The Summer Workshop 2011
Theme: Development of Brain and Mind
Date: |
August21-22,2011 |
Place: |
Kobe International Conference Center, Kobe, Japan |
Schedule:
August21(Sun) |
Special Session1
|
|---|---|
| 14:40-15:30 | Importance of early experience for development of visual processing Yoichi Sugita (Advanced Industrial Sci and Tech) |
| 15:30-16:20 | Constructive Cortical Computation Rodney Douglas (University of Zurich / ETH Zurich) |
| 16:20-16:40 | Break |
| 16:40-17:30 | Early development of functional network of the cortex in infants Gentaro Taga (Tokyo University) |
| 17:30-18:20 |
Humanoid Roboticss and Neuroscience:
Two Sides of the Same Coin |
| 18:20-18:50 | Discussion |
| Poster Session 18：50-21：00 | |
|
August22(Mon) |
Special Session 2 |
| 09:00-09:50 |
Maternal-fetal interactions and
5-HT modulation of fetal brain wiring Alex Bonnin (University of Southern California) |
| 09:50-10:40 | The Teen
Brain Jay N. Giedd (Child Psychiatry Branch, NIMH) Slides presented at the symposium:pdf（4.16Mbyte） |
Abstracts and References：
Yoichi Sugita
National Institute of Advanced Industrial Science and Technology
Importance of early experience for development of visual processing
Early visual experience is indispensable to shape the maturation of cortical
circuits during development. Monocular deprivation in infancy, for instance,
leads to an irreversible reduction of visually driven activity in the visual
cortex through the deprived eye and a loss of binocular depth perception.
It was tested whether or not early experience is also necessary for color-,
motion-, and complex form such as face perception. Infant monkeys were
reared for nearly a year in a separate room where the illumination came
from only monochromatic lights. After extensive training, they were able
to perform color matching. But, their judgment of color similarity was
quite different from that of normal animals. Furthermore, they had severe
deficits in color constancy; their color vision was very much wavelength-dominated,
so they could not compensate for the changes in wavelength composition.
Another infant monkeys were reared for nearly a year in a room where the
illumination came from 10 Hz stroboscopic lights so that they could not
perceive visual motion. They were able to perform an orientation matching
task. However, their performance was quite poor for speed or direction
matching. Furthermore, they had severe deficits in perceiving global motion.
These results indicate that early visual experience is also indispensable
for color- and motion perception. Finally, another infant monkeys were
reared with no exposure to any faces for 6 to 24 months. Before being allowed
to see a face, the monkeys showed preference for photographs of human-
and monkey faces, and discriminated human faces as well as monkey faces.
After the deprivation period, the monkeys were exposed first to either
human or monkey faces for a month. Soon after the monkeys selectively discriminated
the exposed species of face, and showed a marked difficulty in regaining
the ability to discriminate the other non-exposed species of face. These
results indicate the existence of an experience-independent ability for
face-processing as well as clear sensitive period during which a broad
but flexible face prototype develops into a concrete one for efficient
processing of familiar faces.
Reference
1)Yoichi Sugita Innate face processing. Current Opinion in Neurobiology 19, 39-44 (2009)
2)Yoichi Sugita Face perception in monkeys reared with no exposure to faces. Proceedings of National Academy of Science, USA. 105, 394-398 (2008)
3)Yoichi Sugita Experience in early infancy is indispensable for color perception. Current Biology 14, 1267-1271 (2004)
Rodney Douglas and FET SECO IP
University of Zurich/ ETH Zurich
Constructive Cortical Computation
During the past century ever more sophisticated methods have been developed for constructing and programming computing and manufacturing machines. However, these methods are essentially forward processes that depend on intelligent human designers and programmers. Biological systems use an entirely different concept of construction than that of human artifacts. They construct themselves by a process that is a systematic spatio-temporal genera-tion of, and interaction between, various specialized cell types. Understanding this radically different approach that uses algorithmic self-programming and -construction could have enormous consequences for future computing and manufacturing technologies. We (http://www.seco-project.eu/) are exploring these principles of self-construction in the context of the development of the neocortex, where the construction of elaborate information processing circuits depends strongly on a relatively small amount of information encoded in the genome of neuronal stem cells. Our approach combines experimental observation of cortical development together with detailed simulation of the physical process itself. Because self-construction implies interactions between low level elements in a physical world, our first step has been to design a simulation framework for realistic representation of neurons in 3D space. To this end we have developed a JAVA-based framework, CX3D, for simulating neural development [1]. This software can be downloaded from http://www.ini.uzh.ch/projects/cx3d/. CX3D provides a physical space governed by a physics engine that computes the forces between objects, and the diffusion of substances through the space. The neurons of CX3D are composed of discrete physical components such as spheres (somata) and chains of cylinders (neurites), each located at a particular point in 3D space. All these components interact locally with one another, simulating the physical and biological processes occurring in the tissue.
