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British Neuroscience Association Celebration Meeting
British Neuroscience Association Celebration Meeting
The Brain Research Association was established by that name in 1970, though its origins can be traced at least five years earlier. Over the years it has provided an important forum for the exchange of ideas and findings, and arguably provided a model for the American Neuroscience Foundation. It has been realized, however, that the original name does not ideally indicate the range of interests, and the organization has been relaunched as the British Neuroscience Association. To mark the change, and to review and celebrate past achievements, a one-day meeting was held on 1 October 1997 in the Wellcome Building in London.
The opening and welcoming remarks were by Professor Steven Rose, who recalled the beginnings of the Association as an informal group meeting in a pub. The activities were significantly boosted when Pat Wall returned from the USA in the late 1960s, partly because of his academic reputation and connections and also at a more mundane level because he could obtain funding.
The first major speaker was Professor Patrick Wall himself, introduced by a colleague as being responsible for the view that: "The brain is not hard-wired". This encapsulation of the viewpoint actually turned out to be an understatement, since the absence of hard-wiring extends at least to the sensory inputs to the spinal cord. The view that has traditionally been taken of sensory channels is not essentially different from that of Descartes, who postulated direct links (assumed by him to be mechanical) from primary sensors to the brain. The "phantom limb" phenomenon following amputation gives a first hint that the situation is not so simple. Some sort of phantom sensation might be expected simply because neurons deprived of input become extra-sensitive and will start to fire spontaneously, but the effect has too much structure to be accounted for in this way.
The history of the shift of viewpoint was recounted, with references to the contributions of many of the "big names" of neurophysiology. Experiments, mainly on rats, by the speaker have shown that the responses of receptors at the level of the inputs to the spinal cord are strongly influenced by descending pathways. The influence of these is not merely of the nature of gain control. Blocking the descending path can result in a radical change in the area of, say, skin, to which an input responds, and can alter the nature of the stimulus eliciting a response.
These considerations are particularly relevant to the study of pain mechanisms, and the phenomenon of inflammation, which follows even a minor injury, results from neural feedback. Apologizing for the pun, Wall said that the study of inflammation was currently a "hot topic" in neurology.
The presentation was rounded off by showing records of PET (positron emission tomography) scans showing the activity changes in a brain in response to a noxious stimulus. The picture differed greatly from what would be expected from the conventional view that sensory input is channelled through the sensory homunculus of the cerebral cortex. For a start, there were areas of the brain that were notable for a reduced, rather than increased, level of activity following the stimulus. Also, the area occupied by the sensory homunculus was hardly affected by the input, while changes were seen in the motor homunculus and cerebellum and other unexpected sites.
All the evidence supports the view that, if it is permissible to refer to an interface between direct sensory pathways and the mysterious processes of the brain, the interface is not at the sensory homunculus, nor anywhere in the brain as such, but has to be pushed back to at least the dorsal horns of the spinal cord.
The other main speaker in the morning session was Sir Andrew Huxley, joint author of the famous Hodgkin-Huxley model of neural transmission. This was developed between 1935 and 1952. It gives a very satisfactory physical model of the transmission of the nerve impulse, in terms of changes in membrane permeability to sodium and potassium ions, triggered by changes in potential difference across the membrane. Much of the experimental work was done on the "giant axon" of the squid which can be as large as a millimetre in diameter, but it is interesting that contributory evidence came from experiments on excitable cells in a kind of algae, and also on Lillie's "iron wire" model of nervous conduction.
The afternoon session began with two papers reviewing separate lines of investigation that have shown without doubt that nervous excitation at the synapse cannot be seen as a purely electrical phenomenon. Instead, it depends on highly specific transmitter substances. At one time it was widely believed that an adequate theory could assume electrical excitation, even though it was acknowledged that the electric charge was carried by interestingly complex ions. This view is enshrined in the model neurons of McCulloch and Pitts and in the recent developments in artificial neural nets following their lead. The first of the afternoon papers was by Professor Eric Barnard, who did much to establish molecular neuroscience. The second was by Dr Marianne Fillenz, one of whose contributions was to show how cells called astrocytes remove the excess of neurotransmitter substances.
After the tea break the speaker was Professor Horace Barlow who, in the 1950s, recorded with microelectrodes from single retinal elements, and also worked on stabilized retinal images. He interpreted findings on the frog eye in terms of the capability for controlling the strike of the tongue to catch insects. He appears, in fact, to have used the term "bugdetector" in this context before it was used by Lettvin et al. in reporting another well-known study. The title of his talk was: "Between the brain and the mind", and he referred to an unfortunate change of attitude over the years, such that physiological explanations of phenomena are now expected, with the result that the wrong questions are being asked about the mind. He advocated more attention to a functional viewpoint, in which for example the observations of Lorentz on animal behaviour and perception would be taken into account. His final message was: "Ask not what a mind is; ask what it does, and ask what a mind does in a community of brains, not when it is isolated".
The final speaker of the day was Professor Elizabeth Warrington, who has the remarkable distinction of having contributed significantly to neuroscience while also working as a clinician in the National Hospital for Diseases of the Nervous System. Her observations on fragmentation of images reproduced by certain brain-damaged patients were the basis of theories developed by David Marr. In her talk she described remarkable phenomena of selective amnesia such that, for example, some patients would recognize pictures of animate objects but not of inanimate ones, while for others the effect was reversed.
The summing-up was by Professor Steven Rose who expressed his appreciation of the intellectual feast that had been provided. Obviously, the separate contributions, though valuable in themselves, cannot easily be related to each other. Nevertheless, Professor Rose expressed his satisfaction that the new title of the organization is the British Neuroscience Association, with "Neuroscience" in the singular, expressing a conviction that the various approaches will converge.
European Brain Day
At a short session during the lunch break of the BNA meeting information was given about a planned European Brain Day on 18 March 1998. The initiative has been taken by The European Dana Alliance for the Brain (EDAB). Information was given by Professor Colin Blakemore, Chairman of the BNA and EDAB, and Elaine Snell, Executive Officer for EDAB. In a printed notice EDAB and the project are introduced as follows:
The European Dana Alliance for the Brain (EDAB) was established in January 1997 to raise public and political awareness of the importance of neuroscience and of disorders of the nervous system. A Declaration, including ten potentially achievable goals for brain research, has been signed by more than 60 leading neuroscientists from all over Europe, who have committed themselves to the objectives of EDAB. EDAB is modelled on a similar organization in the United States, the Dana Alliance for Brain Initiatives (DABI) which was founded in 1992.
Every year DABI, in partnership with the Society for Neuroscience, organises a week of public activities in the USA, entitled Brain Awareness Week. Next year, Brain Awareness Week will run from 15-21 March 1998. EDAB plans to extend Brain Awareness Week to Europe and collaborate with the British Association for the Advancement of Science during SET week. We will concentrate events on Wednesday 18 March, which is designated European Brain Day; a day of public activities related to the brain Europe-wide. This is an invitation to encourage you and your colleagues to plan activities on that day, and at any other time during Brain Awareness Week.
The kinds of activity suggested include Open Days for the public and the media in university departments and research institutions, visits by scientists to schools, lectures and debates for the public, and television and radio broadcasts. Further information, and at a later stage a "resource kit" can be obtained from Elaine Snell at EDAB. The address is 1 Park Square West, London NW1 4LJ. Tel: 0171 935 3748; Fax: 0171 935 0799; E-mail email@example.com
Alex M. Andrew
1. A brief report on the meeting appears on p. 1 of the British Neuroscience Association Newsletter, No. 30, Autumn/Winter 1997.