A Journey to Remember

Home , Yadin Dudai

NATURE|Vol 441|11 May 2006 SPRING BOOKS basis for a great story. But The Jasons rings syndrome is not confined to hostages who difference in complexity and the likelihood of few dramatic bells. And the author observes: become enamoured of their captors: it can emergent properties, it is unlikely that probing “Jasons think they’ve done the country good, also afflict observers who fall for their sub- the ganglia of Aplysia can tell us how our brain but they haven’t got much clear evidence.” jects. As Finkbeiner wrote of an anonymous recalls our first love or our father’s face. Perhaps a more sceptical attitude towards Jason identified only as “Dr. Y”: “She might Nevertheless, the reductionist approach to the Jasons in particular and the advisory pro- look plain if she didn’t move so gracefully, behavioural plasticity, of which Kandel’s work cess in general would have paid off. My own and if she didn’t sit so quietly, self-possessed is the prime example, is a success story that has observation is that politicians seek scientific and intense and honest to the bone.” ■ given us models of molecular and cellular plas- advice to support their preconceptions, not Daniel S. Greenberg is a journalist in ticity that propose how experience affects to steer them to wisdom. But where secrecy Washington. His new book, Science for Sale, will nerve cells. It is now for those who follow previously obscured public view of the Jasons, be published next year by the University of Kandel to link the molecular and cellular level reverence is the problem here. Stockholm Chicago Press. with the systems level of analysis. This integra- tion is the major challenge facing the science of memory, and might require, in addition to new methodologies, a change of zeitgeist or an amalgamation of approaches. A journey to remember Kandel’s book is enthusiastically recom- mended as a captivating account of the career In Search of Memory: The Emergence of a events in their investigators. Even if such an of a prominent leader in contemporary neuro- New Science of Mind inclusive definition is accepted, the distinction science. The author is not only an authorita- by Eric R. Kandel should still be made between memory as a tive scholar but also a marvellous popularizer W. W. Norton: 2006. 510 pp. $29.95 process and as an item with mental content. and narrator, who brings to the story an The process is assumed to be subserved by attractive mix of facts, personal touches and Yadin Dudai the plasticity of synapses, the functional con- wisdom, seasoned with reflective humour. Few can interlace their autobiography with the tacts between nerve cells. One could further But In Search of Memory is not just about evolution of a scientific paradigm. Even fewer assume that the basic building blocks of the science: it is also about history and identity. can weave such a story seamlessly. Eric Kandel plasticity machinery were conserved in evolu- Kandel is a devoted scientist, humanist, is one of these. His career, from his training in tion. If this is the case, why not approach family man and proud Jew. He follows, by his Harry Grundfest’s laboratory at Columbia memory by studying its simplest forms in the own definition, the “Talmudic tradition writ University in New York more than fifty years simplest of organisms? This philosophy has large. But rather than annotate a religious ago to a remarkably productive present, also guided Kandel and given the timid sea-slug text, we annotate texts written by evolutionary at Columbia, epitomizes his ardent reduction- Aplysia a prominent position in textbooks of processes working over hundreds of millions ist approach to the neural sciences. Its formal neuroscience. The approach, anchored in the of years.” pinnacle was the Nobel Prize in Physiology or achievements of molecular biology, has proved Kandel was just a child when he emigrated Medicine, which Kandel shared in 2000 with highly productive in identifying plasticity from Austria to the United States, but the Arvid Carlsson and Paul Greengard for their mechanisms that subserve memory. What it Holocaust and the trauma of European Jewry discoveries concerning signal transduction in doesn’t address satisfactorily is the content and are deeply embedded in his memory. His the nervous system. meaning of memory items. This requires an contempt for racism is clear. In the back- Kandel’s intellectual journey in neuro- understanding of how brains encode specific ground hovers the terrible awareness that science can be traced back to his first pieces of mental information. Many would many of his generation perished, unknown, encounter with Grundfest. The enthusiastic argue that this calls for the spatiotemporal in concentration camps before they had a medical student, with a strong background in codes of neuronal populations to chance to explore and contribute to the world. history and literature, proposes unveiling the be deciphered. Further- When the Austrian president contacts Kandel brain substrates of Freud’s three psychic struc- more, given the and expresses his desire to honour the new tures, the ego, superego and id, in six months. immense Nobel laureate of Viennese origin, Kandel’s Grundfest, the seasoned professor of neurol- reaction is to organize a symposium in ogy, suggests a different agenda, no less Vienna to acknowledge Austria’s central grandiose: to understand the mind, he role in the Nazi atrocities and evaluate replies, we need to look at the the significance for scholarship of the brain one cell at a time. The disappearance of the Jewish commu- narrative of the brain sci- nity in Vienna. Kandel’s accounts of ences in the past century incidents during this visit to Vienna is made up of attempts to should be read carefully by those who negotiate between these two ignore lingering undercurrents of extremes. In his admirable per- anti-Semitism. sonal version of this narrative, The Greek poet Constantine Cavafy, Kandel is still a grundfestian, but in his poem Ithaka, which recounts the appreciates that the bottom-up return of Odysseus to his homeland, approach still has a long way to go. advises his hero not to hasten: Nowhere, perhaps, is this conflict As you set out for Ithaka, between reductionism and global Hope the voyage is long, approaches to the brain more evident Full of adventure, full of discovery… than in memory research. Memory is a Better if it lasts for years… term applied nowadays to a wide gamut Ithaka gave you the marvellous of functions, ranging from experience- journey dependent modification of reflexes in brain- Without her you would not have less organisms to the recollection of personal sailed away.

