Presentation Details
| Odor-evoked activity outside canonical areas of olfactory information transmission is mapped by FosTrap and downregulated by diet-induced obesitydriven changes in metabolism Saptarsi Mitra1, 2, Franklin A.Pacheco1, Debra Ann Fadool1, 2, 3, . 1Department of Biological Science, Florida State University, Tallahassee, FL, USA.2Program In Neuroscience, Florida State University, Tallahassee, FL, USA.3Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, USA |
Abstract
The homeostatic pathways that are activated by odors to influence metabolic state and motivational aspects of feeding are incompletely known.We utilized Fos2A-iCreER mice (TRAP2) to permanently tag odor-evoked neuronal ensembles across the olfactory system, hypothalamus, and midbrain in both control fed (CF) and moderately-high fat fed (MHF) animals. We selected the odor isopropyl tiglate (IPT) because its preferred ligand (Olfr160) has previously been shown to be vulnerable to diet-induced obesity. Compared to vehicle [mineral oil] groups, IPT exposure resulted in differential TRAP labelling in the glomerular, mitral, and granule cell layer of the olfactory bulb (p <0.001); which extended to the anterior olfactory nucleus, piriform cortex, and cortical amygdala (p <0.05). In contrast, the paraventricular thalamus and preoptic area had no measurable changes in TRAP activity, reflecting specificity of the odor and also internal energy state of the animal. Interestingly, IPT robustly activated feeding-related nuclei in the hypothalamus, including the arcuate (ARC), dorsomedial (DMH), and lateral hypothalamus (LH) (p <0.001), while no change in TRAP activity was observed in stress sensing domains like the ventromedial hypothalamic nucleus and the suprachiasmatic nucleus (p > 0.05). Mice maintained on MHF diet exhibited a selective loss of odor-evoked ARC activity compared with CF animals (p <0.0001), whereas DMH and LH TRAP activity was unaffected (p > 0.05). While IPT activated the nucleus accumbens (NAc) and medial septum (MS) neurons in CF mice (p <0.01), it failed to do so in MHF animals (p > 0.05). Our study identified key brain regions linking chemosensation and metabolic state, and demonstrated an alteration in neural activity in hypothalamic areas upon obesogenic diet intervention.
No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.
No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.
Content Locked. Log into a registered attendee account to access this presentation.