Neuron–Glia Interaction in the Suprachiasmatic Nucleus: A Double Labeling Light and Electron Microscopic Immunocytochemical Study in the Rat

Tamada, Yoshitaka; Tanaka, Masaki; Munekawa, Katsuhiko; Hayashi, Seiji; Okamura, Hitoshi; Kubo, Toshikazu; Hisa, Yasuo; Ibata, Yasuhiko

doi:10.1016/s0361-9230(97)00403-6

Cited by 32 publications

(25 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In support to this view, it has been shown that glucocorticoids influence the diurnal expression of the two main peptides synthesized in the SCN, vasopressin and vasoactive intestinal peptide (VIP) (Larsen et al, 1994), and there are ultrastructural data to suggest that these diurnal changes may be facilitated by astroglial elements (Tamada et al, 1998). The present study was a preliminary step toward characterizing the effects of the circadian fluctuations of glucocorticoids on neuronal-glial plasticity in the rat SCN.…”

Section: Introductionmentioning

confidence: 62%

Glucocorticoids up-regulate the expression of glial fibrillary acidic protein in the rat suprachiasmatic nucleus

Maurel

Sage

Mekaouche

et al. 2000

Glia

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 62%

Glucocorticoids up-regulate the expression of glial fibrillary acidic protein in the rat suprachiasmatic nucleus

Maurel

Sage

Mekaouche

et al. 2000

Glia

View full text Add to dashboard Cite

“…Therefore, there must be additional, nonsynaptic interactions between the AMe neurons such as gap junctions, glia-neuron interactions, or nonsynaptic release of neuromediators (Shinohara et al, 1995;Jiang et al, 1997;Tamada et al, 1998;Michel and Colwell, 2001;Cheng et al, 2002;Schaap et al, 2003). We are currently testing with dye injections as well as pharmacologically whether gap junctions couple AMe neurons.…”

Section: Discussionmentioning

confidence: 99%

Pigment-Dispersing Factor and GABA Synchronize Cells of the Isolated Circadian Clock of the CockroachLeucophaea maderae

Schneider¹,

Stengl²

2005

J. Neurosci.

View full text Add to dashboard Cite

Pigment-dispersing factor-immunoreactive circadian pacemaker cells, which arborize in the accessory medulla, control circadian locomotor activity rhythms in Drosophila as well as in the cockroach Leucophaea maderae via unknown mechanisms. Here, we show that circadian pacemaker candidates of the accessory medulla of the cockroach produce regular interspike intervals. Therefore, the membrane potential of the cells oscillates with ultradian periods. Most or all oscillating cells within the accessory medulla are coupled via synaptic and nonsynaptic mechanisms, forming different assemblies. The cells within an assembly share the same ultradian period (interspike interval) and the same phase (timing of spikes), whereas cells between assemblies differ in phase. Apparently, the majority of these assemblies are formed by inhibitory GABAergic synaptic interactions. Application of pigment-dispersing factor phase locked and thereby synchronized different assemblies. The data suggest that pigment-dispersing factor inhibits GABAergic interneurons, resulting in disinhibition and phase locking of their postsynaptic cells, which previously belonged to different assemblies. Our data suggest that phase control of action potential oscillations in the ultradian range is a main task of the circadian pacemaker network. We hypothesize that neuropeptide-dependent phase control is used to gate circadian outputs to locomotor control centers.

show abstract

“…However, there are references to unpublished data in several other publications indicating the absence of circadian GFAP rhythm. For instance, Tamada et al (1998) studied the morphological interactions between neural and astroglial elements in the rat SCN. In that study, although all of the animals had been sacrificed at the same time, ZT 07, the authors comment they did not observe any significant rhythmicity of GFAP-Ir in the rat SCN based in unpublished data.…”

Section: Discussionmentioning

confidence: 99%

“…In a recent study, Ikeda et al (2003) have described a significant decrease of GFAP-Ir in the SCN of rats kept in DD since birth compared with the controls raised in LD. In that paper, the authors discuss the absence of circadian variation of GFAP-Ir in the rat SCN, referring to the Tamada et al (1998) study mentioned above. According to these findings, it appears that the question of the circadian variation of the GFAP-Ir in the rat SCN is not yet answered.…”

Section: Discussionmentioning

confidence: 99%

Circadian variation in GFAP immunoreactivity in the mouse suprachiasmatic nucleus

Santos¹,

Araújo²,

Cunha³

et al. 2005

Biological Rhythm Research

View full text Add to dashboard Cite

One of the most important functions of biological rhythms is to assure that behavioral and physiological functions are timed optimally in with respect to each other and to the environmental cycles. In mammals, this temporal regulation is driven by a circadian timing system which comprises a circadian pacemaker located in the retinorecipient hypothalamic suprachiasmatic nucleus (SCN), along with a complex network of efferent pathways and target tissues. In this study we investigated the existence of circadian variation in the immunohistochemical expression of glial fibrillary acidic protein (GFAP) in the mouse SCN. We used both entrainment and free-running conditions, and examined GFAP expression at different time points according to 24 hour Zeitgeber time (ZT) and circadian time (CT), respectively. Animals were perfused transcardially, and fixed brain sections containing the SCN were processed for GFAP immunoreactivity. GFAP-Ir was quantified by the percentage measure of pixels method for post-hoc statistical analysis of data. The results indicate the existence of a circadian variation on the expression of the GFAP immunoreactivity in the SCN of the animals of both experimental groups furnishing a contribution to the polemic question that has been raised. Further studies, directed especially to the development of new methods for the measurement of the immunoreactivity of this protein, are essential.

show abstract

Neuron–Glia Interaction in the Suprachiasmatic Nucleus: A Double Labeling Light and Electron Microscopic Immunocytochemical Study in the Rat

Cited by 32 publications

References 31 publications

Glucocorticoids up-regulate the expression of glial fibrillary acidic protein in the rat suprachiasmatic nucleus

Glucocorticoids up-regulate the expression of glial fibrillary acidic protein in the rat suprachiasmatic nucleus

Pigment-Dispersing Factor and GABA Synchronize Cells of the Isolated Circadian Clock of the CockroachLeucophaea maderae

Circadian variation in GFAP immunoreactivity in the mouse suprachiasmatic nucleus

Contact Info

Product

Resources

About