On 21 April 2002, the Cajal Club presented the Cortical Discoverer Awards to Drs Thomas A. Woolsey and David Van Essen, the Cortical Explorer Awards to Drs László Acsády and Gábor Tamás, and the Cortical Scholar Award to Dr Michelle M. Adams. The site of this year’s Cajal Club meeting was New Orleans, Louisiana. The Krieg Cortical Kudos Awards Committee consisted of Charles E. Ribak (President), Peter Ralston (Secretary/Treasurer), Tamás Freund, Enrico Mugnaini, Pasko Rakic and Leslie Ungerleider.

The Cortical Discoverer Awards

The highest level award, the Cortical Discoverer prize ($5000), is given to a senior scientist who has contributed significantly to our understanding of the cerebral cortex. There were two awards in this category this year, and they were presented to Drs Thomas A. Woolsey and David Van Essen. Both of these scientists have demonstrated a lifetime of achievements in the understanding of cortical structure and function.

Thomas A. Woolsey was recognized for his pioneering work of mapping the mouse sensory fields in the cerebral cortex. He discovered that the tactile map was dominated by the whiskers and further showed that each whisker is represented by a ring-like structure in layer IV, that he and Dr Hendrik Van der Loos called a barrel. Dr Woolsey has spent his career analyzing the structure and function of barrels using cellular morphology, physiology, connectivity, development, histochemistry, plasticity, modeling and vascularization. His lecture was entitled, ‘Whiskers and Barrels’.

Tom’s beginning in neuroscience started much earlier than probably any other scientist in this field. Most scientists talk about lineage or pedigree in terms of whom we trained with. It is important to point out that Tom’s lineage was biological: his father was Clinton Woolsey, the pioneer of mapping the sensory cortical fields electrophsyiologically in a wide variety of mammals. As a result of his father’s advice, Tom chose a thesis project at Johns Hopkins Medical School to map the mouse sensory fields. Indeed, the mouse somatosensory cortex had not been mapped with electrophysiological methods prior to Dr Woolsey’s work. As mentioned above, this region of cortex is dominated by the whiskers, overwhelming the rest of the body in its spatial expanse. Using detailed neuroanatomical methods (Woolsey and Van der Loos, 1970), Tom and Hendrik showed that rings of neuronal somata were present in tangential sections of layer IV. After reconstructing the rings from several sections, they saw a pattern that resembled the rows of whiskers on the snout. Of course, they recognized that the rings of neurons looked like the barrels in a Breughel engraving, and thus gave them the name that has catalyzed many cortical discoveries. The correspondence of whiskers and barrels has become a symbol for the modern understanding of the relationship between structure and function in the cerebral cortex.

Tom’s training after Johns Hopkins University continued with a postdoctoral fellowship at the Department of Anatomy at Washington University in St Louis, Missouri in 1970. Only a year later, he was appointed an Assistant Professor and he rapidly climbed the academic ladder to become Full Professor in 1983. A year later, he was appointed the Director of the James L. O’Leary Division of Experimental Neurology and Neurological Surgery and the George H. and Ethel R. Bishop Scholar in Residence in Neuroscience at Washington University.

In papers subsequent to this initial discovery of barrels, Tom showed that lesions of several whiskers in a row or across rows caused the corresponding ‘barrels’ in the cortex to be affected; these barrels did not develop. Also as a result, the remaining barrels grew larger. Dr Woolsey also described in Golgi preparations how the neurons in the wall of the barrel sent their dendrites into the hollow of each barrel where a plume of thalamocortical axons terminated. Other studies have employed metabolic markers to show how repetitive stimulation of a single whisker correlated with high activity in its corresponding barrel. His most recent work focused on the vascular pattern in barrels and how activity affects the size of the capillary bed. In addition to these excellent studies, Tom has published findings on other aspects of barrels. These studies appear in over 90 papers in outstanding journals and in many book chapters.

Another measure of Dr Woolsey’s influence on the field of somatosensory research is the fact that a professional society — the Barrels Club — has come into being whose focus is on his work and on subsequent findings. This organization owes its existence to the work of Tom Woolsey, much as the Cajal Club owes its to Santiago Ramón y Cajal. It should be noted that the annual meetings of the Barrels Club are held in association with the Society for Neuroscience meetings. They recently convened their 14th annual meeting, making it the longest running satellite meeting of the Society for Neuroscience. Both Tom and Hendrick birthed the first such meeting, and its tremendous success over the years, as evidenced by annual attendance exceeding 100 participants, is due to Tom’s continuing commitment, engagement and leadership. It also needs to be noted that two other Krieg Cortical Kudos Discoverers have won prizes for their work on barrels, Drs Herbert Killackey and Edward White.

