An Intact Dorsomedial Hypothalamic Nucleus, but Not the Subzona Incerta or Reuniens Nucleus, Is Necessary for Short-Day Melatonin Signal-Induced Responses in Siberian Hamsters

Leitner, Claudia; Bartness, Timothy J.

doi:10.1159/000320474

Cited by 12 publications

(13 citation statements)

References 85 publications

(80 reference statements)

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“…The Re may also influence circadian and seasonal adaptations affecting body weight. In siberian hamsters, Re lesions may potentiate weight gain during long photoperiods and inhibit loss of body weight during short photoperiods (Purvis and Duncan, 1997), but this latter effect was not replicated in a more recent study (Leitner and Bartness, 2011). …”

Section: Evidence For the Role Of The Reuniens (Re) And Rhomboid (mentioning

confidence: 97%

The reuniens and rhomboid nuclei: Neuroanatomy, electrophysiological characteristics and behavioral implications

Cassel

Vasconcelos

Loureiro

et al. 2013

Progress in Neurobiology

168

135

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The reuniens and rhomboid nuclei, located in the ventral midline of the thalamus, have long been regarded as having non-specific effects on the cortex, while other evidence suggests that they influence behavior related to the photoperiod, hunger, stress or anxiety. We summarise the recent anatomical, electrophysiological and behavioral evidence that these nuclei also influence cognitive processes. The first part of this review describes the reciprocal connections of the reuniens and rhomboid nuclei with the medial prefrontal cortex and the hippocampus. The connectivity pattern among these structures is consistent with the idea that these ventral midline nuclei represent a nodal hub to influence prefrontalhippocampal interactions. The second part describes the effects of a stimulation or blockade of the ventral midline thalamus on cortical and hippocampal electrophysiological activity. The final part summarizes recent literature supporting the emerging view that the reuniens and rhomboid nuclei may contribute to learning, memory consolidation and behavioral flexibility, in addition to general behavior and aspects of metabolism.

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Section: Evidence For the Role Of The Reuniens (Re) And Rhomboid (mentioning

confidence: 97%

The reuniens and rhomboid nuclei: Neuroanatomy, electrophysiological characteristics and behavioral implications

Cassel

Vasconcelos

Loureiro

et al. 2013

Progress in Neurobiology

168

135

View full text Add to dashboard Cite

show abstract

“…After these tests of sufficiency, we conducted tests of necessity by making lesions of the areas and giving systemic timed melatonin treatments that mimicked endogenous SD-like melatonin durations. We found that only the SCN and the DMH were necessary for the increased lipid mobilization (decreased WAT mass; [17;183;270;271]).…”

Section: Sympathetic Drive To White Adipose Tissue Is Not Uniformmentioning

confidence: 99%

Neural innervation of white adipose tissue and the control of lipolysis

Bartness

Liu

Shrestha

et al. 2014

Frontiers in Neuroendocrinology

Self Cite

276

263

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White adipose tissue (WAT) is innervated by the sympathetic nervous system (SNS) and its activation is necessary for lipolysis. WAT parasympathetic innervation is not supported. Fully-executed SNS-norepinephrine (NE)-mediated WAT lipolysis is dependent on β-adrenoceptor stimulation ultimately hinging on hormone sensitive lipase and perilipin A phosphorylation. WAT sympathetic drive is appropriately measured by electrophysiological and neurochemical (NE turnover) in non-human animals and this drive is fat pad-specific preventing generalizations among WAT depots and non-WAT organs. Leptin-triggered SNS-mediated lipolysis is weakly supported, whereas insulin or adenosine inhibition of SNS/NE-mediated lipolysis is strongly supported. In addition to lipolysis control, increases or decreases in WAT SNS drive/NE inhibit and stimulate white adipocyte proliferation, respectively. WAT sensory nerves are of spinal-origin and sensitive to local leptin and increases in sympathetic drive, the latter implicating lipolysis. Transsynaptic viral tract tracer use revealed WAT central sympathetic and sensory circuits including SNS-sensory feedback loops that may control lipolysis.

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“…A distributed system of hypothalamic and thalamic sites mediates SD reproductive responses of Siberian hamsters to Mel [14,21,33]. Mel implants in multiple sites each induce testicular regression in LDs; the subsequent development of refractoriness to Mel also occurs independently at each site.…”

Section: Discussionmentioning

confidence: 99%

“…In both Siberian and Syrian hamsters, ablation of the DMN, or the DMN/ventromedial nucleus (VMN) complex of Syrian hamsters, blocks testicular responses to SDs [16,17,21,22], without compromising Mel signaling [16,17,23]. Ablation of the DMN does not mask reproductive responses to SDs by inducing hypersecretion of gonadotrophins [17].…”

Section: Introductionmentioning

confidence: 99%

Dorsomedial Hypothalamic Lesions Block Syrian Hamster Testicular Regression in Short Day Lengths Without Diminishing Increased Testosterone Negative-Feedback Sensitivity1

Jarjisian

Piekarski

Place

et al. 2013

Biology of Reproduction

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The dorsomedial nucleus (DMN) of the hypothalamus, the only site within the mediobasal hypothalamus of Syrian hamsters that both binds melatonin and has abundant concentrations of androgen receptors, has been proposed as a target tissue for induction of seasonal changes in brain sensitivity to steroid negative feedback. We tested whether DMN ablation, which does not interfere with pineal gland secretion of melatonin in short day lengths, prevents testicular regression by altering sensitivity to steroid negative feedback. Hamsters with DMN lesions, unlike control hamsters, failed to undergo testicular regression after transfer from a long (14 h light/day) to a short day length (8 h light/day); however, increased negative-feedback inhibition of follicle-stimulating hormone by testosterone was not compromised by ablation of the DMN, indicating that this tissue is not an essential mediator of seasonal changes in feedback sensitivity. We propose a redundant neural network comprised of multiple structures, each of which contributes to neuroendocrine mechanisms, that determines the effect of short days on gonadal function.

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An Intact Dorsomedial Hypothalamic Nucleus, but Not the Subzona Incerta or Reuniens Nucleus, Is Necessary for Short-Day Melatonin Signal-Induced Responses in Siberian Hamsters

Cited by 12 publications

References 85 publications

The reuniens and rhomboid nuclei: Neuroanatomy, electrophysiological characteristics and behavioral implications

The reuniens and rhomboid nuclei: Neuroanatomy, electrophysiological characteristics and behavioral implications

Neural innervation of white adipose tissue and the control of lipolysis

Dorsomedial Hypothalamic Lesions Block Syrian Hamster Testicular Regression in Short Day Lengths Without Diminishing Increased Testosterone Negative-Feedback Sensitivity1

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