Changes in the suprachiasmatic nucleus during aging: Implications for biological rhythms.

Engelberth, Rovena Clara Galvão Januário; Pontes, André Luiz Bezerra de; Fiuza, Felipe Porto; Silva, Kayo D. de Azevedo; Resende, Nayra da Silva; Azevedo, Carolina Virgínia de M.; Costa, Miriam S.M.O.; Cavalcante, Judney Cley; Nascimento, Expedito Silva do; Gavioli, Elaine C.

doi:10.3922/j.psns.2013.3.07

Cited by 12 publications

(6 citation statements)

References 135 publications

(193 reference statements)

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“…Aging is associated with changes in homeostatic function, such as disrupted hormone rhythms and wake-sleep cycles (Duffy et al 2002, Yoon et al 2003; Downs & Urbanski 2006; Downs et al 2007; Urbanski 2011). Perturbed circadian rhythms have been associated with disease, behavioral and cognitive deficits, as well as increased mortality (Davidson et al 2006; Urbanski et al 2011; Engelberth et al, 2013). Although the SCN plays a primary role in maintaining circadian rhythms, the SCN of primates has not been characterized extensively (Moore 1993).…”

Section: Discussionmentioning

confidence: 99%

Gene expression profiling of the SCN in young and old rhesus macaques

Eghlidi

Luna

Brown

et al. 2018

Journal of Molecular Endocrinology

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In mammals, the suprachiasmatic nucleus (SCN) is the location of a master circadian pacemaker. It receives photic signals from the environment via the retinal hypothalamic tract, which play a key role in synchronizing the body's endogenously generated circadian rhythms with the 24-h rhythm of the environment. Therefore, it is plausible that age-related changes within the SCN contribute to the etiology of perturbed activity-rest cycles that become prevalent in humans during aging. To test this hypothesis, we used gene arrays and quantitative RT-PCR to profile age-related gene expression changes within the SCN of male rhesus macaques - a pragmatic translational animal model of human aging, which similarly displays an age-related attenuation of daytime activity levels. As expected, the SCN showed high expression of arginine vasopressin, vasoactive intestinal polypeptide, calbindin and nuclear receptor subfamily 1, group D, member 1 (NR1D1) (also known as reverse strand of ERBA (REV-ERBα), both at the mRNA and protein level. However, no obvious difference was detected between the SCNs of young (7-12 years) and old animals (21-26 years), in terms of the expression of core clock genes or genes associated with SCN signaling and neurotransmission. These data demonstrate the resilience of the primate SCN to normal aging, at least at the transcriptional level and, at least in males, suggest that age-related disruption of activity-rest cycles in humans may instead stem from changes within other components of the circadian system, such as desynchronization of subordinate oscillators in other parts of the body.

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Section: Discussionmentioning

confidence: 99%

Gene expression profiling of the SCN in young and old rhesus macaques

Eghlidi

Luna

Brown

et al. 2018

Journal of Molecular Endocrinology

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“…Aging affects the overall physiology, including visual, and circadian functions (Kondratova and Kondratov, 2012 ; Engelberth et al, 2013 ; Yan et al, 2020 ). After light reaches the retina, visual pathways to the brain nuclei are commonly grouped into image-forming and non-image forming visual systems (Lucas et al, 2014 ; Sondereker et al, 2020 ).…”

Section: Introductionmentioning

confidence: 99%

Aging Alters Daily and Regional Calretinin Neuronal Expression in the Rat Non-image Forming Visual Thalamus

Fiuza¹,

Queiroz²,

Aquino

et al. 2021

Front. Aging Neurosci.