By analogy with biology, the developmental process within each cell of CX3D is dependent on an XML genome-like code that encodes implicitly the various instructions of the cell lineages that will lead to the formation of the overall neocortex. We have demonstrated how such a code can be constructed, and then incorporated into a single cortical
stem cell that then expands by mitosis, differentiation, and morphological specialization into the multilayer connected neural network of neocortex. Thus far, the final cortical structures are composed of about 0.25M cells, appropriately laminated, and with patterns of intra- and inter-laminar connectivity that are similar to those observed experimentally [2]. The outgrowing axons are able to form synapses dynamically with the dendrites of target neurons, which may express a suitable selective label. On-going research is exploring the interaction between the morphological growth, synapse allocation, and electrophysiology of neurons during cortical development.
Reference
[1] F. Zubler, R. Douglas, A framework for modeling the growth and development of neurons and networks, Frontiers in Computational Neuroscience 3:1-16, (2009)
[2] T. Binzegger, R. J. Douglas, K. A. C. Martin, A quantitative map of the circuit of cat primary visual cortex., J Neurosci 24:8441–8453,(2004)
Gentaro Taga
Graduate School of Education, University of Tokyo
Early development of functional network of the cortex in infants
Multi-channel near infrared spectroscopy (NIRS) has been used to investigate spatio-temporal dynamics of activation of the cortex in young infants. Studies on stimulus-induced cortical activation in relation to perceptual-cognitive ability have demonstrated the early functioning not only in sensory regions but also in the association and higher association regions as early as 3 months of age. Studies on spontaneous activity during sleeping state as well as the stimulus-induced activity has further revealed developmental changes in the global cortical network of the functional connectivity. These studies suggest that the functional hierarchy of the cortical regions may concurrently emerge from the dynamic interaction of diverse regions of the cortex in early infancy.
Reference
H. Watanabe, F. Homae, G. Taga: General to specific development of functional activation in the cortexes of 2- to 3-month-old infants. NeuroImage 50, 1536-1544, 2010
F. Homae, H. Watanabe, T. Otobe, T. Nakano, T. Go, Y. Konishi, G. Taga: Development of global cortical networks in early infancy. Journal of Neuroscience 30: 4877-4882, 2010
F. Homae, H. Watanabe, T. Nakano, G. Taga: Large-scale networks underlying language acquisition in early infancy. Frontiers in Psychology 2, 93, 2011
G. Taga, H. Watanabe, F. Homae: Spatiotemporal properties of cortical hemodynamic response to auditory stimuli in sleeping infants revealed by multi-channel NIRS. Phil. Trans. R. Soc. A. (in press)
Giulio Sandini
Robotics, Brain and Cognitive Sciences Department, Italian Institute of Technology
Humanoid Roboticss and Neuroscience: Two Sides of the Same Coin
The aim of this talk is to demonstrate that, to study how humans execute and understand actions, robotics and neuroscience research can be mutually supportive by providing their own individual complementary investigation tools and methods: neuroscience from an “analytic” perspective and robotics from a “synthetic” one. In order to demonstrate this synergy between neuroscience and robotics I will start by briefly reviewing the history of neuroscience and robotics in the last 30 years to show that the two fields have indeed progressed in parallel even if, until now, on almost independent tracks. I will then show that, due to recent discoveries by neuroscientists, the implementation of perceptive and complex humanoid robots has become not only a very powerful modeling tool of human behavior (and the underlying brain mechanisms) but also an important source of hypothesis regarding the mechanisms used by the nervous system to control our own actions and to predict the goals of someone else’s actions. During the talk I will present results of recent psychophysical investigations in children and human adults as well as artificial implementations in our baby humanoid robot iCub.
