Menno Witter was born in The Netherlands in 1953. He did his PhD with professors Anthony Lohman and Fernando Lopes da Silva at the VU University and VU medical center in Amsterdam, where he published the first detailed anatomical account of the organization of the entorhinal cortex, focusing on its role in hippocampal-cortical interactions (1985). After his Ph.D., he worked with David Amaral and Gary VanHoesen in the US (1985/1986) on the organization of the entorhinal-hippocampal system in primates and continued to work as assistant professor in the department of Anatomy at the Vrije University. In 1989 he published two influential papers on the anatomy of the cortico-hippocampal system, which still are considered 'classics' in the field. In these papers he proposed functional differentiation within the hippocampus and parahippocampus, an issue which is now at the heart of some of the more promising research lines in the hippocampal field. In 1990, together with David Amaral, he initiated the launch of the journal Hippocampus, which, now being in its 19th year, is a major vehicle for communication among scientists in the field. As of 1990, he headed his own research group, focusing on the functional organization of the medial temporal lobe (MTL), in particular in relation to learning and memory and Alzheimer's disease. In 1993, he worked as a visiting scientist and senior consultant with Prof. Dr. G. Matsumoto and Dr. T. Iijima, ETL, Tsukuba, Japan, where he started to use voltage-sensitive dye imaging to study network properties of the hippocampal-parahippocampal system. This powerful approach resulted in the description of networks potentially mediating reverberation, a proposed mechanism for memory storage. This collaboration has continued over the years, focusing on possible interactions between multiple input pathways onto identified neuronal populations.

In 1995, he was appointed as full professor in Anatomy and Embryology at the VU University Medical Center where he continued his work on functional anatomy of the cortico-hippocampal system, combined with in vivo electrophysiology and human functional MRI studies. He contributed significantly to our understanding of parallel input-output pathways between the parahippocampal region and the hippocampus, and the possibility of functional heterogeneity between hippocampal and parahippocampal subfields as well as within the individual subfields. In addition, on the basis of clinical and experimental data, he published a series of influential papers on the role of the midline and intralaminar thalamus in cognition and its contribution to diencephalic amnesia and frontal syndromes. In 1999 he was appointed as scientific director of the Institute for Neuroscience of the VU/VUmc and as director of the Graduate School Neuroscience Amsterdam. He was one of the founding directors of the Center for Neurogenomics and Cognitive Research VU/Vumc (2003).

In 2004 he was appointed as visiting professor in the Centre for the Biology of Memory and the Kavli Institute for Systems Neuroscience at the Norwegian University for Science and Technology (NTNU) in Trondheim. In 2007 he moved to Trondheim, where he continues his work on functional anatomy of the cortico-hippocampal system, relevant to memory processes in particular to spatial memory and navigation. He combines anatomical approaches with in vitro electrophysiology. His current research interests include the study of functional differentiation between cell types and cell layers in the entorhinal cortex, structural and connectional differences between the lateral and medial entorhinal cortex and the development of the entorhinal cortex and its connections. He is also involved in human functional MRI studies that focus on understanding functional heterogeneity within the human MTL.

 

Affiliations

Contact details

Menno Witter, PhD
Professor Neuroscience, Dept. Neuroscience
Kavli Institute for Systems Neuroscience, Centre for the Biology of Memory
MTFS, Norwegian University of Science and Technology (NTNU)
NO-7489 Trondheim, Norway
Phone: +47 73598249
Fax: +47 73598294
Email: menno.witter at(@) ntnu.no

pubmed: witter mp[author]

NCBI: db=pubmed; Term=Witter MP[Author] NCBI pubmed
  • Related Articles Excitatory Postrhinal Projections to Principal Cells in the Medial Entorhinal Cortex. J Neurosci. 2015 Dec 2;35(48):15860-74 Authors: Koganezawa N, Gisetstad R, Husby E, Doan TP, Witter MP Abstract UNLABELLED: The postrhinal cortex (POR) provides substantial input to the entorhinal cortex, mainly targeting superficial layers of the medial entorhinal cortex (MEC). Major inputs to POR originate in the visual and parietal cortex, thus providing neurons in MEC with a subset of cortical information relevant to their spatial firing properties. The POR takes a position that is comparable with that of the perirhinal cortex (PER) with regard to the lateral entorhinal cortex (LEC). Neurons in LEC and MEC show different functional properties likely reflecting differences in their respective inputs. Projections from PER to LEC exert a main inhibitory influence, which may relate to the sparse object-selective firing in LEC. In view of the continuous, spatially modulated firing properties of principal neurons in MEC, we tested in rats the hypothesis that projections from POR to MEC are functionally different from the PER-to-LEC counterpart in providing an excitatory drive to MEC. Our combined confocal and quantitative electron-microscopic observations indicated that POR projections target mainly principal cells in MEC, including neurons that project to the hippocampus. The ultrastructure of the majority of the synapses indicated that they are excitatory. Voltage-sensitive dye imaging in sagittal slices confirmed this morphologically derived conclusion, showing that the MEC network always responded with an overall depolarization, indicative for net excitatory transmission. In vitro single-cell recordings from principal cells showed only excitatory responses upon POR stimulation. These results show that POR provides an excitatory projection to MEC, differing fundamentally from the inhibitory projection of PER to LEC. SIGNIFICANCE STATEMENT: The study provides anatomical and electrophysiological data indicating that projections from the postrhinal cortex to the medial entorhinal cortex (MEC) are excitatory, providing the substrate for high probability of information transfer and thus a continuous input stream into MEC. This is a relevant component of the spatial navigational network found in MEC. The findings are in contrast to previous reports on the parallel pathway from the perirhinal cortex to the lateral entorhinal cortex. This pathway, characterized by a preponderance of inhibitory connections, mediates information transfer with a low probability, likely related to the discontinuous object-related firing of neurons in the lateral entorhinal cortex. PMID: 26631468 [PubMed - in process]

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