Possible roles of photoperiod and melatonin in reproductive activity via changes in dopaminergic activity in the brain of a tropical damselfish, Chrysiptera cyanea

2013 ◽  
Vol 194 ◽  
pp. 240-247 ◽  
Author(s):  
Muhammad Badruzzaman ◽  
Mohammad Abu Jafor Bapary ◽  
Akihiro Takemura
Keyword(s):  
Reproductive Activity ◽  
Dopaminergic Activity ◽  
The Brain

scholarly journals A Role for Xanthurenic Acid in the Control of Brain Dopaminergic Activity

2021 ◽  
Vol 22 (13) ◽  
pp. 6974
Author(s):  
Omar Taleb ◽  
Mohammed Maammar ◽  
Christian Klein ◽  
Michel Maitre ◽  
Ayikoe Guy Mensah-Nyagan
Keyword(s):  
Dopamine Release ◽  
Intraperitoneal Administration ◽  
Glutamate Transporter ◽  
Fold Increase ◽  
Xanthurenic Acid ◽  
Metabotropic Receptors ◽  
Parent Molecule ◽  
Dopaminergic Activity ◽  
The Brain

Xanthurenic acid (XA) is a metabolite of the kynurenine pathway (KP) synthetized in the brain from dietary or microbial tryptophan that crosses the blood-brain barrier through carrier-mediated transport. XA and kynurenic acid (KYNA) are two structurally related compounds of KP occurring at micromolar concentrations in the CNS and suspected to modulate some pathophysiological mechanisms of neuropsychiatric and/or neurodegenerative diseases. Particularly, various data including XA cerebral distribution (from 1 µM in olfactory bulbs and cerebellum to 0.1–0.4 µM in A9 and A10), its release, and interactions with G protein-dependent XA-receptor, glutamate transporter and metabotropic receptors, strongly support a signaling and/or neuromodulatory role for XA. However, while the parent molecule KYNA is considered as potentially involved in neuropsychiatric disorders because of its inhibitory action on dopamine release in the striatum, the effect of XA on brain dopaminergic activity remains unknown. Here, we demonstrate that acute local/microdialysis-infusions of XA dose-dependently stimulate dopamine release in the rat prefrontal cortex (four-fold increase in the presence of 20 µM XA). This stimulatory effect is blocked by XA-receptor antagonist NCS-486. Interestingly, our results show that the peripheral/intraperitoneal administration of XA, which has been proven to enhance intra-cerebral XA concentrations (about 200% increase after 50 mg/kg XA i.p), also induces a dose-dependent increase of dopamine release in the cortex and striatum. Furthermore, our in vivo electrophysiological studies reveal that the repeated/daily administrations of XA reduce by 43% the number of spontaneously firing dopaminergic neurons in the ventral tegmental area. In the substantia nigra, XA treatment does not change the number of firing neurons. Altogether, our results suggest that XA may contribute together with KYNA to generate a KYNA/XA ratio that may crucially determine the brain normal dopaminergic activity. Imbalance of this ratio may result in dopaminergic dysfunctions related to several brain disorders, including psychotic diseases and drug dependence.

scholarly journals Individual differences in the effects of cannabinoids on motor activity, dopaminergic activity and DARPP-32 phosphorylation in distinct regions of the brain

2009 ◽  
Vol 13 (09) ◽  
pp. 1175-1191 ◽  
Author(s):  
Alexia Polissidis ◽  
Olga Chouliara ◽  
Andreas Galanopoulos ◽  
Georgia Rentesi ◽  
Maria Dosi ◽  
...  
Keyword(s):  
Individual Differences ◽  
Motor Activity ◽  
Dopaminergic Activity ◽  
The Brain

scholarly journals The Rhythmic Secretion of Mating-Induced Prolactin Secretion Is Controlled by Prolactin Acting Centrally

Endocrinology ◽  
2009 ◽  
Vol 150 (7) ◽  
pp. 3245-3251 ◽  
Author(s):  
Cleyde V. Helena ◽  
De'Nise T. McKee ◽  
Richard Bertram ◽  
Ameae M. Walker ◽  
Marc E. Freeman
Keyword(s):  
Dopaminergic Neurons ◽  
Immediate Release ◽  
Prolactin Secretion ◽  
Daily Rhythm ◽  
Dopaminergic Activity ◽  
Ovx Rats ◽  
Initial Release ◽  
Cervical Stimulation ◽  
The Brain

