Using Awake Animal Imaging to Understand Neural Circuits of Emotion: Studies Ranging from Maternal Care to Aggression

摘要

Non-invasive, functional magnetic resonance imaging in awake animals gives new insight into the organization of neural circuits involved in behavior associated with intense emotional reactions. The rewarding aspects of breast feeding or the aversive threatening feelings when confronted with a live predator are just two examples of the types of provocation paradigms that can be staged in the magnet during an imaging session. When combined with the use of 3D segmented, annotated brain atlases and computational analysis, it is possible to reconstruct distributed, integrated neural circuits or "fingerprints" of brain activity that reflect emotional and cognitive states. In many cases these neural circuits are similar to those identified in human brain imaging studies, with homologous neural substrates subserving similar functions. While these imaging data cannot tell us how an animal feels, the patterns of brain activity across a range of positive and negative provocation paradigms always include the limbic cortex, basal ganglia and hippocampus. These areas are involved in the integration and processing of information related to the emotional experience and motivation necessary for approach/avoidance behavior.