Jupiter, Fla. June 13, 2012
Hanno-Sebastian Meyer, Senior Research Associate and Postdoctoral fellow with Bert Sakmann at MPFI’s Digital Neuroanatomy Research Group, will receive the Otto Hahn Medal of the Max Planck Society in recognition of his outstanding doctoral thesis. The work for his thesis was performed at the Max Planck Institute for Medical Research in Heidelberg. He investigated the anatomical basis of thalamic activation of neuronal networks in columns of rat vibrissal cortex. The medal, along with a cash prize of 7500 Euros, will be conferred at the Annual General Assembly of the Max Planck Society in Düsseldorf on June 13, 2012.
Since 1978, the Max Planck Society has honored several young scientists each year with the Otto Hahn Medal. It is intended to motivate especially gifted junior scientists and researchers to pursue a future university or research career.
From 2005 to 2009, Hanno-Sebastian Meyer carried out his thesis research project in the Department of Cell Physiology at the Max Planck Institute for Medical Research in Heidelberg, Germany, under the supervision of Bert Sakmann. He joined MPFI’s Digital Neuroanatomy Research Group as a postdoctoral fellow in 2009, being one of the first scientists establishing a lab at the newly founded Max Planck Florida Institute.
In his thesis research project, Hanno-Sebastian Meyer studied the anatomical basis of thalamic activation of neuronal networks in columns of rat vibrissal cortex. The dissertation comprises two main results that are crucial to the understanding of cortical processing of sensory stimuli:
In the first part of the study, for the first time, the complete cytoarchitecture of a cortical column has been measured directly, illustrated, and analyzed. The labeling of neuronal cell bodies has been performed with advanced immunohistochemical methods, the image acquisition and data analysis with newly developed methodology. This resulted in the precise measurement of the number and 3D distribution of neurons contained in a cortical column. With this data, the previously unexplained discrepancy by a factor of almost 2 of widespread estimates in the literature could be resolved. The data on the prevalence and distribution of different types of excitatory neurons in a cortical column are the fundamental basis for a quantitative description of cortical neuronal network function.
In the second part of the work, the results from the first part were used to obtain quantitative anatomical bounds for the thalamic activation of neurons in columns of primary sensory cortex. The results clearly show that all types of excitatory cortical neurons in a column (i.e. in all layers of the cortex) potentially receive substantial synaptic thalamic input. This is an essential and highly important result, as it disproves a widely-used concept about the spread of excitation in cortex. The previous paradigm of a serial activation from the thalamus to layers 4 and 6, and then to supra-and infragranular layers, is no longer compatible with the data presented here. At the same time the data reported in the study provide an anatomical explanation for the near-simultaneous activation of excitatory neurons in a cortical column as observed in physiological measurements.