Artificial copulomimetic cervical stimulation (CS) induces an immediate release of oxytocin (OT) and prolactin (PRL) followed by a daily PRL rhythm characterized by nocturnal and diurnal surges. Although we have shown that the initial release of PRL is induced by the immediate release of OT, we tested whether the PRL that is released in response to CS is responsible for the initiation and maintenance of the subsequent PRL surges. Thus, we injected OVX rats centrally or peripherally with ovine PRL (oPRL) at 2200 h. Central oPRL induced PRL surges in OVX rats that were similar in size and timing to those of CS rats, whereas peripheral oPRL induced surges that were of smaller amplitude and delayed. We then infused a PRL antagonist (S179D, 0.1 ng/h) centrally into OVX and OVX-CS rats and measured the release of endogenous PRL and the activity of neuroendocrine dopaminergic neurons. Central infusion of S179D did not influence basal PRL secretion in OVX rats but prevented the expression of the CS-induced PRL surges and the accompanying noontime increase of CS-induced dopaminergic activity when continued for 3 d. However, central infusion of S179D only on the day of CS did not prevent the daily rhythm of PRL surges. These results demonstrate that PRL acts centrally to induce the PRL rhythm and that PRL in the brain is essential for the maintenance but not for the initiation of the CS-induced rhythmic PRL surges.

Nutritional status affects the microRNA profile of the hypothalamus of female sheep

2018 ◽  
Vol 30 (7) ◽  
pp. 946 ◽  
Author(s):  
Heng Yang ◽  
Shan Lin ◽  
Xiaoping Lei ◽  
Cong Yuan ◽  
Yaosheng Yu ◽  
...  
Keyword(s):  
Nutritional Status ◽  
Molecular Mechanisms ◽  
Reproductive Activity ◽  
Illumina Hiseq ◽  
Illumina Hiseq Sequencing ◽  
Photoperiodic Regulation ◽  
Micro Rnas ◽  
Microrna Profile ◽  
Polymerase Chain ◽  
The Brain

Recent studies on the seasonal regulation of the oestrous cycle in sheep have focussed mainly on the responses to photoperiod. However, the brain systems that control reproductive activity also respond to nutritional inputs, although the molecular mechanisms involved are not completely understood. One possibility is that small, non-coding RNAs, such as micro-RNAs (miRNAs), have significant influence. In the present study, the amounts and characteristics of miRNAs in hypothalamus from oestrous and anestrous ewes, fed low- or high-nutrient diets, were compared using Illumina HiSeq sequencing technology. In total, 398 miRNAs, including 261 novel miRNAs, were identified in ewes with an enhanced nutritional status (HEN), whereas 384 miRNAs, including 247 novel miRNAs, were identified in the ewes with a lesser nutritional status (HAN). There were eight conserved and 140 novel miRNAs expressed differentially between the two libraries. Based on quantitative real-time polymerase chain reaction, six miRNAs were assessed to verify the accuracy of the library database. Moreover, the correlation between the miRNA target and several upstream and downstream genes in the oestrus-related pathways were also verified in hypothalamus nerve cells. According to the results, nutritional status plays an important role in oestrous regulation in sheep, and the hypothalamic processes and pathways induced by nutritional signals (folic acid and tyrosine) are different from those induced by photoperiodic regulation of oestrus. We have expanded the repertoire of sheep miRNAs that could contribute to the molecular mechanisms that regulate the initiation of oestrous cycles in anestrous ewes in response to the influence of nutritional status.

The role of serotonin in Parkinsons' Disease: An integrated approach for research of motor, cognitive and affective symptoms with functional intervention studies

1998 ◽  
Vol 10 (4) ◽  
pp. 84-86
Author(s):  
A.F.G. Leentjens ◽  
F.R.J. Verhey ◽  
F.W. Vreeling ◽  
H.M. van Praag
Keyword(s):  
Intervention Studies ◽  
Integrated Approach ◽  
Parkinsons Disease ◽  
Dopaminergic Activity ◽  
Serotonergic Activity ◽  
Affective Symptoms ◽  
Time Reduction ◽  
The Brain ◽  
Cholinergic Neurotransmitter

SummarySerotonin seems to play an important role in the regulation of dopaminergic and cholinergic neurotransmitter activities. In patients with Parkinsons' Disease, serotonergic activity is generally reduced, which is considered a compensating mechanism for the reduced dopaminergic activity. At the same time, reduction of serotonin activity may play a role in the expression of cognitive and affective symptoms. Functional intervention with serotonergic agents makes it possible to temporarily enhance or reduce the availability of serotonin in the brain. This will provide the opportunity to study motor, cognitive and affective symptoms in an integrated approach. This type of research has hardly been preformed in patients with Parkinson's Disease.

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