The Antinarcolepsy Drug Modafinil Reverses Hypoglycemia Unawareness and Normalizes Glucose Sensing of Orexin Neurons in Male Mice

Document Type

Article

Publication Date

8-1-2023

Abstract

Perifornical hypothalamus (PFH) orexin glucose-inhib-ited (GI) neurons that facilitate arousal have been impli-cated in hypoglycemia awareness. Mice lacking orexin exhibit narcolepsy, and orexin mediates the effect of the antinarcolepsy drug modafinil. Thus, hypoglycemia awareness may require a certain level of arousal for awareness of the sympathetic symptoms of hypoglycemia (e.g., trem-ors, anxiety). Recurrent hypoglycemia (RH) causes hypoglycemia unawareness. We hypothesize that RH impairs the glucose sensitivity of PFH orexin GI neurons and that modafinil normalizes glucose sensitivity of these neurons and restores hypoglycemia awareness after RH. Using patch-clamp recording, we found that RH enhanced glucose inhibition of PFH orexin GI neurons in male mice, thereby blunting activation of these neurons in low-glucose conditions. We then used a modified conditioned place preference behavioral test to demonstrate that mod-afinil reversed hypoglycemia unawareness in male mice after RH. Similarly, modafinil restored normal glucose sensitivity to PFH orexin GI neurons. We conclude that impaired glucose sensitivity of PFH orexin GI neurons plays a role in hypoglycemia unawareness and that normalizing their glucose sensitivity after RH is associated with resto-ration of hypoglycemia awareness. This suggests that the glucose sensitivity of PFH orexin GI neurons is a therapeu-tic target for preventing hypoglycemia unawareness.

Identifier

85165521559 (Scopus)

Publication Title

Diabetes

External Full Text Location

https://doi.org/10.2337/db22-0639

e-ISSN

1939327X

ISSN

00121797

PubMed ID

36525384

First Page

1144

Last Page

1153

Issue

8

Volume

72

Grant

1 R01 DK103676-01A1

Fund Ref

National Institutes of Health

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