Outline Studies in Biology Brain Biochemistry

The underlying chemical connections of the nerve cell are de­ chemical processes cannot be discussed or seen pendent upon special morphological features: in perspective without constant awareness of synaptic contact is mediated by chemical mol­ related aspects of physiology and morphology. The brain is the most complex and highly of semi-permeable excitable membranes which specialised of all mammalian organs. Under­ can be caused, rapidly and transiently, to under­ standing the complexity of its function remains go changes in permeability to small chemical man's greatest challenge. The functional unit is molecules and to cations. The highly specialised the neurone, or excitable nerve cell, making ana­ nature of the constituent cells, with their unique tomical and chemical connections with other function and specificity, is c10sely related to units in the system. Many of the essential bio­ the structure of the whole tissue. The underlying chemical connections of the nerve cell are de­ chemical processes cannot be discussed or seen pendent upon special morphological features: in perspective without constant awareness of synaptic contact is mediated by chemical mol­ related aspects of physiology and morphology. ecules, 'neuro-transmitters' which ensure the The hrain is structurally extraordinarily com­ continued propagation of electrical impulses plex in its distinct anatomical regions, each of through sequential units of the system. Also which is heterogeneous in the types and struc­ c10sely related to the morphology of the ner­ tures of the constituent cells. vous system is the chemical energy expended in One aspect of the biochemical function of maintaining distribution gradients of cations the brain can be seen in its efficient production across cellular membranes. Chemical neuro­ of the energy required to support the unique pro­ transmission results in an alteration in cation cesses referred to above.

The student of biological science in his final years as an undergraduate and his first years as a graduate is expected to gain some familiarity with current research at the frontiers of his discipline. New research work is published in a perplexing diversity of publications and is inevitably concerned with the minutiae of the subject. The sheer number of research journals and papers also causes confusion and difficulties of assimilation. Review articles usually presuppose a back ground knowledge of the field and are inevitably rather restricted in scope. There is thus a need for short but authoritative introductions to those areas of modern biological research which are either not dealt with in standard introductory textbooks or are not dealt with in suffi cient detail to enable the student to go on from them to read scholarly reviews with profit. This series of books is designed to satisfy this need. The authors have been asked to produce a brief outline of their subject assuming that their readers will have read and remembered much of a standard introductory textbook on biology. This outline then sets out to provide by building on this basis, the conceptual framework within which modern research work is progressing and aims to give the reader an indication of the problems, both conceptual and practical, which must be overcome if progress is to be maintained.