The Krieg Cortical Kudos is not the first award that Tom has received for his exciting research discoveries. In 1982, he was given a McKnight Neuroscience Development Award. In 1993, he was bestowed with a Javits Neuroscience Investigator Award. Other notable activities include being Editor-in-Chief of the journal Somatosensory and Motor Research since 1995, and being a Fellow of the American Association for the Advancement of Science since 2000. In addition, he served as the President of the Cajal Club in 1995–1996 and was honored by the Cajal Club for his outstanding research when he was selected its Pinckney J. Harman Lecturer in 1987. Tom has been available for consultation during my tenure as President of the Cajal Club and I personally thank him for the time he spent teaching me the nuances of how the Club operates. From all of the preceding, it is only fitting and proper for the Cajal Club to present the Cortical Discoverer Award to Dr Thomas Woolsey in 2002.

David Van Essen was honored for his contributions to our understanding of the visual areas of the primate cerebral cortex. He not only mapped multiple visual areas within the parietal and temporal lobes of the cerebral cortex but also formulated a hierarchial model of cortical connectivity through his analysis of the interconnections of these various visual areas. He elucidated the functional specializations of numerous visual areas and proposed a tension-based mechanism for morphogenesis of the central nervous system. David is currently the Edison Professor of Neurobiology and Department Head of Anatomy and Neurobiology at Washington University School of Medicine. The title of his talk was, ‘Mapping Structure and Function in Cerebral Cortex: A Cortical Cartographer’s View of the Past, Present and Future’.

David started his secondary education at the California Institute of Technology (Cal Tech) in Pasadena, California where he earned his bachelor of science degree in chemistry in 1967. He then went to Harvard Medical School and obtained his Ph.D. in 1971 in neurobiology under Dr John Nicolls, an expert in electrophysiology of the leech. He then remained at Harvard for a two-year postdoctoral fellowship with Nobel Laureates Drs David Hubel and Torsten Wiesel before traveling to Oslo, Norway where he worked with Dr J. Jansen. While at Harvard Medical School, David collaborated on some pioneering work with James Kelly in which they correlated the morphology of simple and complex neurons in the cat visual cortex with stellate and pyramidal cell morphology. After a brief one-year fellowship with Dr S.M. Zeki, David became an Assistant Professor at Cal Tech in 1976.

This Cal Tech phase of David’s career allowed him to pursue his interests in the visual system. His interests began in earnest with his discovery of the middle temporal visual area (MT) in the macaque in 1981. He used sophisticated tract tracing methods and electrophysiology to map the connections of the MT with primary visual areas and to determine the functional properties of neurons in this region, respectively. He also went back to the primary visual cortex and did a further mapping of ocular dominance columns during this period, following in the footsteps of Drs Hubel and Wiesel. David’s next foray was the secondary and tertiary visual cortices, affectionately referred to as V2 and V3, respectively. Later in 1986, he discovered that regions of the parietal cortex also had visual representation. These studies capped his notion of the existence of multiple visual cortical areas outside the occipital lobe and led to an important paper in 1990 on the ‘Modular and hierarchial organization of extrastriate visual cortex in the macaque monkey’ (Van Essen et al., 1990).

Shortly after this publication, Dr Van Essen was recruited to Washington University to become the Department Head of Anatomy and Neurobiology in 1992. At this institution, David continued his studies of the extrastriate visual areas by performing additional research on what appears to be his favorite cortical area, MT. In addition, he used computational methods for reconstructing and unfolding the cerebral cortex. One of the difficulties involved in this mapping is the fact that these visual areas are usually buried in complex and irregular sulci. Both the depth and irregularity of cortical convolutions have been a chronic impediment to visualizing spatial relationships among the complex mosaic of visual areas. David showed how surface-based atlases could be used to analyze cortical organization. By first blowing up the brain and all of its sulci into a globe and then using cartographic tools, he demonstrated a flat map of the primate cerebral cortex. More recently, he has explored functional specializations of the human cerebral cortex through functional and structural mapping of its surfaces. This work on the extrastriate visual cortex shows that the human has an expanded area as compared to the monkey, particularly in the parietal lobe. Finally, as one of his nominees writes, ‘his seminal hypothesis regarding mechanical tension during morphogenesis can account for many previously puzzling aspects of cortical convolutions. Altogether, Dr Van Essen has deeply influenced our current understanding of the structure, function and development of the primate cerebral cortex.’

