Crosstalk between mitochondria, calcium channels and actin cytoskeleton modulates noradrenergic activity of locus coeruleus neurons.

Locus coeruleus (LC) is the name of a group of large sized neurons located at the brain stem, which provides the main source of noradrenaline to the central nervous system, virtually, innervating the whole brain. All noradrenergic signalling provided by this nucleus is dependent on an intrinsic pacemaker process. Our study aims to understand how noradrenergic neurons finely tune their pacemaker processes and regulate their activities.

Phasic contractions of the mouse vagina and cervix at different phases of the estrus cycle and during late pregnancy.

Background/aims: The pacemaker mechanisms activating phasic contractions of vaginal and cervical smooth muscle remain poorly understood. Here, we investigate properties of pacemaking in vaginal and cervical tissues by determining whether: 1) functional pacemaking is dependent on the phase of the estrus cycle or pregnancy; 2) pacemaking involves Ca2+ release from sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA) -dependent intracellular Ca2+ stores; and 3) c-Kit and/or vimentin immunoreactive ICs have a role in pacemaking.

Methodology/principal Findings: Vaginal and cervical contractions were measured in vitro, as was the distribution of c-Kit and vimentin positive interstitial cells (ICs).

Heterogeneous responses to antioxidants in noradrenergic neurons of the Locus coeruleus indicate differing susceptibility to free radical content.

The present study investigated the effects of the antioxidants trolox and dithiothreitol (DTT) on mouse Locus coeruleus (LC) neurons. Electrophysiological measurement of action potential discharge and whole cell current responses in the presence of each antioxidant suggested that there are three neuronal subpopulations within the LC. In current clamp experiments, most neurons (55%; 6/11) did not respond to the antioxidants.

Developmental changes in pacemaker currents in mouse locus coeruleus neurons.

The present study compares the electrophysiological properties and the primary pacemaker currents that flow during the interspike interval in locus coeruleus (LC) neurons from infant (P7-12 days) and young adult (8-12 weeks) mice. The magnitude of the primary pacemaker currents, which consist of an excitatory TTX-sensitive Na(+) current and an inhibitory voltage-dependent K(+) current, increased in parallel during development. We found no evidence for the involvement of hyperpolarization-activated (I(H)) or Ca(2+) currents in pacemaking in infant or adult LC neurons.

Ketamine anesthesia helps preserve neuronal viability.

The dissociative anesthetic ketamine that acts as an N-methyl-D-aspartate (NMDA) antagonist has been reported to improve neurological damage after experimental ischemic challenges. Here we show that deep anesthesia with ketamine before euthanasia by decapitation improves the quality of neonatal mouse neuronal brain slice preparations. Specifically we found that neurons of the locus coeruleus (LC) and hypoglossal motor neurons had significantly higher input resistances, and LC neurons that generally are difficult to voltage control, could be more reliably voltage clamped compared to control neurons.

Experimental hypothyroidism inhibits delta-aminolevulinate dehydratase activity in neonatal rat blood and liver.

The aim of this study was to investigate the potential relationship between hypothyroidism and delta-aminolevulinate dehydratase (delta-ALA-D) activity in rat blood and liver. Experimental hypothyroidism was induced in weanling rats by exposing their mothers to propylthiouracil (PTU) diluted in tap water (0.05% w/ v), ad libitum, during the lactational period (PTU group).

Effect of 2-deoxy-D-glucose on aminoacids metabolism in rats' cerebral cortex slices.

We studied the effect of different concentrations of 2-deoxy-D-glucose on the L-[U-14C]leucine, L-[1-14C]leucine and [1-14C]glycine metabolism in slices of cerebral cortex of 10-day-old rats. 2-deoxy-D-glucose since 0.5 mM concentration has inhibited significantly the protein synthesis from L-[U-14C]leucine and from [1-14C]glycine in relation to the medium containing only Krebs Ringer bicarbonate.