Alexandre Bonnin
Dept. Cell & Neurobiology
Keck School of Medicine of University of Southern California
Maternal-fetal interactions and 5-HT modulation of fetal brain wiring
Serotonin(5-HT) is thought to regulate neurodevelopmental processes through
maternal–fetal interactions that have long-term mental health implications.
For example, we recently showed that 5-HT modulates the response of thalamocortical
axons to classic guidance cues, and therefore influences fetal brain wiring
in vivo. It is thought that beyond fetal 5-HT neurons there are significant
maternal contributions to fetal 5-HT during pregnancy but this has not
been tested empirically. We examined putative central and peripheral sources
of embryonic brain 5-HT, and detected previously unknown differences in
accumulation of 5-HT between the forebrain and hindbrain during early and
late fetal stages, through an exogenous source of 5-HT which is not of
maternal origin. Using additional genetic strategies, a new technology
for studying placental biology ex vivo and direct manipulation of placental
neosynthesis, we investigated the nature of this exogenous source. We uncovered
a placental 5-HT synthetic pathway from a maternal tryptophan precursor
in both mice and humans. This study reveals a new, direct role for placental
metabolic pathways in modulating fetal brain development and indicates
that maternal–placental–fetal interactions could underlie the pronounced
impact of 5-HT on fetal programing of adult diseases.
Reference
Alexandre Bonnin, Masaaki Torii, Lilly Wang, Pasko Rakic & Pat Levitt:
Serotonin modulates the response of embryonic thalamocortical axons to
netrin-1 pdf
Alexandre Bonnin, Nick Goeden, Kevin Chen, Melissa L.Wilson, Jennifer King,
Jean C. Shih, Randy D. Blakely, Evan S. Deneris & Pat Levitt: A transient
placental source of serotonin for the fetal forebrain pdf
Jay N. Giedd
Child Psychiatry Branch,NIMH
Slides presented at the symposium:pdf（4.16Mbyte）
Since 1991 my team at the Child Psychiatry Branch of the National Institute of Mental Health has used brain imaging, genetics, and psychological assessments to explore the neurobiology of cognitive/emotional/behavioral development in health and illness. The study design is for subjects from ages 3 to 30 years to be evaluated longitudinally at approximately 2-year intervals. As of July 2011 the data set comprises over 8000 scans from over 3000 subjects – ¼ from typically developing singletons, ¼ from typically developing MZ or DZ twins, and ½ from 20+ clinical populations including ADHD, Autism, and Childhood Onset Schizophrenia. Structural MRI data demonstrates roughly linear increases in white matter during the first three decades of life. Cortical and subcortical gray matter volumes generally follow an inverted U shaped developmental trajectory with peak size occurring at different ages in different regions. Particularly late to stabilize to adult cortical thickness is the dorsolateral prefrontal cortex, an area involved in neural circuitry subserving impulse control, decision making, and long term planning. Functional MRI studies indicate a greater integration of brain components and a diffuse to focal activation pattern with increasing age. During adolescence there is a changing balance between earlier puberty related maturation of limbic structures and later maturing frontal regions. Twin studies show that heritability of brain morphometry varies substantially by age and region. Male brain measures are more variable and females, as a group, have earlier peak sizes of gray matter. The relative contributions of the X and Y chromosomes vs hormones is evaluated by studies of people with sex chromosome variations (i.e. XO, XXX, XXY, XYY, XXYY, XXXXX, and XXXXY) and of people with anomalous hormone profiles (i.e. Congenital Adrenal Hyperplasia, Cushing Syndrome, Familial Male Precocious Puberty, and Androgen Insensitivity Syndrome). The effects of specific genes and the impact of psychopathology on brain developmental trajectories will also be discussed.Reference
Jay N. Giedd and Judith L. Rapoport, Structural MRI of Pediatric Brain Development: What Have We Learned and Where Are We Going?,Neuron, 2010 pdf
Jay N. Giedd,The Teen Brain: Insights from Neuroimaging,Journal of Adolescent Health,2008 pdf