The Amygdaloid Body as the Anatomical Substrate of Emotional Memory: Implications in Health and Disease

Abstract

The Amygdaloid Body is a heterogeneous nuclear complex that establishes extensive connections with numerous structures of the limbic system, the thalamus, the brainstem, and the neocortex, and constitutes the focal center of its widespread three-dimensional white matter chassis. Since the 50s, the neurophysiological observations of Wilder Penfield et al. began to clarify the role of the AB in human memory. More recently, the introductions of a more advanced neuroimaging technology (PET, fMRI, DTI) led to a growing awareness of its crucial implications in the etiology of a variety of neuropsychiatric disorders, such as trauma spectrum and mood spectrum disorders. Additionally, the AB and its connections have been successfully used as a target for Deep Brain Stimulation (DBS) in the treatment of refractory forms of psychiatric disorders, especially trauma spectrum disorders. Therefore, gaining a deeper understanding of the morphophysiology of the AB has increasingly become utmost relevance for neuroscientists and clinicians alike. With the present chapter, we attempt to provide an exhaustive description of the functional anatomy of the AB, hopefully providing a useful tool for the approach to the anatomical substrates of the emotional components of memory and learning and to their role in the phenomenology and treatment of neuropsychiatric disorders.