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Aging affects the overall physiology, including the image-forming and non-image forming visual systems. Among the components of the latter, the thalamic retinorecipient inter-geniculate leaflet (IGL) and ventral lateral geniculate (vLGN) nucleus conveys light information to subcortical regions, adjusting visuomotor, and circadian functions. It is noteworthy that several visual related cells, such as neuronal subpopulations in the IGL and vLGN are neurochemically characterized by the presence of calcium binding proteins. Calretinin (CR), a representative of such proteins, denotes region-specificity in a temporal manner by variable day–night expression. In parallel, age-related brain dysfunction and neurodegeneration are associated with abnormal intracellular concentrations of calcium. Here, we investigated whether daily changes in the number of CR neurons are a feature of the aged IGL and vLGN in rats. To this end, we perfused rats, ranging from 3 to 24 months of age, within distinct phases of the day, namely zeitgeber times (ZTs). Then, we evaluated CR immunolabeling through design-based stereological cell estimation. We observed distinct daily rhythms of CR expression in the IGL and in both the retinorecipient (vLGNe) and non-retinorecipient (vLGNi) portions of the vLGN. In the ZT 6, the middle of the light phase, the CR cells are reduced with aging in the IGL and vLGNe. In the ZT 12, the transition between light to dark, an age-related CR loss was found in all nuclei. While CR expression predominates in specific spatial domains of vLGN, age-related changes appear not to be restricted at particular portions. No alterations were found in the dark/light transition or in the middle of the dark phase, ZTs 0, and 18, respectively. These results are relevant in the understanding of how aging shifts the phenotype of visual related cells at topographically organized channels of visuomotor and circadian processing.

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“…Changes in aged circadian clock are described in many levels (see Engelberth et al 2013). For instance, the aging process is associated with declines in biological rhythm amplitude and phase duration controlled by the clock (Satinoff et al 1993) as well as fragmentation of locomotor activity rhythm (Valentinuzzi et al 1997).…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, SCN have a reduced expression of two major neurochemical constituents, vasoactive intestinal polypeptide (Chee et al 1988;Krajnak et al 1998), and vasopressin (Roozendaal et al 1987;Cayetanot et al 2005), which accounts to a weakening of SCN interconnections, therefore affecting the circadian clock functionality (Engelberth et al 2013). Current data, however, are focused solely on the aging effects on SCN, which brings a limitation to understand the whole process of aging in CTS (Yamazaki et al 2002;Davidson et al 2008).…”

Section: Introductionmentioning

confidence: 99%

Age-related changes in neurochemical components and retinal projections of rat intergeniculate leaflet

Fiuza

Silva

Pessoa

et al. 2015

AGE

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Aging leads to several anatomical and functional deficits in circadian timing system. In previous works, we observed morphological alterations with age in hypothalamic suprachiasmatic nuclei, one central component of this system. However, there are few data regarding aging effects on other central components of this system, such as thalamic intergeniculate leaflet (IGL). In this context, we studied possible age-related alterations in neurochemical components and retinal projections of rat IGL. For this goal, young (3 months), adult (13 months), and aged (23 months) Wistar rats were submitted to an intraocular injection of neural tracer, cholera toxin subunit b (CTb), 5 days before a tissue fixation process by paraformaldehyde perfusion. Optical density measurements and cell count were performed at digital pictures of brain tissue slices processed by immunostaining for glutamic acid decarboxylase (GAD), enkephalin (ENK), neuropeptide Y (NPY) and CTb, characteristic markers of IGL and its retinal terminals. We found a significant age-related loss in NPY immunoreactive neurons, but not in immunoreactivity to GAD and ENK. We also found a decline of retinal projections to IGL with age. We conclude aging impairs both a photic environmental clue afferent to IGL and a neurochemical expression which has an important modulatory circadian function, providing strong anatomical correlates to functional deficits of the aged biological clock.

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Changes in the suprachiasmatic nucleus during aging: Implications for biological rhythms.

Cited by 12 publications

References 135 publications

Gene expression profiling of the SCN in young and old rhesus macaques

Gene expression profiling of the SCN in young and old rhesus macaques

Aging Alters Daily and Regional Calretinin Neuronal Expression in the Rat Non-image Forming Visual Thalamus

Age-related changes in neurochemical components and retinal projections of rat intergeniculate leaflet

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