Hindbrain Catecholamine Neurons Activate Orexin Neurons During Systemic Glucoprivation in Male Rats

Hindbrain Catecholamine Neurons Activate Orexin Neurons During Systemic Glucoprivation in Male Rats

Hindbrain catecholamine neurons are required for elicitation of feeding responses to glucose deficit, but the forebrain circuitry required for these responses is incompletely understood. Here we examined interactions of catecholamine and orexin neurons in eliciting glucoprivic feeding. Orexin neuron...

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Bibliographic Details
Published in:Endocrinology (Philadelphia) Vol. 156; no. 8; pp. 2807 - 2820
Main Authors: Li, Ai-Jun, Wang, Qing, Elsarelli, Megan M, Brown, R. Lane, Ritter, Sue
Format: Journal Article
Language:English
Published: United States Endocrine Society 01-08-2015
Oxford University Press
Subjects:
Animals
Arousal
c-Fos protein
Catecholamine
Catecholamines
Catecholamines - metabolism
Circuits
Clozapine
Cre recombinase
Deoxyglucose - pharmacology
Dopamine
Dopamine transporter
Dopamine β-monooxygenase
Eating - drug effects
Eating - physiology
Feeding
Food
Food intake
Forebrain
Glucose
Glucose - antagonists & inhibitors
Glucose - deficiency
Hindbrain
Hypothalamus
Hypothalamus (lateral)
Immunotoxins
Injection
Innervation
Intracellular Signaling Peptides and Proteins - metabolism
Male
Medulla oblongata
Neurons
Neurons - drug effects
Neurons - metabolism
Neurons - physiology
Neuropeptides - metabolism
Orexins
Original Research
Raphe nuclei
Rats
Rats, Sprague-Dawley
Rats, Transgenic
Rhombencephalon - drug effects
Rhombencephalon - metabolism
Saporin
Tyrosine
Tyrosine 3-monooxygenase
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Description
Summary:Hindbrain catecholamine neurons are required for elicitation of feeding responses to glucose deficit, but the forebrain circuitry required for these responses is incompletely understood. Here we examined interactions of catecholamine and orexin neurons in eliciting glucoprivic feeding. Orexin neurons, located in the perifornical lateral hypothalamus (PeFLH), are heavily innervated by hindbrain catecholamine neurons, stimulate food intake, and increase arousal and behavioral activation. Orexin neurons may therefore contribute importantly to appetitive responses, such as food seeking, during glucoprivation. Retrograde tracing results showed that nearly all innervation of the PeFLH from the hindbrain originated from catecholamine neurons and some raphe nuclei. Results also suggested that many catecholamine neurons project collaterally to the PeFLH and paraventricular hypothalamic nucleus. Systemic administration of the antiglycolytic agent, 2-deoxy-D-glucose, increased food intake and c-Fos expression in orexin neurons. Both responses were eliminated by a lesion of catecholamine neurons innervating orexin neurons using the retrogradely transported immunotoxin, anti-dopamine-β-hydroxylase saporin, which is specifically internalized by dopamine-β-hydroxylase-expressing catecholamine neurons. Using designer receptors exclusively activated by designer drugs in transgenic rats expressing Cre recombinase under the control of tyrosine hydroxylase promoter, catecholamine neurons in cell groups A1 and C1 of the ventrolateral medulla were activated selectively by peripheral injection of clozapine-N-oxide. Clozapine-N-oxide injection increased food intake and c-Fos expression in PeFLH orexin neurons as well as in paraventricular hypothalamic nucleus neurons. In summary, catecholamine neurons are required for the activation of orexin neurons during glucoprivation. Activation of orexin neurons may contribute to appetitive responses required for glucoprivic feeding.
Bibliography:This work was supported by Public Health Service Grants DK 040498 and DK 081546.
ISSN:0013-7227
1945-7170
DOI:10.1210/en.2015-1138