Immunocytochemical evidence for different patterns in daily rhythms of VIP and AVP peptides in the suprachiasmatic nucleus of diurnal Funambulus palmarum

Mammen, Anumodh Pazhoor; Jagota, Anita

doi:10.1016/j.brainres.2010.12.018

Cited by 9 publications

(4 citation statements)

References 64 publications

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“…This feature has already been described in diurnal rodents (Chakir et al, 2015), while CLOCK expression in the SCN is more generally constitutive in the SCN of nocturnal animals (Mendoza et al, 2007). Here we also noticed that the optic nerve and optic chiasm are much thicker when compared to those of nocturnal rodents, in line with previous observations done in another diurnal species, the Indian palm squirrel (Mammen and Jagota, 2011). Unexpectedly, our actimetry data reveal that most Psammomys have a nocturnal pattern of activity, while few individuals were even arrhythmic.…”

Section: Scn Organization Neuropeptides and Clock Cycling In Psammomyssupporting

confidence: 92%

Diet-induced insulin resistance state disturbs brain clock processes and alters tuning of clock outputs in the Sand rat, Psammomys obesus

et al. 2018

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Reciprocal interactions closely connect energy metabolism with circadian rhythmicity. Altered clockwork and circadian desynchronization are often linked with impaired energy regulation. Conversely, metabolic disturbances have been associated with altered autonomic and hormonal rhythms. The effects of high-energy (HE) diet on the master clock in the suprachiasmatic nuclei (SCN) remain unclear.This question was addressed in the Sand rat (Psammomys obesus), a non-insulin-dependent diabetes mellitus (NIDDM) animal model. The aim of this work was to determine whether enriched diet in Psammomys affects locomotor activity rhythm, as well as daily oscillations in the master clock of the SCN and in an extra-SCN brain oscillator, the piriform cortex. Sand rats were fed during 3 months with either low or HE diet. Vasoactive intestinal peptide (VIP), vasopressin (AVP) and CLOCK protein cycling were studied by immunohistochemistry and running wheel protocol was used for behavioral analysis. High energy feeding dietary triggered hyperinsulinemia, impaired insulin/glucose ratio and disruption in pancreatic hormonal rhythms. Circadian disturbances in hyper-insulinemic animals include a lengthened rest/activity rhythm in constant darkness, as well as disappearance of daily rhythmicity of VIP, AVP and the circadian transcription factor CLOCK within the suprachiasmatic clock. In addition, daily rhythmicity of VIP and CLOCK was abolished by HE diet in a secondary brain oscillator, the piriform cortex. Our findings highlight a major impact of diabetogenic diet on central and peripheral rhythmicity. The Psammomys model will be instrumental to better understand the functional links between circadian clocks, glucose intolerance and insulin resistance state.

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Section: Scn Organization Neuropeptides and Clock Cycling In Psammomyssupporting

confidence: 92%

Diet-induced insulin resistance state disturbs brain clock processes and alters tuning of clock outputs in the Sand rat, Psammomys obesus

et al. 2018

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“…In contrast, in the SCN of diurnal grass rats, these rhythms do not become stronger; rather, they show a shift in their peak time of expression ( 297 ). Moreover, in the SCN of three-striped South Indian squirrels ( Funambulus palmarum , a diurnal species), the phase relation of daily VIP and AVP rhythms differ from those found in nocturnal species ( 298 ). Recently, a study of the SCN in capuchin monkeys confirmed the presence of circadian oscillations in PER2 in the SCN of primates ( 299 ).…”

Section: Comparison Of the Scn Between Nocturnal And Diurnal Animalsmentioning

confidence: 97%

Synchronization of Biological Clock Neurons by Light and Peripheral Feedback Systems Promotes Circadian Rhythms and Health

