Research on autism has increased dramatically in the past decade, along with reported increased prevalence rates. A major emphasis of this research, based on recommendations from the Interagency Autism Coordinating Committee, and its strategic plan (http://www.iacc.hhs.gov/strategic-plan/2010/index.shtml) is on multidisciplinary, translational research focused on etiology and treatment. It is thus a difficult task to summarize, assimilate and interpret the ever-evolving findings regarding the etiology of autism(s). For starters, the seemingly most helpful finding in recent years has been that autism is actually not one disorder, but a constellation of similar behavioral phenotypes resulting from a common final pathway of multiple etiologies (and, therefore, neurochemical mechanisms). Growing knowledge that autism is actually “the autisms” (Geschwind & Levitt, Reference Geschwind and Levitt2007) underscores the complexity of providing the lay public, or even basic scientists, with a synopsis of research on diverse neurochemical findings, which may or may not relate to each other mechanistically.
The Neurochemical Basis of Autism is a well-written, succinct book that allows readers to become up to speed with current findings in neurobiology and neurochemistry of autism. The most compelling and refreshing aspect of this book is its exclusive focus on neurochemical mechanisms, as opposed to the larger field of autism etiology. While there have been several books on the biology of autism, none are recent and none focused specifically on the neurochemistry of autism. The content of this book shows that the field is still in the early phases of exploration but reminds us of the importance of getting to the endgame in etiology research, as neurochemical mechanisms are the true “why” behind the cascade of neural circuitry that goes awry and leads directly (or indirectly) to autism. While such a book is difficult to publish with respect to the fast-paced rate of findings in neurobiology and neurochemistry, the chapters in this volume are successful in summarizing the research thus far.
The book is not designed to cover all areas of neurochemistry, but to focus on particular underlying brain structures, neurotransmitter systems, and neurochemicals showing most promise with respect to autism. This volume first provides an introductory chapter that describes the clinical manifestations of autism. The following chapters describe theories and extant research on: the male prevalence; neuranatomical-behavioral correlates; minicolumns; developmental neuropathology; serotonin and GABA mechanisms; GABAergic activity; the 15q11-13 GABAA receptor genes; the cholinergic system; oxytocin; the noradrenergic system; oxidative stress; and neuroligins and neurexins. The book concludes with a chapter proposing a neurophysical chemistry model of autism from the perspective of Intelligence Modeling and a closing chapter that provides a summary of pharmacological treatments for autism and research on these treatments.
For the many psychologists, other “lay” professionals, and parents (those that are not basic neuroscientists) who may not be inclined to read about the details surrounding some of the basic neurochemistry of oxytocin or GABA receptors, for example, this book provides an answer. It contains a lay abstract summary section, which provides concise summaries of the purpose and main findings from each chapter. For those who are either prescribing medications or considering medications, the lay abstracts, and then at least some of the detailed chapters, may very well be one of the few places to go to for an understanding of why an autistic child of a certain age and with certain features (or genetic underpinnings) may be prescribed one medication and not another. This book also certainly provides clarity as to the reasons why medications do not yet exist that efficaciously treat the core features of autism.
One of the most important features of this volume is the singular focus on neurochemistry, with a context given to the broader cellular, molecular, and brain systems arenas. This book does not attempt to capture all research on potential biological etiologies of autism, but focuses on those areas that involve chemicals (mostly in the brain). The book also benefits from having chapter authors often representing experts not just in research specific to the application of certain fields to autism, but on the content areas themselves. This is particularly useful for the chapter on minicolumns. As the recent discovery that minicolumns (organization of cortical neurons) may be altered in the brains of individuals with autism has been groundbreaking, it is only in placing these findings into context of how minicolumns may be different in other disorders, as described in the chapter by Alan Peters, that readers can begin to get answers to questions that single journal articles do not attempt to answer, such as “is this finding specific to autism?” and “when in development does this occur?” and “what are the implications of minicolumn disorganization on synaptic and later brain development?”
The book veers from its detailed chapters providing summaries of specific research areas, with its chapter on intelligence modeling. In this chapter, an expert in intelligence modeling and cognitive dynamics spends much of the chapter outlining a description of these fields and how they have been applied more broadly in basic neuroscience, with final sections on how these areas may be applied specifically to autism. Three postulates are outlined, all relating to how neural systems failures (i.e., circuit breaker failure, inefficient processing/computational capacity, inadequate energy supply at a cellular level) “cause” autism symptomatology. Here, a lack of synthesis with specific research findings leaves this chapter mostly theoretical.
The main limitation of this book is that, although the preface very succinctly introduces the purpose and concepts to be described, there is no true summary chapter after the various chapters authored and written to focus on quite specific topics. Instead, the book concludes with a chapter that uses intelligence modeling to assist with “where to go” in neurochemical study (with aforementioned limitations), and a chapter reviewing the literature on pharmacology. While pharmacological treatment certainly is one end goal of neurochemical investigation of autism, a chapter that synthesizes findings from the various neurochemical domains would have been very helpful in putting forth postulates on where the most promise in techniques or areas may lie. Relatedly, although the book clearly benefits from not trying to provide a complete understanding of the field with respect to topics such as genetics, genomics, or imaging-genetics, readers who do not regularly read this literature may not appreciate the broader context of the specific topics described. A final chapter may also have used the broader context to emphasize caution to the reader regarding interpretation in findings, as replication of studies has been very difficult to achieve in the autism literature, and there may be even more caution needed with regard to translational studies that are trying to move from different species into human manifestations of autism (Insel, Reference Insel2010).
In conclusion, The Neurochemical Basis of Autism is a timely, coherent, and informative summary of research specifically addressing the state of the field in neurochemical mechanisms of action for autism etiology. It will be useful for anyone trying to understand where research currently stands regarding the when, why, and how questions of autism etiology.
