The range of topics addressed in the 2000-01 M.R. Bauer
Colloquium Series was impressive. Dr.
Paul Worley, from the Department of Neuroscience
and Neurology at the Johns Hopkins University School
of Medicine, discussed his work on molecular mechanisms
activated by nerve call response to specific environments.
Using a new assay method that can identify sub-groups
of neurons within the same region of the brain, he provides
a novel glimpse into how the external environment is
represented by a network of brain cells. Dr.
Simon Giszter of Hahnemann University's Department
of Neurobiology and Anatomy explored the concept of
force-field primitives as a new framework for understanding
the psychophysical basis of human movement. Force fields
generated by biological systems may be seen as the "building
blocks" of movement, a way the organism chooses from
among the multitude of possible options in executing
motion. Dr. Kathleen
Dunlap, from the Department of Physiology at Tufts
University School of Medicine, talked about the important
role of a class of proteins in inhibiting calcium ion
channels and thereby activating the release of transmitter
chemicals essential to certain neural processes. She
showed that G-proteins bind directly to calcium channels,
a process that induces a transient inhibition of channel
activity in neurons. Dr.
Ueli Schibler from the University of Geneva's Department
of Molecular Biology explained how peripheral organs
appear to have their own biological clocks that are
reset daily by exposure to daylight. The liver's molecular
clock, for example, drives the production of enzymes
at particular times in anticipation of food consumption.
Dr. Schibler noted that much of the work explaining
the mechanisms that produce the molecular oscillations
generating circadian rhythms has been done at Brandeis.
Dr. Anthony Wagner
from MIT's Department of Brain and Cognitive Sciences
delivered a talk about why we remember certain experiences
and not others. Looking specifically at the recall of
verbal experiences, he identified processes in the left
prefrontal cortex that play a critical role in memory
regardless of variables such as attention. Dr.
Dan Johnston from the Baylor College of Medicine's
Division of Neuroscience described how scientists are
beginning to recognize the ways that dendrites, the
long branches of neurons that receive impulses, determine
the mechanisms of synaptic plasticity by which the brain
learns and adapts to experiences. He emphasized how
completely the brain cell can control its own synaptic
strength and therefore help to remember past events
and incorporate new ones as experiences warrant. Dr.
Ranulfo Romo from the University of Mexico's Department
of Neuroscience described efforts to understand the
cellular basis of perception and cognition. His goal
is to unravel the patterns of neuronal firing in the
cortex that may reveal how monkeys make simple decisions.
Taken together, the talks in the M.R. Bauer Colloquium
Series served to highlight some of the emerging developments
of neuroscience.
Now in its third year, the M.R. Bauer Distinguished
Guest Lecturer Series brought to campus two of the most
eminent scientists in the field. Professor
Roger Nicoll, a member of the National Academy of
Sciences, is the Morris Herzstein Professor at the University
of California, San Francisco, and a member of UCSF's
W.M. Keck Foundation Institute for Integrative Neuroscience.
He is well known for having shown how drugs and transmitter
chemicals work in the nervous system, for revealing
the subtlety and complexity of signaling in the brain,
and for providing new insights into the plasticity of
the central nervous system. Nicoll's visit coincided
with the Volen Center's annual M.R.
Bauer Foundation Scientific Retreat at Woods Hole,
Massachusetts, at which he presented the keynote lecture.
Nicoll's talk, on "Presynaptic Plasticity and the Redistribution
of Glutamate Receptors," showed how important certain
receptors are to the processes of learning and memory.
In a separate talk, he also shed light on the role that
drugs such as marijuana play in changes in cognitive
function.
This year's second M.R. Bauer Distinguished Guest Lecturer
was William T. Newsome
III, professor of neurobiology at the Stanford University
School of Medicine. An Investigator of the Howard Hughes
Medical Institute and a member of the National Academy
of Sciences, Newsome has provided a deeper understanding
of the way in which neural mechanisms mediate basic
cognitive functions such as motion perception. He is
widely renowned for work that relates cellular function
in the primate brain to behavior. His public lecture,
"From Neurons to Perception," presented convincing evidence,
based on his long-term research on the visual system,
that linked the firing of individual neurons to behavioral
judgments with respect to directional movement. He also
demonstrated that vision is created when the brain chooses
the neuron that is working most effectively, rather
than averaging all the signals of visual neurons. Newsome's
findings may prove important for the development of
treatments for blindness and neurological disorders.
The 2001 Volen Center Retreat sponsored by the M.R.
Bauer Foundation focused on "consciousness." Held at
the Marine Biological Laboratory at Woods Hole on February
20 and 21, the retreat featured a lecture by the Bauer
Distinguished Guest Lecturer Professor Roger Nicoll
(described above), as well as a special presentation
by Dr. Hod Lipson
of Brandeis's computer science department. Lipson, who
works with Professor Jordan B. Pollack of Brandeis's
computer science department, talked about their breakthrough
in creating robots that can autonomously design and
fabricate new robots, which received front-page coverage
in The New York Times in August 2000. In his talk at
the retreat, "Automatic Design and Manufacture of Robotic
Lifeforms," he elaborated the experiments through which
they created systems that can sustain their own evolution.
Their work represents the first time that an artificial
evolution system has been connected to an automatic
physical construction system. They created an evolutionary
computational process by which fitter machines were
selected from a population of 200 candidate robots.
While many further steps would be needed before this
technology might become dangerous, it is clear that
these robots cross the simulation-reality gap and affect
the physical world directly. Future work will be focused
on understanding how more complex structures might self-
organize and how these machines may be made under the
control of the evolutionary process.
A panel discussion, involving Professor of Biology
John Lisman, Associate
Professor of Philosophy Jerry Samet, and neuroscience
graduate student Chaelon Myme, addressed a central question
of consciousness: How does the brain represent the world
in our minds? Samet provided an overview of the history
of the study of consciousness by philosophers from Descartes
to the present. Lisman spoke about the underlying mechanisms
of consciousness, particularly a neural receptor that
is essential to working memory, perhaps the most important
element in consciousness. He is optimistic about the
possibility of applying rigorous scientific approaches
to the study of consciousness. Myme described the "neural
correlates of consciousness," and suggested that the
circuitry of the inferotemporal (IT) cortex in the brain
may be found to provide the neural mechanisms of consciousness.
While some participants at the retreat thought it might
be premature to describe consciousness in mechanistic
terms, links between widely separated disciplines are
beginning to be established. The 2001 M.R. Bauer Scientific
Retreat helped faculty and students to think about the
larger issues that frame their research, and underscored
why the Volen Center's interdisciplinary approach has
proven to be so successful.
Having completed seven years, the M.R. Bauer Foundation
Colloquium and Scientific Retreat have been highly effective
in promoting the exchange of ideas and methods across
disciplinary boundaries, in advancing the study of neuroscience,
and in fostering a sense of community among the neuroscientists
at Brandeis and elsewhere. The M.R. Bauer Distinguished
Guest Lecturer Series has added a new dimension to these
activities over the past three years. These published
proceedings represent a major element in the Volen Center's
effort to encourage scientific collaboration and discussion.
I am especially pleased to thank the M.R. Bauer Foundation
for supporting these important activities.
Leslie Griffith,
M.D., Ph.D.
Associate Professor of Biology and Acting Director
Volen National Center for Complex Systems
