TY - JOUR
T1 - α4βδ-GABAARs in the hippocampal CA1 as a biomarker for resilience to activity-based anorexia
AU - Aoki, C.
AU - Wable, G.
AU - Chowdhury, T. G.
AU - Sabaliauskas, N. A.
AU - Laurino, K.
AU - Barbarich-Marsteller, N. C.
N1 - Funding Information:
We are grateful to Barry Cohen for helpful discussions on statistical analyses. We thank Anna Rita Colacino Ficarrotta, Kei Tateyama, Jia-Yi Wang and Alisa Liu for their technical assistance. This study was supported by the following grants: The Klarman Foundation Grant Program in Eating Disorders Research to C.A. and N.B.M.; National Institutes for Health Grants R21MH091445-01 to C.A. and N.B.M., R01NS066019-01A1 to C.A., R01NS047557-07A1 to C.A., N.E.I. Core Grant EY13079 to C.A., R25GM097634-01 to C.A.; UL1 TR000038 from the National Center for the Advancement of Translational Science (NCATS) to T.G.C.; NIMH Training Program in Systems and Integrative Neuroscience T32 MH019524 to G.W.; NYU’s Research Challenge Fund to C.A.; NYU Dean’s Undergraduate Research Fund to Alisa Liu and J.-Y. Wang.
PY - 2014/4/18
Y1 - 2014/4/18
N2 - Anorexia nervosa (AN) is a psychiatric illness characterized by restricted eating and an intense fear of gaining weight. Most individuals with AN are females, diagnosed first during adolescence, 40-80% of whom exhibit excessive exercise, and an equally high number with a history of anxiety disorder. We sought to determine the cellular basis for individual differences in AN vulnerability by using an animal model, activity-based anorexia (ABA), that is induced by combining food restriction (FR) with access to a running wheel that allows voluntary exercise. Previously, we showed that by the fourth day of FR, the ABA group of adolescent female rats exhibit >500% greater levels of non-synaptic α4βδ-GABAARs at the plasma membrane of hippocampal CA1 pyramidal cell spines, relative to the levels found in age-matched controls that are not FR and without wheel access. Here, we show that the ABA group exhibits individual differences in body weight loss, with some losing nearly 30%, while others lose only 15%. The individual differences in weight loss are ascribable to individual differences in wheel activity that both precedes and concurs with days of FR. Moreover, the increase in activity during FR correlates strongly and negatively with α4βδ-GABAAR levels (R=-0.9, p<0.01). This negative correlation is evident within 2days of FR, before body weight loss approaches life-threatening levels for any individual. These findings suggest that increased shunting inhibition by α4βδ-GABAARs in spines of CA1 pyramidal neurons may participate in the protection against the ABA-inducing environmental factors of severe weight loss by suppressing excitability of the CA1 pyramidal neurons which, in turn, is related indirectly to suppression of excessive exercise. The data also indicate that, although exercise has many health benefits, it can be maladaptive to individuals with low levels of α4βδ-GABAARs in the CA1, particularly when combined with FR.
AB - Anorexia nervosa (AN) is a psychiatric illness characterized by restricted eating and an intense fear of gaining weight. Most individuals with AN are females, diagnosed first during adolescence, 40-80% of whom exhibit excessive exercise, and an equally high number with a history of anxiety disorder. We sought to determine the cellular basis for individual differences in AN vulnerability by using an animal model, activity-based anorexia (ABA), that is induced by combining food restriction (FR) with access to a running wheel that allows voluntary exercise. Previously, we showed that by the fourth day of FR, the ABA group of adolescent female rats exhibit >500% greater levels of non-synaptic α4βδ-GABAARs at the plasma membrane of hippocampal CA1 pyramidal cell spines, relative to the levels found in age-matched controls that are not FR and without wheel access. Here, we show that the ABA group exhibits individual differences in body weight loss, with some losing nearly 30%, while others lose only 15%. The individual differences in weight loss are ascribable to individual differences in wheel activity that both precedes and concurs with days of FR. Moreover, the increase in activity during FR correlates strongly and negatively with α4βδ-GABAAR levels (R=-0.9, p<0.01). This negative correlation is evident within 2days of FR, before body weight loss approaches life-threatening levels for any individual. These findings suggest that increased shunting inhibition by α4βδ-GABAARs in spines of CA1 pyramidal neurons may participate in the protection against the ABA-inducing environmental factors of severe weight loss by suppressing excitability of the CA1 pyramidal neurons which, in turn, is related indirectly to suppression of excessive exercise. The data also indicate that, although exercise has many health benefits, it can be maladaptive to individuals with low levels of α4βδ-GABAARs in the CA1, particularly when combined with FR.
KW - Adolescence
KW - Alpha4-GABA-receptor
KW - Anxiety
KW - Hippocampus
KW - Neuromodulation
KW - Stress
UR - http://www.scopus.com/inward/record.url?scp=84896701176&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84896701176&partnerID=8YFLogxK
U2 - 10.1016/j.neuroscience.2014.01.011
DO - 10.1016/j.neuroscience.2014.01.011
M3 - Article
C2 - 24444828
AN - SCOPUS:84896701176
SN - 0306-4522
VL - 265
SP - 108
EP - 123
JO - Neuroscience
JF - Neuroscience
ER -