Neuroanatomy of romantic love and nerve growth factor as a love painkiller

Abstract

Romantic love, a universal, cross-cultural phenomenon, has been a focus of attention and theme of research for neuroscientists. Romantic love involves a collection of activities associated with the acquisition and retention of emotions. It is also characterized by distinct physiological hormonal changes and psychological behaviours. Technologic advancements in neuroimaging have led to the identification of specific brain areas related to the genesis of love. Recent studies showed that the activated areas during love include cortex, medial insula, ante­rior cingulate, hippocampus, and nucleus accumbens. These regions are also parts of the brain reward system, which makes love a reward experience. Some other regions are deactivated during love and these include amyg­dala, frontal cortex, prefrontal cortex, and middle temporal cortex. Deactivation of the amygdala may be relat­ed to reduced fear response and inhibition of xenophobia, whereas deactivation of the frontal cortex may reduce negative emotions and judgement. Interestingly, these deactivations are lateralized to the right side. In terms of neuroanatomy, there are some differences between maternal love and romantic love. The hypothalamus - linked to sexual arousal - is active in romantic love as compared to maternal love. Another neural substrate is the left dorsal anterior cingulate cortex, which seems active during watching photographs of a romantic partner. Apart from neuroimaging studies, investigating hormone profile may provide clues about the brain areas of love. For instance, circulating levels of nerve growth factor (NGF) are increased among subjects in love. NGF affects senso­ry neurons and provides better pain control, which makes it a love painkiller.