EXPLORING THE MIND WITH A MICROSCOPE: FREUD’S BEGINNINGS IN NEUROBIOLOGY Lazaros C. Triarhou University of Macedonia, Thessaloniki, Greece Abstract: Sigmund Freud (1856-1939), the acknowledged founder of psychoanalysis, started his research career as a promising neurobiologist. This article presents an overview of his early articles in neuroanatomy and a literature update regarding the awareness of Freud’s origins in neurobiology. In all, Freud invested a decade studying animal histology, cell biology and basic neuroscience before turning to human neuropsychiatric disorders. Through his histological studies, Freud provided coherent evidence supporting the neuron doctrine and suggesting that the protoplasm consists of a contractile fibrillary network, the present-day cytoskeleton. Freud also documented movements of nucleoli in neurons, a phe- nomenon presently referred to as nuclear rotation. In certain instances, Freud’s observa- tions antedate later views by more than half a century and are important to our under- standing of neuronal structure and intracellular motility. Key words: Freud, History of neuroscience, Neurohistology, Neuron theory. INTRODUCTION Whether one may agree (Edelman, 1992; Gabbard, 2004; Kandel, 2002) or dis- agree (Eissler, 1995; McCrone, 2004; Tallis, 1996) with Sigmund Freud’s proposi- tions on the functioning of the mental apparatus, it is a common admission that psychoanalytic theory has had a considerable impact on twentieth century scien- tific, intellectual and cultural thought. Freud as a psychologist is viewed as one of the greatest explorers of the human mind that ever lived (Gay, 1988; Panek, 2004). Acknowledgement : This article is based in part on an invited lecture given at the Conference on “Freud’s legacy in contemporary science” that was organized by the School of Psychology of Aristotle University of Thessaloniki and the Psychological Society of Northern Greece, November 10th, 2006. Address: Lazaros C. Triarhou, Department of Educational and Social Policy, School of Economic and Social Sciences, University of Macedonia, Egnatia 156, 540 06 Thessaloniki, Greece. E-mail: triarhou@uom.gr Hellenic Journal of Psychology, Vol. 6 (2009), pp. 1-13