It should be noted that David Van Essen has published over 80 research papers in outstanding journals and over 35 invited book chapters. He has served on many editorial boards including the Journal of Neuroscience, Neuroscience Research and Cerebral Cortex. His honors include being elected a Fellow of the American Association for the Advancement of Science and several teaching awards at Washington University. He has served on several boards, including the Howard Hughes Medical Institute and the Society for Neuroscience. The Cajal Club was pleased to present one of two Cortical Discoverer Awards for 2002 to Dr David Van Essen.

The Cortical Explorer Awards:

The Cortical Explorer prize ($3000) is usually awarded to a scientist at an intermediate stage of their career for achievements within six years of receiving an advanced professional degree (Ph.D./MD). This year, two awards were also made in this category, one to Dr László Acsády and one to Dr Gábor Tamás. Both of them have made many contributions to our understanding of cortical structure and function.

László Acsády was recognized for his contributions to the neuroanatomical connections of interneurons in the hippocampal formation. Using intracellular labeling with immuno-cytochemistry, he revealed an important organizational principle for the mossy fiber system. He has made other contributions about the structure and function of hippocampal neurons. His talk was entitled, ‘A Unique Gyrus – Unusual Properties of the Neocortex–Archicortex Interface’.

Dr Acsády was born and educated in Budapest, Hungary. He had summer research positions in both the 1st Department of Anatomy at Semmelweis University and the Institute of Experimental Medicine while attending the Eötvös Lóránd University for his master of science degree in biology. He earned his Ph.D. at the same university in 1996 under the direction of Dr Tamás Freund, a former Krieg Cortical Kudos Discoverer and Explorer Awardee. The title of László’s thesis was: ‘The synaptic connectivity and subcortical afferentation of hippocampal interneurons’. According to Dr Freund, the ‘backbone’ of his thesis involved untangling the connections of the VIP-containing neurons in the hippocampus. This subset of GABAergic neurons was shown to innervate other GABAergic interneurons and principal neurons of the hippocampus.

After obtaining his Ph.D. degree, László worked in the laboratory of Dr Gyorgy Buzsáki (last year’s Krieg Cortical Kudos Discoverer Awardee) at Rutger’s University for a year where he combined intracellular labeling with immunocytochemistry for an analysis of the mossy fiber system. He examined synapses made by mossy fibers in the rat hippocampus and identified the postsynaptic cell type and the complexity of the synapse. In a landmark publication in the Journal of Neuroscience (Acsády et al., 1998), he and his associates reported that the GABAergic neurons in the rat hippocampus are the major postsynaptic targets of mossy fibers. In this study, they showed that the co-called ‘mossy fibers’ formed only 11–15 synapses with CA3 pyramidal cells and 7–12 synapses with hilar mossy cells. However, the small, specialized terminal appendages of these mossy fibers formed ten times the number of synapses with GABAergic neurons. These findings suggested that granule cells innervate inhibitory GABAergic neurons more than excitatory neurons in the hippocampus. Also, they showed that granule cells form different types of terminals to innervate GABAergic neurons and pyramidal cells. These findings may explain the physiological observation that increased activity of granule cells suppresses the overall excitability of the CA3 recurrent system.

Following this postdoctoral period, Dr Acsády returned in 1997 to the Institute of Experimental Medicine in Budapest, Hungary as a Senior Research Fellow. Currently, he works on the functional neuroanatomy of the thalamocortical system. His most recent findings indicate that a novel GABAergic afferent pathway exists that specifically targets higher-order and intralaminar thalamic nuclei. It is clear that László has the potential to make many important contributions in his future.

It should also be noted that László Acsády has won several other prizes for his research. These include the Academy Prize for Young Scientist in 1996 and the Janos Bolyai Scholarship in 1998, both from the Hungarian Academy of Sciences and the 2000 Prize from the Hungarian Electron Microscopic Society. He also serves as a Deputy Editor of the European Journal of Neuroscience for the section on cytology, cellular and systems neuroscience.

Gábor Tamás, the other Cortical Explorer for 2002, was honored for his systematic and pioneering contributions to the quantitative synaptic definition of functionally characterized cortical circuits in the visual cortex of cats. In his studies, he identified chemical and electrical synapses between pairs of cortical neurons using combined physiological, morphological and immunocytochemical techniques in slices. The title of his talk was ‘Processing of Convergent Information in Identified Cortical Networks’.

