Far prior to the commencement of academic career, I had already conceived two ultimate
objectives for it. One is to solve the following two problems: How do human beings think? How is
consciousness generated based on human brain? — They have been bothering me since girlhood
meditation. The other, not so much an objective as a lifetime process, is to pass on my knowledge
gained to the next generation.
I am well aware of the complexity and generality of these two problems. In order to eventually
solve them, it seems reasonable and feasible to start from a small point, gradually expanding and
penetrating, approaching the final answers. But where may such point locate? Biological sciences?
— So I chose it as my undergraduate major. Neuroscience? — Thus I intend to further excavate
this field. Nevertheless, the scope is still broad in spite of repeated contractions.
My memory is vague about where and how I obtained the notion that the most important
sensory basis of consciousness must be the visual perception; whereas it was engraved in my mind
and became my primay motivation to join the Vision Research Laboratory directed by Prof.
Hongbo Yu, who had his post-doctoral research done at MIT BCS.
Together with a graduate instructor, I have been working on the project “The Mechanism of the
Sharp Orientation Tuning Property of the Neurons near Pinwheel Centres within Primary Visual
Cortex (V1) of Cat” since February 2012. In a word, we are aimed to label the elaborate
morphologies of neurons near pinwheel centres within cat V1, and elucidate the mechanism of
these neurons’ orientation tuning function based on their morphologies.
To work out this problem, it is a key part to identify the specific locations of pinwheel centres
in V1. Moreover, it was my first and foremost assignment to be faced with. To achieve this goal,
we introduce OGB-1 AM, a membrane-permeable Ca2+ indicator into V1 via in vivo bulk loading,
then observe and record Ca2+ responses of the labeled neurons to visual stimuli via two-photon
Ca2+ imaging. The data obtained would be used to draw orientation maps where there may be
pinwheel centres displayed, around which orientation selectivity of neurons change continuously.
With the pinwheel centres located, it turns to label the elaborate morphologies of nearby
neurons. We should introduce OGB-Dextran, a membrane-impermeable Ca2+ indicator into such
neurons via electroporation; thereby not only neuron populations but also exquisite subcellular
structures such as dendritic spines and axon boutons can be revealed clearly via two-photon Ca2+
imaging. Based on such elaborate morphologies, mechanism of these neurons’ orientation tuning
properties can be elucidated.
Nonetheless, we had to use rats for pre-experiments due to higher price and less convenient
source of experimental cat supply; and it was the very first time in our lab to use in vivo bulk
loading and two-photon imaging in research. I worked with my graduate instructor to try the
above protocol step by step on rats: adjusted the newly-established system of two-photon imaging
and got familiar with the research techniques; gradually explored and accumulated data about
proper experimental conditions; and improved the rate of successful bulk loading. I became quite
skillful in animal surgery and got basically trained in data analysis and techniques of in vivo bulk
loading, electroporation and two-photon imaging.
It is noteworthy that in rat V1, neurons are organized as a salt-and-pepper fashion for their
orientation selectivity; thereby no pinwheel centre exists. Thus, relevant data cannot be collected
via rat experiments. However, once we skillfully handle the protocol, implementing it on cats will
be much easier and more efficient and the expected data can be soon obtained.
This experience has profound influences on my scientific development. Much more important
than the research techniques that I mastered, I acquired a mind, an initially established ideology as
a real neuroscientist. I got a knowledge of reasonable and rigorous researches of systems
neuroscience. Moreover, my advisor Prof. Yu, an alumnus of MIT BCS, demonstrated to me what
a knowledgeable, talented and responsible teacher and researcher would be like; and I am longing
to be one myself. His distinguished and impressive intelligence and qualities primarily originate
from cultivation at MIT. Here initially emerge my motivation and yearning to apply for the
graduate program of MIT BCS.
As I am fascinated with neuroscience, especially what I learned at the Vision Research Lab, I
consciously associate it with studies of other fields of biology. A typical instance is that I modified
the technique of electroporation and applied it to the project of synthetic biology, which was the
principal reason that I joined the Team Fudan-Lux to participated in the International Genetically
Engineered Machine Competition (iGEM) 2012.
I cooperated with a teammate Tian Tian to complete the second of the three projects of our team,
the Project Bacto-Trafficking. After Tian successfully induced nanotubes connecting Hela cells to
form a multi-cellular network and demonstrated their material transportation functions, it turned to
my tasks.
In order to further verify the function of intercellular communication of nanotubes, I observed
and recorded Ca2+ flow through nanotubes among Hela cells via two-photon imaging, and found
that Ca2+ signal transmission via nanotubes did exist between two Hela cells. Moreover, I
introduced GFP-marked E.coli into nanotube-connected Hela cells via modified electroporation,
then observed the transportation and distribution pattern of the bacteria within Hela cell networks
with the help of our team instructor, Dr. Ruoyu Luo. Cultured two days after electroporation, Tian
and I found a specific distribution pattern that a majority of E.coli concentrated in small Hela cells
while few remained in large ones, which was contrary to our expectation. As the smaller cells
were recognized as younger ones, we hypothesized that more active metabolism and fresher
intracellular conditions of younger cells should be great temptations to E.coli despite the space
restrictions. We expected such distribution pattern to offer references to efficient urban planning
of human beings.
The iGEM experience is crucial to me as well. Its particularity lies in its independence, with the
ideas, designs and experiments undertaken almost all by Tian and I ourselves. With little
supervision from academic authorities, I could put my imaginations and designs that seemed crazy
and unreasonable into practice, the achievements of which significantly inspired and enhanced my
enthusiasm and confidence in scientific researches.
As undergraduate research is merely a start of my quest for thoughts and consciousness, I’d like
to get further trained in researching and teaching during graduate studies. I may continue along the
avenue of visual perception within the scope of systems neuroscience; or I will transfer my
concentration to cognitive neuroscience, such as cognitive control, which is considered to be
crucial to the concepts of consciousness and volition. Afterwards, I will move on to the
post-doctoral research, then apply for a faculty’s position, hoping to become a neuroscience
professor one day. Meanwhile, my prospective research field will extend from mere neuroscience
to an organic combination of psychology-neuroscience-philosophy.