Prefrontal Cortex–Projecting Glutamatergic Thalamic Paraventricular Nucleus-Excited by Hypocretin: A Feedforward Circuit That May Enhance Cognitive Arousal

Huang, Hao; Ghosh, Prabhat K.; Pol, Anthony N. van den

doi:10.1152/jn.00927.2005

Cited by 133 publications

(100 citation statements)

References 76 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 F) and with previous reports of vGluT2 expression. Other positive cells were found in the cortex, amygdala, and thalamus (Huang et al, 2006). In contrast, neurons that were known to express vGluT1 and not vGluT2, for instance the CA3 pyramidal cells of the hippocampus (Fremeau et al, 2001), were negative for GFP in this transgenic mouse.…”

Section: Expression Of Gfp With Vglut2 Promoter In Neurons Of the Vmhmentioning

confidence: 73%

“…In these vGluT2 mice, GFP is selectively expressed in glutamatergic vGluT2-expresssing neurons but not in other cells. The sequence of the vGluT2 promoter construct used to drive GFP expression in these transgenic mice has been described previously (Huang et al, 2006). Briefly, the vGluT2 promoter, 1.8 kb upstream from the vGluT2 sequence, was used to drive GFP expression.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Agouti-Related Peptide and MC3/4 Receptor Agonists Both Inhibit Excitatory Hypothalamic Ventromedial Nucleus Neurons

Pol²

2008

J. Neurosci.

View full text Add to dashboard Cite

Anorexigenic melanocortins decrease food intake by activating MC3/MC4 receptors (MC3/4R); the prevailing view is that the orexigenic neuropeptide agouti-related peptide (AgRP) exerts the opposite action by acting as an antagonist at MC3/MC4 receptors. A total of 370 hypothalamic ventromedial nucleus (VMH) glutamatergic neurons was studied using whole-cell recording in hypothalamic slices from a novel mouse expressing green fluorescent protein (GFP) under control of the vesicular glutamate transporter 2 (vGluT2) promoter. Massive numbers of GFP-expressing VMH dendrites extended out of the core of the nucleus into the surrounding cell-poor shell. VMH dendrites received frequent appositions from AgRP-immunoreactive axons in the shell of the nucleus, but not the core, suggesting that AgRP may influence target VMH neurons. ␣-MSH, melanotan II (MTII), and selective MC3R or MC4R agonists were all inhibitory, reducing the spontaneous firing rate and hyperpolarizing vGluT2 neurons. The MC3/4R antagonist SHU9119 was excitatory. Unexpectedly, AgRP did not attenuate MTII actions on these neurons; instead, these two compounds showed an additive inhibitory effect. In the absence of synaptic activity, no hyperpolarization or change in input resistance was evoked by either MTII or AgRP, suggesting indirect actions. Consistent with this view, MTII increased the frequency of spontaneous and miniature IPSCs. In contrast, the mechanism of AgRP inhibition was dependent on presynaptic inhibition of EPSCs mediated by G i /G o -proteins, and was attenuated by pertussis toxin and NF023, inconsistent with mediation by G s -proteins associated with MC receptors. Together, our data suggest that the mechanism of AgRP actions on these excitatory VMH cells appears to be independent of the actions of melanocortins on MC receptors.

show abstract

Section: Expression Of Gfp With Vglut2 Promoter In Neurons Of the Vmhmentioning

confidence: 73%

Section: Methodsmentioning

confidence: 99%

Agouti-Related Peptide and MC3/4 Receptor Agonists Both Inhibit Excitatory Hypothalamic Ventromedial Nucleus Neurons

Pol²

2008

J. Neurosci.

View full text Add to dashboard Cite

show abstract

“…In any case, the rapid postnatal dendritic growth (Bicknell Jr and Beal 1984) and the predominance of tonic action potential discharge in young rat SDH neurons (Baccei and Fitzgerald 2005;) suggest that adult cell classification systems may be inappropriate. This issue could be addressed using selective green fluorescent protein-labeled transgenic mice (Daniele and MacDermott 2009;Huang et al 2006).…”

Section: Discussionmentioning

confidence: 99%

“…For example, the enhanced mEPSC rate could reflect the conversion of "silent" ("NMDAR only") synapses, which are present in the SDH during the first two postnatal weeks (Baba et al 2000;Bardoni et al 1998;Li and Zhuo 1998), to functional connections via the insertion of AMPARs into the postsynaptic membrane (Isaac et al 1997). However, the evidence suggests this is unlikely to explain the elevated mEPSC frequency after neonatal incision.…”

Section: Discussionmentioning

confidence: 99%

Activity-Dependent Modulation of Glutamatergic Signaling in the Developing Rat Dorsal Horn by Early Tissue Injury