2015

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In mammals, the suprachiasmatic nucleus (SCN) functions as a circadian clock that drives 24-h rhythms in both physiology and behavior. The SCN is a multicellular oscillator in which individual neurons function as cell-autonomous oscillators. The production of a coherent output rhythm is dependent upon mutual synchronization among single cells and requires both synaptic communication and gap junctions. Changes in phase-synchronization between individual cells have consequences on the amplitude of the SCN’s electrical activity rhythm, and these changes play a major role in the ability to adapt to seasonal changes. Both aging and sleep deprivation negatively affect the circadian amplitude of the SCN, whereas behavioral activity (i.e., exercise) has a positive effect on amplitude. Given that the amplitude of the SCN’s electrical activity rhythm is essential for achieving robust rhythmicity in physiology and behavior, the mechanisms that underlie neuronal synchronization warrant further study. A growing body of evidence suggests that the functional integrity of the SCN contributes to health, well-being, cognitive performance, and alertness; in contrast, deterioration of the 24-h rhythm is a risk factor for neurodegenerative disease, cancer, depression, and sleep disorders.

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“…As the primary oscillator of the CTS, the SCN ( Figure 2 ) of the anterior hypothalamus conveys temporal information, synchronizing the other clocks in the brain and body to produce coherent circadian rhythms at physiological and behavioral levels ( Astiz et al, 2019 ). Immediately dorsal to the optic chiasm, and flanking the third ventricle ( Moore and Lenn, 1972 ; Van den Pol, 1991 ), the SCN is conventionally divided into two functionally distinct domains, a ventrolateral/core and dorsomedial/shell subnuclei, distinguished by neuronal cytoarchitecture ( Van den Pol, 1980 ; Mammen and Jagota, 2011 ), neurochemical phenotype ( Moore et al, 2002 ; Morin, 2013 ; Allali et al, 2017 ), organization of afferent innervation ( Moga and Moore, 1997 ), distribution of efferent projections ( Leak and Moore, 2001 ), pattern of gene expression ( Dardente et al, 2002 ), and electrical activity ( Schaap et al, 2003 ). The functional significance of SCN compartments remains to be explored in detail, however, it is hypothesized that the prominent role of the core subregion is to maintain cellular coupling within the SCN and integrate relevant afferents for the entrainment of the master clock, while its shell subregion may have primary responsibility for coordinating the phase configuration of oscillators present in peripheral tissues and brain regions other than the SCN ( Dibner et al, 2010 ; Welsh et al, 2010 ; Evans et al, 2015 ).…”

Section: Non-image Forming Systemmentioning

confidence: 99%

Retinorecipient areas in the common marmoset (Callithrix jacchus): An image-forming and non-image forming circuitry

Santana

Silva

Santos

et al. 2023

Front. Neural Circuits

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The mammalian retina captures a multitude of diverse features from the external environment and conveys them via the optic nerve to a myriad of retinorecipient nuclei. Understanding how retinal signals act in distinct brain functions is one of the most central and established goals of neuroscience. Using the common marmoset (Callithrix jacchus), a monkey from Northeastern Brazil, as an animal model for parsing how retinal innervation works in the brain, started decades ago due to their marmoset’s small bodies, rapid reproduction rate, and brain features. In the course of that research, a large amount of new and sophisticated neuroanatomical techniques was developed and employed to explain retinal connectivity. As a consequence, image and non-image-forming regions, functions, and pathways, as well as retinal cell types were described. Image-forming circuits give rise directly to vision, while the non-image-forming territories support circadian physiological processes, although part of their functional significance is uncertain. Here, we reviewed the current state of knowledge concerning retinal circuitry in marmosets from neuroanatomical investigations. We have also highlighted the aspects of marmoset retinal circuitry that remain obscure, in addition, to identify what further research is needed to better understand the connections and functions of retinorecipient structures.

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Immunocytochemical evidence for different patterns in daily rhythms of VIP and AVP peptides in the suprachiasmatic nucleus of diurnal Funambulus palmarum

Cited by 9 publications

References 64 publications

Diet-induced insulin resistance state disturbs brain clock processes and alters tuning of clock outputs in the Sand rat, Psammomys obesus

Diet-induced insulin resistance state disturbs brain clock processes and alters tuning of clock outputs in the Sand rat, Psammomys obesus

Synchronization of Biological Clock Neurons by Light and Peripheral Feedback Systems Promotes Circadian Rhythms and Health

Retinorecipient areas in the common marmoset (Callithrix jacchus): An image-forming and non-image forming circuitry

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