that…as an institution we’re doing very well in difficult times,” said Wilkinson.
“There are lots of great things going on, lots of challenges, but the future really looks rosy at McMaster.”
Although a variety of topics were offered for discussion, the speeches from both Deane and Wilkinson circled back to “Forward with Integrity,” the president’s 2011 letter that offered a set of guiding principles for McMaster as it moves forward.
The emphasis of the presentation, in conjunction with “Forward with Integrity,” was to “rephrase” the goals of McMaster, and to reemphasize the “research-focused, student-centred” nature of Mac.
“We’re at a phase in laying out our sense of the institution’s future in which we need to build on what has been strong historically here and that very close connection between teaching and research, which is part of the Mac culture [and] has been since the beginning,” Deane explained. The president was intent on underlining McMaster’s reputation, reaffirming that “we are an institution devoted to learning through inquiry and discovery.” He encouraged students and faculty to “bring...[the] power of the critical and inquiring mind.”
It was broader ideas like these that made up the bulk of the presentation.
In addition to the university’s culture, Deane and Wilkinson also touched on such initiatives as the “learning portfolio,” a new emphasis on experiential education that was encouraged by “Forward with Integrity.”
“[We want] students [to] actually have a portfolio of experiences that extends beyond what shows up on their transcripts,” said Wilkinson.
The most controversial topic of discussion was the internationalization of McMaster, something the president has admitted to not always being comfortable with.
“I am very much averse to what I regard as an exploitative model of higher internationalized higher education,” Deane said, elaborating further to say that he is “not persuaded, either in terms of the long-term benefits or the ethical compulsions of this model which basically sees the world as a market to be drawn on to subsidize our current operations.”
International students now make up roughly five per cent of McMaster’s student body. The recruitment of these students is seen by many universities to be an economic benefit because of the hefty additional fees they pay. Deane emphasized that true internationalization would involve “being changed by the students who are invited to come here.”
It seemed that the audience, made up primarily of faculty and staff, with only a small representation of students, was not moved by this, or any other topics. When the floor was opened to questions, no one in the audience stepped up. Despite the insistence on dialogue, the new townhall format did not result in the high amount of audience participation that was initially envisioned.
The exam is sitting in front of you, mocking you. The blank spaces under the questions are cavernous, the scantron bubbles are – unlike your understanding – crystal clear, and when you look at your Casio, all the screen displays is “666” because you can’t remember a damned thing. But why not? Isn’t memory just like a computer’s desktop? Files stored neatly, right where you put them when you listened in lecture? This is a common misconception of memory.
As with many other common ideas of complex functions, the impression of memory is largely flawed.
Researchers like Terje Lømo, Gary Lynch and most recently Dr. Todd Sacktor, professor of physiology, pharmacology and neurology at the State University of New York, are unveiling what actually makes our memories along with how they stick and how to strengthen, and erase, everything you’ve ever stored in your mind.
Reconsolidation
Many people imagine memory to be a storage space, almost like a file cabinet, where you can go, look at whatever you need at that particular time, and then put it back in its place and leave it as it always was. We’ll call this File Memory. Not to say this doesn’t happen sometimes, but File Memory isn’t a complete explanation of how we remember.
Reconsolidation, a distinct process that maintains, modifies or consolidates memories, was first observed as early as 1968, and in recent years is beginning to be more complexly understood.
During reconsolidation, memories are actually moved out of long-term memory while you’re using it, thinking about it, or talking about it. They are then resaved again.
To liken it to the file cabinet analogy: when the memory is recalled, the file cabinet is destroyed, and the file is sent up for use, so you can alter it, strengthen it, and update it before it goes back. Then, when the memory is stored again, another file cabinet is built to hold it. But, this file cabinet may not be made the exact same way. It could be stronger, more complex, larger, and will be somewhat a little different than the last one.
Todd Sacktor, professor at the State University of New York, says of reconsolidation, “the whole idea of reconsolidation is that it both strengthens old memories – because it gets used again – and it updates the memories with new information.”
That’s why reading your notes the same day you took them can be so useful: you have an initial memory – you remember taking the notes and in what context they were taken - that you take out, build on, and reinforce before storing it again, this time more complexly and permanently.
Protein kinase M zeta (PKMzeta)
Even though the “File Memory” concept is largely inaccurate, we can find some similarities human memory has to that of a computer’s. In a computer, memory is stored through combinations of 0s and 1s. Though the information it stores is complex, it is constructed by those two basic blocks. This can also be compared to human genetics: DNA codes our entire genetic structure while itself being made up by four distinct chemicals.
Memory too, for all its complexity, is stored by one very basic building block: protein kinase M zeta, also known as PKMzeta. PKMzeta is what builds and keeps all types of memories in long-term storage, all over the brain.
With the presence of more of the enzyme, the result is stronger memories. This being said, conversely less of this enzyme means weaker, or no, memories.
The most well-known and illustrative proof of this resulted from a study by Sacktor, in partnership with the Israel Weizmann Institute of Science. The experiment consisted of having rats associate the action of intaking sugar water with discomfort, and then breaking them into three groups: one where PKMzeta was inhibited, one where PKMzeta was made to overexpress, and one control group.
A drug called zeta inhibitory peptide – ZIP – was administered to wipe the rats’ memory in the first group. ZIP does not even require the memory to be in the process of reconsolidation for it to work. Dr. Sacktor says of this “inhibiting PKMζ is like dissembling all one’s file cabinets, regardless of whether they are opened or not. After the drug has worn off, the pieces do not reassemble.” This was definitely observed in the experiment, and the rats were no longer wary of the sugar water.
In the group where PKMzeta was made to overexpress itself, the rats were even more afraid of the sugar-water than the control group. This phenomenon surprised Dr. Sacktor: “If you had a computer hard-disk and the 1 is the PKMzeta and the absence of PKMzeta is the 0, and then you randomly throw in a whole bunch of 1s into the hard-disk,” which is effectively what adding PKMzeta would do, “you’re going to degrade the information, just as you would by throwing in a whole bunch of 0s. But somehow if you throw some in – not a huge amount of 1s – there’s some aspect of the memory in which the 1s tend to go where the other 1s are, and then that makes the memory stronger. But it’s still pretty mysterious.”
Applications
As with most major scientific developments, the ability to wield the newfound knowledge often emerges much later, after the discovery.
“Once you understand the storage of information - even though it may take a couple of decades for that to change things – everything gets changed,” says Dr. Sacktor. “For example, when they figured out in 1955 the structure of DNA and convinced everyone that that was the genetic information, you could ask the same question ‘what difference does it make that we know that DNA is why some people’s eyes are blue and some people’s eyes are brown? We kind of knew that from Mendelian genetics anyway!’ It took decades before it actually made much of a difference for medicine.
I can’t predict what the real implications [of PKMzeta] are going to be. But it’s going to be something big.”
Already there is recognition of how many major applications this discovery could yield. Mild reconsolidation blockades have already been tested on subjects suffering from Post Traumatic Stress Disorder, results showing promise for the future of this technology.
Other applications could include helping addicts successfully kick their habit, healing some pain caused by central neuropathic pain syndrome (pain that is still felt, even after physical healing) and perhaps slow or stop the progress of degenerative diseases like dementia and Alzheimer’s.
It is clear that this development will lead us in the future of understanding and manipulating memory.
Dr. Sacktor puts it plainly when he says “I suspect the 2000s - this 10-15 year period - are going to be a golden age for understanding long-term memory.”
We won’t soon forget this groundbreaking discovery.
