Presentation Details
| Neural Control of Tongue Blood Flow by Brainstem Parasympathetic Circuits During Orofacial Behaviors Jun Takatoh, Bin Chen, Aya Miyazaki. Stony Brook University, Department of Neurobiology and Behavior, Stony Brook, NY, USA |
Abstract
Eating demands intense and sustained tongue activity, necessitating coordination between motor output and vascular regulation. Unlike most skeletal muscles, whose blood flow is regulated primarily by sympathetic autonomic inputs during exercise, the tongue receives dual sympathetic and parasympathetic innervation, suggesting distinct mechanisms of blood flow regulation. How these mechanisms operate during parasympathetic-dominant eating behavior remains poorly understood. Using cell-type-specific viral tracing in mice, we identified a parasympathetic circuit originating in the superior salivatory nucleus (SSN), a parasympathetic brainstem nucleus, that forms monosynaptic projections to tongue-resident parasympathetic neurons (intralingual parasympathetic neurons, ILPNs) innervating the tongue vasculature. Immediate early gene expression analysis showed that both SSN neurons and ILPNs are recruited during licking, consistent with engagement of this circuit during oral motor function. To assess functional relevance, we combined circuit-specific chemogenetic manipulation with laser speckle imaging of the tongue in anesthetized animals and found that selective activation of SSN neurons robustly increases tongue blood flow. In behaving, head-restrained animals, activation of this pathway increased licking amplitude, linking parasympathetic circuit activity to vascular and motor aspects of oral behavior. Together, these results identify a brainstem parasympathetic circuit that regulates tongue blood flow during orofacial behavior and suggest that intralingual parasympathetic neurons (ILPNs) serve as a tongue-resident interface through which central autonomic activity coordinates local vascular physiology with oral motor behavior.
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.