The reward, according to Cavafy, is the If the goal is to chart and analyse plasticity concerns with biodiversity loss and his contri- journey, rather than the goal. Both the young in neuronal terrain in fine detail, then the butions to the development of the fledgling Kandel who met Grundfest and the mature, kandelian Aplysia paradigm is a tremendous field of environmental ethics. imaginative investigator of the Aplysia epoch leap forwards. If it is to understand how recol- Each article is preceded by a brief essay in seem to have valued the goal at least as much lecting humans think, feel and plan, we might which Wilson explains its context and outlines as the journey. But reading these memoirs, one need more Kandels. ■ more recent developments in the field. senses that, over the years, Kandel’s apprecia- Yadin Dudai is in the Department of Although not as thorough and telling as tion of the journey itself has increased. Is Neurobiology, Weizmann Institute of Science, those by W. D. Hamilton in Narrow Roads of Ithaka attainable for those who study memory? Rehovot 76100, Israel. Gene Land, vols 1–3 (Oxford University Press, 1997–2005), these brief essays are interesting and informative about some essentials of Wil- son’s personality. For example, Wilson explains that he revised the ant genus Pheidole as “a The ant trail hobby, a form of relaxation” during which he “listened to classical and soft rock music…at Nature Revealed: Selected Writings, 1959 and 1962 he published a few specialized odd hours” in his home laboratory. The out- 1949–2006 papers detailing the nature of communication come was Pheidole in the New World (Harvard by Edward O. Wilson within ant societies. By 1963 he had realized University Press, 2003), an 800-page mono- Johns Hopkins University Press: 2006. that pheromones were important, and had graph with more than 5,000 drawings and a list 736 pp. $35 ventured to propose general principles in a of 624 species, of which 337 are new to science Scientific American article entitled simply (see Nature 424, 727; 2003) — an achievement Laurent Keller “Pheromones”. In this piece, Wilson also spec- beyond what most scientists would ever dream Edward O. Wilson is one of the most distin- ulated for the first time on the existence of of accomplishing in a lifetime. guished scientists and thinkers of our time. He human pheromones. On the basis of data by Nature Revealed contains all 60 articles in is best known for his twenty or so books, French biologist J. LeMagnen, who showed their original form. Unfortunately, the size exploring topics as diverse as sociobiology, that the odour of exaltolide can only be per- reduction of several articles resulted in print so human nature, ant taxonomy, biodiversity and ceived clearly by sexually mature women at small as to be reminiscent of the labels on the philosophy of knowledge, but he has also the time of ovulation, Wilson stated that insect museum specimens. The diversity and published a large number of scientific articles although these observations “hardly represent technical nature of some of the articles might and other works. Nature Revealed, a compila- a case for the existence of human phero- make this book difficult to read from cover to tion of 60 of these articles, illustrates how his mones…they do suggest that the relation of cover, but it remains a treasure for those interest has ranged between fields as diverse as odours to human physiology can bear further interested in science and history. The progres- entomology, ethology and philosophy. examinations”. Such examinations did indeed sion of articles highlights the path of Wilson’s Wilson’s first publication was in 1949 in a reveal that pheromones are implicated in journey across different disciplines in an local journal called Alabama Conservation. In some human behaviours. attempt to bridge gaps between them, includ- this paper, Wilson, then a 19-year-old senior at In the same vein, the sequence of publica- ing the gulf between the humanities and the the University of Alabama, reports the distrib- tions reveals the steps that led Wilson from sciences. These are important messages in ution of what was then called the imported fire reports of patchy ant distributions in the rain- this age of ultraspecialization and disciplinary ant. His second article was published in Evolu- forests of New Guinea to the synthesis with compartmentalization. ■ tion, an influential scientific journal. In this Robert MacArthur of the influential theory of Laurent Keller is in the Department of Ecology article Wilson reports that there are two pheno- island biogeography. Similarly, the content of and Evolution, Biophore, University of Lausanne, typic variants of the imported fire ant. By several articles demonstrates Wilson’s growing Lausanne 1015, Switzerland. switching queens from one colour-type colony to the other, he proved a hereditary basis for the phenotypic differences observed and pro- posed several explanations for how one morph replaced the other. Incidentally, later studies revealed that the two colour morphs are actually two distinct species, now called the black imported fire ant (Solenopsis richteri) and the red imported fire ant (Solenopsis invicta), the latter of which has become one of the worst invasive pest species in the world. The difference in the content of these two articles foreshadows Wilson’s main gift: his ability to be hugely integrative and make bold syntheses. In the scant two years that separated the publication of these two reports, Wilson had vastly broadened his interests, allowing him to interpret his field observations within a solid framework of evolutionary biology and population genetics. The progression of articles in Nature Revealed demonstrates, again and again, Wil- son’s endless capacity to put scientific findings into a broader context and to bridge gaps between disciplines. For example, between