Neuroendocrinology and Brain Imaging

Received: 3 December 2020 | Accepted: 3 December 2020 DOI: 10.1111/jne.12927

EDITORIAL

Neuroendocrinology and brain imaging

Human brain imaging is now a well-established technique for de- individual's behavioural adjustment in cognitive control. They ciphering neural processes in psychology, neuroscience, psychiatry provide evidence that pupil dilation can be used as a potential and other diverse biomedical fields. However, until now, the use external marker for endogenous neural processes involved in of these techniques in the field of neuroendocrinology has been optimising behavioural control. Later onset of puberty has been limited. associated with a lower BMI in adulthood independent of child- The articles in this special issue are based on research presented hood BMI. However, how the relationship between time of onset at the first "Neuroendocrinology and Brain Imaging" symposium of puberty and BMI in adulthood is associated with neurocogni- held in Rome in June 2019 as a satellite event to the Human Brain tive outcomes is largely unstudied. Based on data from the Human Imaging meeting, the largest meeting related to brain imaging world- Connectome Project, Shearrer et al6 investigated the effect of age wide. Presentations at the meeting targeted different aspects in- at onset of menstruation and BMI, as well as their interaction, on cluding brain morphology and function. brain functional correlation. They provide evidence that the inter- Brain morphological changes in grey and white matter occur action between age at onset of menstruation and BMI at scan was across the whole lifespan; however, metabolic changes can also af- associated with stronger correlation between the somatosensory fect brain morphology. Shin et al1, Garcia-Garcia et al2 and Kullmann and visual network, and the visual network and cingulo-opercu- et al3 implemented quantitative magnetic resonance imaging (MRI) lar task control network. Melkonyan et al7 report that intranasal measures to investigate the effect of obesity on brain structure. Shin oxytocin did not affect the motivational behaviour to food in an et al1 show, in a sample of 533 adult participants (aged 36-65 years), approach-avoidance task. how adiposity-related insulin resistance is associated with thickness The diversity of papers presented in this special issue clearly of the human cerebral cortex. Females older than 50 years of age illustrate that human brain imaging is an evolving field in neuro- revealed lower cortical thickness with increasing adiposity/insulin endocrinology. However, it should also be stressed that further dis- resistance. However, this relationship was not identified in males or cussions are necessary to clearly develop a strategy to address the younger females. In a meta-analysis, Garcia-Garcia et al2 show that integration of brain imaging, behaviour and neuroendocrinology. the volume of the nucleus accumbens, a possible key region for the pathophysiology of obesity, exhibits age dependent differences in AUTHOR CONTRIBUTIONS relation to body mass index (eg, an increase in volume in younger Hubert Preissl: Conceptualisation; Writing – original draft; subjects and a decrease in older participants). The negative correla- Writing – review & editing. tion in older participants may also be related to inflammatory processes, which was further investigated by Kullmann et al.3 Proton Peer Review density, a quantitative marker for inflammatory processes, was pos- The peer review history for this article is available at https://publo itively correlated with body mass index (BMI) independent of age in ns.com/publon/10.1111/jne.12927. several brain regions, and particularly in the hypothalamus. These studies provide a starting point for further applications of quantita- Hubert Preissl1 tive MRI in relation to obesity and neuroendocrinological processes. Dana Small2 Besides brain structure, obesity strongly alters brain function Stephanie Kullmann1 including neurotransmission. New research reveals how dopamine and oxytocin influence eating behaviour and the develop- 1Institute for Diabetes Research and Metabolic Diseases of the ment and maintenance of obesity. Hartmann et al4 show that Helmholtz Center Munich at the University of Tübingen, German dopamine depletion leads to a worse memory performance in Center for Diabetes Research (DZD e.V.), Tübingen, Germany participants with low habitual intake of a diet high in saturated 2Modern Diet and Physiology Research Center, Department of fat and refined sugars. In addition, they found that participants Psychiatry, Yale University, New Haven, CT, USA with high habitual intake had a significantly higher peripheral dopamine precursor availability. In a functional MRI and pupil dila- Correspondence tion study, Grueschow et al5 show that the functional coupling Hubert Preissl, PhD, Institute for Diabetes Research and between the locus coeruleus-noradrenergic arousal system and Metabolic Diseases (IDM) of the Helmholtz Center Munich the dorsomedial/lateral prefrontal cortex is associated with the at the University of Tübinge Otfried-Müller-Straße 47,

D-72076 Tübingen, Germany. Phone: +49-7071-2987704. 3. Kullmann S, Abbas Z, Machann J, et al. Investigating obesity-associated brain inflammation using quantitative water content mapping. J Fax: +49-7071-295706. Neuroendocrinol. 2020;32:e12907. Email: [email protected] 4. Hartmann H, Pauli LK, Janssen LK, Huhn S, Ceglarek U, Horstmann A. Preliminary evidence for an association between intake of high-fat ORCID high-sugar diet, variations in peripheral dopamine precursor availabil- Hubert Preissl https://orcid.org/0000-0002-8859-4661 ity and dopamine-dependent cognition in humans. J Neuroendocrinol. 2020;32:e12917. 5. Grueschow M, Kleim B, Ruff CC. Role of the locus coeruleus arousal REFERENCES system in cognitive control. J Neuroendocrinol. 2020;32:e12890. 1. Shin J, Pelletier S, Richer L, et al. Adiposity-related insulin resis- 6. Shearrer GE, Sadler JR, Papantoni A, Burger KS. Earlier onset of men- tance and thickness of the cerebral cortex in middle-aged adults. J struation is related to increased body mass index in adulthood and Neuroendocrinol. 2020;32:e12921. altered functional correlations between visual, task control and so- 2. García-García I, Morys F, Dagher A. Nucleus accumbens vol- matosensory brain networks. J Neuroendocrinol. 2020;32:e12891. ume is related to obesity measures in an agedependent fashion. J 7. Melkonyan A, Liu L, Brown EC, et al. Unchanged food approach-avoid- Neuroendocrinol. 2019;32:e12812. ance behaviour of healthy men after oxytocin administration. J Neuroendocrinol. 2020:e12923.