Suprachiasmatic nucleus neurons immunoreactive for vasoactive intestinal polypeptide have synaptic contacts with axons immunoreactive for neuropeptide Y: An immunoelectron microscopic study in the rat

Hisano, Setsuji; Chikamori-Aoyama, Mika; Katoh, Shinsuke; Kagotani, Yasuaki; Daikoku, Shigeo; Chihara, Kazuo

doi:10.1016/0304-3940(88)90116-4

Cited by 99 publications

(23 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The latter region, by its projections to the SCN, viz. the geniculohypothalamic tract (GHT), provides a secondary indirect visual input to the nucleus via NPY fibres synapsing on VIP neurons (Hisano et al 1988). It is assumed that this projection plays an important role in the generation and maintenance of the circadian rhythm (Johnson et al 1989).…”

Section: Afferents To the Scnmentioning

confidence: 98%

Components and connections of the circadian timing system in mammals

Reuss

1996

Cell and Tissue Research

103

View full text Add to dashboard Cite

The circadian timing system is a neural network consisting of the hypothalamic suprachiasmatic nucleus, aided by the retina, other hypothalamic nuclei, autonomic regions of the spinal cord, sympathetic ganglia and the pineal gland. Extensive studies conducted over the last two decades have unravelled the principal items of its functional neuroanatomy. The system is responsible for the generation of the circadian rhythm, its synchronization by environmental factors such as light, and its mediation with respect to morphological, physiological and biochemical parameters of mammals that exhibit distinct alterations throughout the 24-h cycle. This review characterizes the brain sites involved and the pathways responsible for the generation and maintenance of circadian rhythmicity.

show abstract

Section: Afferents To the Scnmentioning

confidence: 98%

Components and connections of the circadian timing system in mammals

Reuss

1996

Cell and Tissue Research

103

View full text Add to dashboard Cite

show abstract

“…In Phodo pus, as in other mammals studied, the IGL exhibited strong NPY-like immunoreactivity of perikarya and fi bers. Fibers of the geniculohypothalamic tract contact vasoactive intestinal polvpeptide-like immunoreactive neurons by synapses of mainly inhibitory nature [19,20], It seems to be of major importance for the regulation of circadian rhythms since phase shifting is altered by IGL lesions [21] or is induced by NPY injection into the SCN [9].…”

Section: Discussionmentioning

confidence: 99%

Neuropeptide Y: Distribution of Immunoreactivity and Quantitative Analysis in Diencephalic Structures and Cerebral Cortex of Dwarf Hamsters under Different Photoperiods

Reuss

Olcese²

1995

Neuroendocrinology

View full text Add to dashboard Cite

The distribution of neuropeptide Y-like immunoreactivity (NPY-LI) was investigated by immunohistochemistry and radioimmunoassay (RIA) in the brain of the Djungarian hamster (Phodopus sungorus) held under either long or short photoperiods. In the diencephalic and telencephalic structures studied, distinct patterns of NPY-LI were basically consistent in male and female animals of both groups. NPY levels detected by RIA from tissue samples taken at six time points throughout the 24-hour cycle were in the range of 15-60 pmol/ mg protein in the diencephalon or below 5 pmol/mg protein in cerebral cortex. In the diencephalon, immunoreactive structures were seen in the preoptic, peri- and paraventricular, supraoptic, anterior, lateral, dorso- and ventromedial hypothalamic nuclei and in the median eminence. The suprachiasmatic nuclei exhibited a dense innervation by NPY-LI terminals mainly in its ventrolateral subdivision. NPY levels in the suprachiasmatic nucleus were nocturnal-ly augmented under long-day, but not under short-day conditions. The quantification of NPY in the paraventricular nucleus revealed a decrease at night in long-day animals and a small nocturnal augmentation in short-day hamsters. In the pineal gland and habenular nuclei, varicose fibers were observed which appeared mainly perivascular in location (pineal) or formed a dense plexus (habenular nuclei). Pineal NPY contents fell during the night in long-day animals and were relatively constant in short-day hamsters. NPY-LI structures were also observed in the metathalamic intergeniculate leaflet and in a variety of telencephalic structures including the cerebral cortex, caudate nucleus puta-men, lateral septal nucleus, bed nucleus of the stria terminalis and amygdala.

show abstract

“…Photic information conveyed by these pathways entrains the circadian clock to an environmental light /dark time schedule (Meijer and Rietveld, 1989). VIP neurons in the VLSCN receive synaptic contacts by both the direct and indirect (Hisano et al, 1988) pathways, and it is known that VIP gene expression is negatively regulated by the photic stimuli Albers et al, 1990;Okamoto et al, 1991). Because the light-evoked rhythms disappear under constant dark (DD) conditions and the VIP level decreased in proportion to the duration of light exposure (Shinohara et al, 1993), the expression of VIP is driven not by an endogenous circadian clock, but rather by the photic information, when the adult SCN was examined.…”

mentioning

confidence: 99%

Development of Vasoactive Intestinal Peptide mRNA Rhythm in the Rat Suprachiasmatic Nucleus

1997

View full text Add to dashboard Cite

Development of the daily rhythm of vasoactive intestinal peptide (VIP) mRNA in the rat suprachiasmatic nucleus (SCN), a main locus of circadian oscillation, was investigated by in situ hybridization. The phenotypic expression of VIP neurons occurred in two developmental stages in the ventrolateral portion of the SCN (VLSCN): the first was found before birth in the rostral part, and the second occurred in the main part between postnatal day (P) 10 and P20. The latter period coincided with the time that the massive VIP-efferent fibers project to the subparaventricular zone. In the adult and P20, the VIP mRNA signals of the SCN showed a clear diurnal rhythm with a trough in the light phase and a peak in the dark phase under light/dark (LD) conditions, but under constant dark (DD) conditions, no VIP mRNA fluctuations were observed. At P10, however, it was found that SCN VIP mRNA showed a peak at the transition from night to day and a trough at early dark period in LD conditions, in sharp contrast to the night peak in the adult rhythm. In DD conditions, a light-phase peak and a dark-phase trough were also observed at P10, contrasting the arrhythmic feature at adult stage. The present findings suggest that daily VIP rhythm was first generated in the early developed clock-controlled rostral SCN neurons, and later regulated by light-dependent main VLSCN neurons.

show abstract

Suprachiasmatic nucleus neurons immunoreactive for vasoactive intestinal polypeptide have synaptic contacts with axons immunoreactive for neuropeptide Y: An immunoelectron microscopic study in the rat

Cited by 99 publications

References 11 publications

Components and connections of the circadian timing system in mammals

Components and connections of the circadian timing system in mammals

Neuropeptide Y: Distribution of Immunoreactivity and Quantitative Analysis in Diencephalic Structures and Cerebral Cortex of Dwarf Hamsters under Different Photoperiods

Development of Vasoactive Intestinal Peptide mRNA Rhythm in the Rat Suprachiasmatic Nucleus

Contact Info

Product

Resources

About