Dr Tamás was born in 1969 in Dunaujvaros, Hungary, close to the Danube River. He earned his masters in science degree from the Attila József University in Szeged, Hungary under the direction of Dr Norbert Halasz. He then continued his education with Ph.D. training at two universities, Attila József University in Szeged, Hungary and Oxford University, England and under the supervision of three mentors, Drs Katalin Halasy, Peter Somogyi (a former Krieg Cortical Kudos Discoverer Awardee) and Eberhard Buhl. For his thesis that he completed in 1996, he analyzed pairs of neurons in the visual cortex of cats. In the course of this analysis, one of his thesis advisors, Dr Peter Somogyi, stated, ‘He has identified and analyzed the largest known sample of electron microscopically identified chemical and electrical synapses between pairs of cortical neurons that were functionally characterized for their effects.’ Using acute cortical slices in vitro, Gábor and his colleagues combined physiological, morphological and immunocytochemical techniques for the identification of neurons and the nature of their synaptic interactions. An example of his elegant analysis was shown in his paper in Nature Neuroscience (Tamás et al., 2000) where he identified both chemical and electrical synapses formed between two GABAergic neurons. This electron microscopic study revealed spatial proximity of gap junctions and GABAergic chemical synapses on somata and dendrites of pairs of GABAergic neurons and indicated that they could provide an important basis for the synchronization of cortical interneurons.

Gábor Tamás continued his studies at Oxford University with Drs Buhl and Somogyi as a Visiting Research Scholar in 1996–1997. Then, he returned to Hungary in 1997 as a lecturer at Attila József University before being appointed an Assistant Professor and János Bolyai Research Scholar at the University of Szeged. During this period (1996–2000), Gábor showed how networks of GABAergic neurons might synchronize activity at gamma frequencies (30–70 Hz) in the rat somatosensory cortex using electrophysiological and electron microscopic methods. His elegant studies showed that the combined electrical and GABAergic synaptic coupling of basket cells instantaneously entrained gamma-frequency postsynaptic firing in layer 2/3. Also, he showed that this entrainment was mediated by rapid curtailment of gap junctional coupling potentials by GABAA receptor-mediated IPSPs. Together, these studies demonstrated precise spatiotemporal mechanisms underlying action potential timing in oscillating interneuronal networks.

It is important to note that Dr Tamás made four other significant contributions. First, he discovered a GABAergic cell type that targets dendrites of pyramidal cells and showed conclusively that they are distinct from basket cells. Second, he discovered that dendritic spines are the major synaptic targets of double bouquet cells. Third, he showed that GABAergic neurons make large numbers of synapses with themselves, so-called autaptic junctions. And fourth, he demonstrated a network of gap junctions in the regular spiking non-pyramidal cells, another class of GABAergic neuron.

The extent and significance of these research discoveries have been noticed in that Gábor has won several prizes. They include the Young Investigator’s Award in 2001 from the 34th International Congress of Physiological Sciences, the János Bolyai Research Scholarship in 2000 from the Hungarian Academy of Sciences in Budapest, and the Ferenc Joó Prize in 1997 from the Hungarian Academy of Sciences from Szeged, Hungary. We shall look forward to Gábor’s future contributions in his career, and anticipate that his studies will continue to add to our understanding of the structure and function of the cerebral cortex.

The Cortical Scholar Award

The Cortical Scholar prize ($1000) is awarded to a predoctoral fellow who is at the endstage of completing their doctoral dissertation or within one year of obtaining their degree. This year’s cortical scholar award was presented to Michelle M. Adams for her doctoral studies involving the hippocampus and issues of plasticity in response to estrogen status and aging. These studies have profound implications for estrogen replacement in post-menopausal women and our understanding of changes in plasticity of the aging brain. Her talk was entitled, ‘The Aging Synapse: Preservation of and Alterations in Synaptic Proteins’.

Michelle earned a bachelor of arts degree in psychology from the University of California at Davis in 1990. She then spent about six years in the Laboratory of Psychology and Psychopathology and the Laboratory of Neuropsychology at the National Institutes of Health in Bethesda, Maryland. She worked with Dr Leslie Ungerleider, a former Krieg Cortical Kudos Discoverer Awardee, where she analyzed the monkey visual system with neuroanatomical and behavioral methods. In 1996, she decided to pursue graduate studies at Mount Sinai School of Medicine under the direction of Dr John Morrison (President-elect of the Cajal Club, 2000–2002). She completed her degree in 2001 and has started a postdoctoral fellowship with Dr Mark Bear at Brown University in Rhode Island.

