Exploring Xu's World
Xu's Motto:
-
No pain, no gain.
-
Do a thing, do it well.
Name: Xiangmin Xu Sex: male Nationality: Chinese
Date of Birth: Oct., 72 Place of Birth: Zhejiang, China
Mailing Add: Dept. of Psychology, Wilson Hall 301,
Vanderbilt University, Nashville, TN 37240
Email: xiangmin.xu@mcmail.vanderbilt.edu / xiangmin.xu@vanderbilt.edu
Phone: (615)322-2694(Lab) (615)383-8068 (H)
Go
Back to Main Page
EDUCATION
-
7/1998-Present Vanderbilt University
PhD in Psychology Program (Neuroscience Area)
-
9/1995-6/1998 Shanghai Institute of Physiology, Chinese Academy of Sciences
MS
-
9/1990-7/1995 Shanghai Medical University
Bachelor of Medicine (equivalent to MD training)
My
EXPERIENCE
I was born in a caring and harmonious
family. My parents brought me up in a good way and I had a good time in
childhood.
After completing my high
school in 1990, I was encouraged to study medicine. I entered Shanghai
Medical University(SMU) and spent five years there to get my medical
degree. I grew mature in college and my life then was fun. I was an active
student in SMU, and was involved with many student organizations. To mention
it, I organized and chaired the SMU Society of Wu-Shu Sports in 1992-1994,
which eventually grew into one of the two largest student associations
in SMU and now still enjoys much popularity in the university. However,
I am happy that my extracurricular activities didn't bring much trade-off
to my academic pursuit. When graduation came near, I chose for further
education and turned to basic research.
Then during 9/1995-5/1998,
I was enrolled in the Neurosceince Progam with the supervision of Dr. Xiong-Li
Yang at Shanghai Institute of Physiology,
CAS. Dr.Yang's group is quite strong in the retinal neuronal circuitry
research by using such techniques as the whole-cell patch clamping on isolated
cells, patch clamping on retinal slice and intracellular recording for
intact retinas as well as morphological means. My project then was particularly
to study the modulation of the transmitter glycine on the carp outer-retina
neurons. I got some interesting and important findings. (Please refer to
the abstracts of my MS thesis and the paper in
publication.) In the institute life was hard but rewarding. I grew stronger
and learned to be patient, self-motivated and optimistic in some difficult
situations. I could develop some ability for research work and know how
to tackle research questions. Moreover, I cherished valuable friendship
with some guys over there.
I came to Vanderbilt University
in July, 1998 and have been trying hard to do well in my study and work
here. So far I love living here.
It should be challenging
but exciting for me to work as a TA in the Department of Psychology. I
have worked as a TA to Dr. McNamara in his PSY 101 class of last semester,
which is a good experience. Through interaction with students, other TAs
and professors, I got to undertand better the culture and the univeristy.
It also helped me to improve my English and teaching skills.
This semester I work for
Dr. Ray as a TA in his PSY 101 class. Welcome to the class
webpage.
RESEARCH
WORK
When I was at Shanghai Institute of Physiology,
CAS, I did some retinal research. Please refer to the abstracts
of
my MS thesis and the paper in publication.
Now I work in the lab of Dr.Vivien
Casagrande and do research on the physiology of the third visual pathway
(K pathway). Please see my
research proposal and a recent Neuroscience
Meeting abstract.
MY PREVIOUS WORK
Glycine modulates neuronal activities in carp
outer retina
-
Thesis Abstract
Glycine is a major inhibitory transmitter in the retina. A lot of
work has indicated that glycine play important roles in modulating signal
transmission in the retina. In the present work we investigated the effects
of glycine on ERG and retinal neurons, using ERG recording and microelectrode
intracellular recording techniques in the isolated, superfused carp retina.
Our main results are as fellows: (1) 4 mmol/L glycine clearly suppressed
dark-adapted and light-adapted ERG responses. Scotopic b waves were suppressed
by 24.3 ± 11.7( ±SD)%, while photopic b-waves and d-waves were suppressed
by 28.6 ±9.5% and 22 ±10.2%, respectively. Co-application of 20 umol/L
strychnine blocked the effects of glycine, suggesting that strychnine-sensitive
glycine receptors were involved. (2) 4 mmol/L glycine suppressed the light
responses of ON-type, OFF-type, and color-opponent bipolar cells, which
could be reversed by 20 umol/L strychnine. And glycine had no apparent
effect on the PIII of ERG. This result suggested that glycine exerted its
action on bipolar cells directly. (3) 4 mmol/L glycine modulated the activities
of L-type/C-type horizontal cells and rod horizontal cells. That is, glycine
hyperpolarized these cells slightly and reduced their light responses.
It was found, however, that the effect could not be blocked by strychnine
or picrotoxin, suggesting that strychnine-insensitive receptors, but not
strychnine-sensitive receptors or GABA receptors may be involved. (4) 4
mmol/L glycine hyperpolarized ON-OFF type amacrine cells, decreased their
membrane noise, while slightly enhancing their transient ON-OFF responses.
Glycine also suppressed ON-type amacrine cells.
Taken together, our results suggest that glycine may play an important
role in modulating signal pathways in the retina, such as ON-OFF pathway
, rod-cone pathway and color pathway.
-
The Paper Abstract
Glycine modulates the ON pathway in carp retina
(XU Xiang-Min, YANG Xiong-Li*)
In the present work we investigated the effects of glycine on the
electroretinograms (ERG) and light responses of ON-type bipolar cells under
dark- and light- adapted conditions in superfused, isolated crucian carp
retinas. It was revealed that application of 4 mmol/L glycine significantly
suppressed the b-waves and the responses of ON-type bipolar cells and the
effects were blocked by co-application of 20 umol/L strychnine. In addition,
glycine had no apparent action on the PIII component (photoreceptor potential)
isolated by application of 3 mmol/L glutamate. These results suggest that
glycine may modulate the activity of the ON pathway in the retina, by acting
on bipolar cells directly.
Key Words: glycine; ERG b-wave; ON-type bipolar cell; modulation;
glycine receptor
Go to Top
MY
FAVORITE WEBSITES & BBS SITES