Walker

Fitzgerald

et al. 2009

Journal of Neurophysiology

View full text Add to dashboard Cite

Li J, Walker SM, Fitzgerald M, Baccei ML. Activity-dependent modulation of glutamatergic signaling in the developing rat dorsal horn by early tissue injury. J Neurophysiol 102: 2208 -2219. First published August 12, 2009 doi:10.1152/jn.00520.2009. Tissue injury in early life can produce distinctive effects on pain processing, but little is known about the underlying neural mechanisms. Neonatal inflammation modulates excitatory synapses in spinal nociceptive circuits, but it is unclear whether this results directly from altered afferent input. Here we investigate excitatory and inhibitory synaptic transmission in the rat superficial dorsal horn following neonatal hindlimb surgical incision using in vitro patch-clamp recordings and test the effect of blocking peripheral nerve activity on the injuryevoked changes. Surgical incision through the skin and muscle of the hindlimb at postnatal day 3 (P3) or P10 selectively increased the frequency, but not amplitude, of glutamatergic miniature excitatory postsynaptic currents (mEPSCs) recorded 2-3 days after injury, without altering miniature inhibitory postsynaptic current frequency or amplitude at this time point. Meanwhile, incision at P17 failed to affect excitatory or inhibitory synaptic function at 2-3 days postinjury. The elevated mEPSC frequency was accompanied by increased inward rectification of evoked ␣-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-mediated currents, but no change in AMPAR/N-methyl-D-aspartate receptor ratios, and was followed by a persistent reduction in mEPSC frequency by 9 -10 days postinjury. Prolonged blockade of primary afferent input from the time of injury was achieved by administration of bupivacaine hydroxide or tetrodotoxin to the sciatic nerve at P3. The increase in mEPSC frequency evoked by P3 incision was prevented by blocking sciatic nerve activity. These results demonstrate that increased afferent input associated with peripheral tissue injury selectively modulates excitatory synaptic drive onto developing spinal sensory neurons and that the enhanced glutamatergic signaling in the dorsal horn following neonatal surgical incision is activity dependent.

show abstract

“…The processes that are regulated by the paraventricular thalamic nucleus, such as arousal and attention, as well as in the effects of stress on body temperature and energy balance (van der Werf et al, 2002;Kirouac et al, 2005;Bhatnagar and Dallman, 1999;Huang et al, 2006), have not been reported to be affected by 5-HT 7 receptor activation.…”

Section: Discussionmentioning

confidence: 99%

Expression of 5-HT7 receptor mRNA in the hamster brain: Effect of aging and association with calbindin-D28K expression

Duncan

Franklin

2007

Brain Research

View full text Add to dashboard Cite

Aging affects several processes modulated by the 5-HT 7 receptor subtype, including circadian rhythms, learning and memory, and depression. Previously, we showed that aging induces a decrease in the hamster dorsal raphe (DRN) in both 5-HT 7 receptor binding and circadian phase resetting responses to 8-OH-DPAT microinjection. To elucidate the mechanisms underlying the aging decrease in 5-HT 7 receptors, we investigated aging modulation of 5-HT 7 receptor mRNA expression in the DRN, brain regions afferent to the DRN, and brain regions regulating circadian rhythms or memory. In situ hybridization for 5-HT 7 receptor mRNA was performed on coronal sections prepared from the brains of young, middle-aged, and old male Syrian hamsters. 5-HT 7 receptor mRNA expression was quantified by densitometry of X-ray film autoradiograms. The results showed that aging did not significantly affect 5-HT 7 receptor mRNA expression in the DRN or most other brain regions examined, with the exception of the cingulate cortex and paraventricular thalamic nucleus. Within the suprachiasmatic nucleus, the site of the master circadian pacemaker in mammals, 5-HT 7 receptor mRNA expression was localized in a discrete subregion resembling the calbindin subnucleus previously described. A second experiment using adjacent tissue sections showed that 5-HT 7 receptor mRNA and calbindin mRNAs were concentrated in the same region of the SCN, and as well as in the same region of several other brain structures. The localization of 5-HT 7 receptors and calbindin mRNAs within the same regions suggests that proteins they encode may interact to modulate processes such as circadian timekeeping.

show abstract

Prefrontal Cortex–Projecting Glutamatergic Thalamic Paraventricular Nucleus-Excited by Hypocretin: A Feedforward Circuit That May Enhance Cognitive Arousal

Cited by 133 publications

References 76 publications

Agouti-Related Peptide and MC3/4 Receptor Agonists Both Inhibit Excitatory Hypothalamic Ventromedial Nucleus Neurons

Agouti-Related Peptide and MC3/4 Receptor Agonists Both Inhibit Excitatory Hypothalamic Ventromedial Nucleus Neurons

Activity-Dependent Modulation of Glutamatergic Signaling in the Developing Rat Dorsal Horn by Early Tissue Injury

Expression of 5-HT7 receptor mRNA in the hamster brain: Effect of aging and association with calbindin-D28K expression

Contact Info

Product

Resources

About