Distinct Neuronal Projections From the Hypothalamic Ventromedial Nucleus Mediate Glycemic and Behavioral Effects.
Diabetes
; 67(12): 2518-2529, 2018 12.
Article
en En
| MEDLINE
| ID: mdl-30257978
ABSTRACT
The hypothalamic ventromedial nucleus (VMN) is implicated both in autonomic control of blood glucose and in behaviors including fear and aggression, but whether these divergent effects involve the same or distinct neuronal subsets and their projections is unknown. To address this question, we used an optogenetic approach to selectively activate the subset of VMN neurons that express neuronal nitric oxide synthase 1 (VMNNOS1 neurons) implicated in glucose counterregulation. We found that photoactivation of these neurons elicits 1) robust hyperglycemia achieved by activation of counterregulatory responses usually reserved for the physiological response to hypoglycemia and 2) defensive immobility behavior. Moreover, we show that the glucagon, but not corticosterone, response to insulin-induced hypoglycemia is blunted by photoinhibition of the same neurons. To investigate the neurocircuitry by which VMNNOS1 neurons mediate these effects, and to determine whether these diverse effects are dissociable from one another, we activated downstream VMNNOS1 projections in either the anterior bed nucleus of the stria terminalis (aBNST) or the periaqueductal gray (PAG). Whereas glycemic responses are fully recapitulated by activation of VMNNOS1 projections to the aBNST, freezing immobility occurred only upon activation of VMNNOS1 terminals in the PAG. These findings support previous evidence of a VMNâaBNST neurocircuit involved in glucose counterregulation and demonstrate that activation of VMNNOS1 neuronal projections supplying the PAG robustly elicits defensive behaviors.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Núcleos Septales
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Núcleo Hipotalámico Ventromedial
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Conducta Animal
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Sustancia Gris Periacueductal
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Óxido Nítrico Sintasa de Tipo I
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Glucosa
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Hipoglucemia
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Neuronas
Límite:
Animals
Idioma:
En
Revista:
Diabetes
Año:
2018
Tipo del documento:
Article