scholarly journals Rapid testosterone-induced growth of the medial preoptic nucleus in male canaries

2019 ◽  
Vol 204 ◽  
pp. 20-26 ◽  
Author(s):  
Olesya T. Shevchouk ◽  
Gregory F. Ball ◽  
Charlotte A. Cornil ◽  
Jacques Balthazart
Keyword(s):  
Preoptic Nucleus ◽  
Medial Preoptic Nucleus

The medial preoptic nucleus receives vasotocinergic inputs in male quail: a tract-tracing and immunocytochemical study

2002 ◽  
Vol 24 (1) ◽  
pp. 27-39 ◽  
Author(s):  
Philippe Absil ◽  
Monica Papello ◽  
Carla Viglietti-Panzica ◽  
Jacques Balthazart ◽  
GianCarlo Panzica
Keyword(s):  
Immunocytochemical Study ◽  
Preoptic Nucleus ◽  
Tract Tracing ◽  
Medial Preoptic Nucleus

Differential Control of Spontaneous and Evoked GABA Release by Presynaptic L-Type Ca2+ Channels in the Rat Medial Preoptic Nucleus

2010 ◽  
Vol 104 (1) ◽  
pp. 200-209 ◽  
Author(s):  
Evgenya Malinina ◽  
Michael Druzin ◽  
Staffan Johansson
Keyword(s):  
Time Course ◽  
Stimulus Frequency ◽  
Gaba Release ◽  
High Frequency Stimulation ◽  
Functional Coupling ◽  
Channel Blockers ◽  
Preoptic Nucleus ◽  
External Stimulation ◽  
Medial Preoptic Nucleus ◽  
Differential Control

To clarify the role of presynaptic L-type Ca2+ channels in GABA-mediated transmission in the medial preoptic nucleus (MPN), spontaneous, miniature, and impulse-evoked inhibitory postsynaptic currents (sIPSCs, mIPSCs, and eIPSCs, respectively) were recorded from MPN neurons in a slice preparation from rat brain. The effects of different stimulus protocols and pharmacological tools to detect contributions of L-type Ca2+ channels and of Ca2+-activated K+ (KCa) channels were analyzed. Block of L-type channels did not affect the sIPSC and mIPSC properties (frequency, amplitude, decay time course) in the absence of external stimulation but unexpectedly potentiated the eIPSCs evoked at low stimulus frequency (0.1–2.0 Hz). This effect was similar to and overlapping with the effect of KCa-channel blockers. High-frequency stimulation (50 Hz for 10 s) induced a substantial posttetanic potentiation (PTP) of the eIPSC amplitude and of the sIPSC frequency. Block of L-type channels still potentiated the eIPSC during PTP, but in contrast, reduced the sIPSC frequency during PTP. It was concluded that L-type channels provide a means for differential control of spontaneous and impulse-evoked GABA release and that this differential control is prominent during short-term synaptic plasticity. Functional coupling of the presynaptic L-type channels to KCa channels explains the observed effects on eIPSCs.

The medial preoptic nucleus as a site of the thermogenic and metabolic actions of melanotan II in male rats

2014 ◽  
Vol 307 (2) ◽  
pp. R158-R166 ◽  
Author(s):  
Boris Monge-Roffarello ◽  
Sebastien M. Labbe ◽  
Christophe Lenglos ◽  
Alexandre Caron ◽  
Damien Lanfray ◽  
...  
Keyword(s):  
Metabolic Effects ◽  
Male Rats ◽  
Hypothalamic Nucleus ◽  
Preoptic Nucleus ◽  
Iodothyronine Deiodinase ◽  
Interscapular Brown Adipose Tissue ◽  
Medial Preoptic Nucleus ◽  
Brown Adipose ◽  
A Site ◽  
Melanotan Ii

The present study was designed to investigate the role of the medial preoptic nucleus (MPO) as a site of the thermogenic and metabolic effects of the α-melanocyte-stimulating hormone analog melanotan II (MTII). We also assessed the involvement of the dorsomedial hypothalamic nucleus (DMH) by investigating the effects of the MPO infusion of MTII in rats with DMH lesions produced by kainic acid. Infusion of MTII in the MPO led to increases in interscapular brown adipose tissue (iBAT) temperature and iBAT uptake of 14C-bromopalmitate. Both increases were blocked by DMH lesions. iBAT temperature increase (area under curve) and 14C-bromopalmitate uptake emerged as two correlated variables ( r = 0.63, P < 0.001). DMH lesions also blocked MTII-induced expression of mRNAs coding for proteins involved in 1) thermogenesis [type II iodothyronine deiodinase ( Dio2) and peroxisome proliferator-activated receptor gamma coactivator 1-α ( Pgc1α)], 2) lipolysis [hormone-sensitive lipase ( Hsl)], and 3) lipogenesis [diacylglycerol-O-acyltransferase 2 ( Dgat2), fatty acid synthase ( Fas)], in iBAT of rats killed 1 h after MPO infusion of MTII. MTII also stimulated expression of genes in iWAT but only in rats with DMH lesions. These genes included glucose transporter member 4 ( Glut4), glycerol-3-phosphate acyltransferase 3 ( Gpat3), Dgat1, Dgat2, triglyceride lipase ( Atgl), Hsl, and carnitine palmitoyltransferase 1β ( Cpt1β). Altogether, the present results reveal the MPO as a site of the thermogenic and metabolic actions of MTII. They also contribute to establish the MPO-DMH duet as a significant target for melanocortins to modulate energy homeostasis.

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