Michelle’s thesis advisor, Dr Morrison, wrote that her thesis took a ‘broad, multidisciplinary approach to a critically important set of questions’ and that her ‘productivity has been remarkable’. Michelle has five first-authored papers and one second-authored paper from her thesis work. This work involved N-methyl-d-aspartate (NMDA) receptor regulation by endocrine factors across puberty and senescence. Her findings offer compelling and conclusive evidence that NMDA receptors in the hippocampus are more responsive to chronological age than they are to endocrine status. This observation is a surprising and important result with respect to the controversy surrounding estrogen/NMDA receptor interactions in the context of memory changes associated with menopause. In another study, Michelle found that NMDA receptor levels in one particular circuit in the hippocampus correlate with memory performance regardless of the age of the animal. In addition, Michelle has studied the electron microscopic localization of NMDA receptors at spines. In these latter studies, she showed that estrogen induced an increase in axospinous synapse density in young animals but the number of NR1 subunits per synapse remained unchanged in these rats. She also showed that estrogen replacement in aged female rats failed to increase axospinous synapse density. However, this estrogen treatment in aged rats caused an up-regulation of NR1 subunits per synapse compared with aged rats with no estrogen. She concluded that the hippocampus from young and aged rats display different reactions to estrogen. Thus, the aged animals were unable to mount a plasticity response that could generate additional synapses while they were able to respond with increases in NMDA receptor subunits per synapse.

It needs to be noted that Michelle Adams has won other awards. She was a recipient of a James S. McDowell Fellowship in Cognitive Neuroscience in 1997 and a Graduate School Service Award from the Mount Sinai School of Biological Sciences in 2001. She also has participated in annual meetings of the Society for Neuroscience and has presented seminars at universities both in the United States and Europe. It is clear that Michelle has a promising career in neuroscience.

Conclusion

Over the past 15 years, the Cajal Club has honored outstanding neuroscientists for their research studies of the cerebral cortex and/or its connections at its annual meeting. These awards are funded by a generous donation from the late Dr Wendell J. Krieg, the first president of the Cajal Club, and his wife, Roberta. Wendell was a distinguished neuroanatomist and had a great reverence and respect for the work of Ramón y Cajal on the nervous system. The proceeds from the Kriegs’ bequest were designated to fund the Krieg Cortical Kudos, awards for talented neuroscientists who have made significant contributions to understanding the organization, function and development of the cerebral cortex. The awards are presented at the Cajal Club meetings that are held in conjunction with the American Association of Anatomists at the Annual Experimental Biology Meeting. This awards program is unique in that it recognizes research excellence at three levels of achievement. Special names were assigned to each of these levels by Dr. Krieg and in so doing researchers could be rewarded throughout their careers for contributions to our understanding of the cerebral cortex.

Notes

Address correspondence to Dr Charles E. Ribak, Department of Anatomy and Neurobiology, University of California, College of Medicine, Irvine, CA 92697-1275, USA. Email: ceribak@uci.edu

Figure 1.

From left to right are the recipients of the 2002 Krieg Cortical Kudos Awards (Thomas Woolsey, László Acsády, Michelle Adams, David Van Essen and Gábor Tamás) and the President of the Cajal Club (Charles Ribak).

Figure 1.

From left to right are the recipients of the 2002 Krieg Cortical Kudos Awards (Thomas Woolsey, László Acsády, Michelle Adams, David Van Essen and Gábor Tamás) and the President of the Cajal Club (Charles Ribak).

References

Acsády L, Kamondi A, Sik A, Freund T, Buzsáki G (
1998
) GABAergic cells are the major postsynaptic targets of mossy fibers in the rat hippocampus.
J Neurosci
 
18
:
3386
–3403.
Tamás G, Buhl EH, Lörincz A, Somogyi P (
2000
) Proximally targeted GABAergic synapses and gap junctions synchronize cortical inter-neurons.
Nat Neurosci
 
3
:
366
–371.
Van Essen DC, Felleman DJ, DeYoe EA, Olavarria J, Knierim J (
1990
) Modular and hierarchical organization of extrastriate visual cortex in the macaque monkey.
Cold Spring Harb Symp Quant Biol
 
55
:
679
–696.
Woolsey TA, Van der Loos H (
1970
) The structural organization of layer IV in the somatosensory region (SI) of mouse cerebral cortex. The description of a cortical field composed of discrete cytoarchitectonic units.
Brain Res
 
17
:
205
–242.