Inhibitory interneurons regulate phasic activity of noradrenergic neurons in the mouse locus coeruleus and functional implications.

KEY POINTS: The locus coeruleus (LC) contains noradrenergic (NA) neurons that respond to novel stimuli in the environment with phasic activation to initiate an orienting response; phasic LC activation is also triggered by stimuli, representing the outcome of task-related decision processes, to facilitate ensuing behaviours and help optimize task performance. Here, we report that LC-NA neurons exhibit bursts of action potentials in vitro resembling phasic LC activation in vivo, and the activity is gated by inhibitory interneurons (I-INs) located in the peri-LC. We also observe that inhibition of peri-LC I-INs enhances prepulse inhibition and axons from cortical areas that play important roles in evaluating the cost/reward of a stimulus synapse on both peri-LC I-INs and LC-NA neurons. The results help us understand the cellular mechanisms underlying the generation and regulation of phasic LC activation with a focus on the role of peri-LC I-INs. ABSTRACT: Noradrenergic (NA) neurons in the locus coeruleus (LC) have global axonal projection to the brain. These neurons discharge action potentials phasically in response to either novel stimuli in the environment to initiate an orienting behaviour or stimuli representing the outcome of task-related decision processes to facilitate ensuing behaviours and help optimize task performance. Nevertheless, the cellular mechanisms underlying the generation and regulation of phasic LC activation remain unknown. We report here that LC-NA neurons recorded in brain slices exhibit bursts of action potentials that resembled the phasic activation-pause profile observed in animals. The activity was referred to as phasic-like activity (PLA) and was suppressed and enhanced by blocking excitatory and inhibitory synaptic transmissions, respectively. These results suggest the existence of a local circuit to drive PLA, and the activity could be regulated by the excitatory-inhibitory balance of the circuit. In support of this notion, we located a population of inhibitory interneurons (I-INs) in the medial part of the peri-LC that exerted feedforward inhibition of LC-NA neurons through GABAergic and glycinergic transmissions. Selective inhibition of peri-LC I-INs with chemogenetic methods could enhance PLA in brain slices and increase prepulse inhibition in animals. Moreover, axons from the orbitofrontal and prelimbic cortices, which play important roles in evaluating the cost/reward of a stimulus, synapse on both peri-LC I-INs and LC-NA neurons. These observations demonstrate functional roles of peri-LC I-INs in integrating inputs of the frontal cortex onto LC-NA neurons and gating the phasic LC output.

Acute abdomen in early pregnancy due to ovarian torsion following successful in vitro fertilization treatment.

OBJECTIVE: Ovarian torsion is an acute abdomen requiring prompt intervention. Ovarian torsion seldom occurs during pregnancy. However, with in vitro fertilization (IVF) treatments, ovarian hyperstimulation may increase the size of the ovaries and result in the occurrence of adnexal torsion. Here, we report two cases of ovarian torsion after IVF and discuss the optimal management of this emergency medical condition. CASE REPORT: The first case was a 23-year-old woman who received IVF-embryo transfer due to tubal factor infertility. Sudden-onset, lower abdominal pain developed at the 6th week of pregnancy. Conservative treatment with antibiotics was the initial approach, but a right oophorectomy had to be performed due to right ovarian torsion with hemorrhagic and gangrenous changes. The second case was a 38-year-old woman diagnosed with bilateral ovarian torsion at 8 weeks' gestation due to the sudden onset of low abdominal pain. Laparoscopy was arranged immediately after the diagnosis was confirmed. The left ovary was successfully preserved due to prompt intervention. Both pregnancies continued without problems after surgery. CONCLUSION: Ovarian hyperstimulation during IVF-embryo transfer treatment is a risk factor for developing adnexal torsion. Early diagnosis and prompt surgical intervention is the only way to protect the ovary and preserve the pregnancy. Laparoscopic surgery in early pregnancy causes no harm to the fetus and should be encouraged once the diagnosis is confirmed. Delaying surgery may induce serious infection and jeopardize the lives of both the fetus and mother.

Multidisciplinary examination for prenatal diagnosis of posterior cervical teratoma in early second trimester.

OBJECTIVE: Cervical teratomas represent approximately 3% of all congenital teratomas, which occur in approximately 1 in 20,000-40,000 live births. In this report, we present a case of congenital posterior cervical teratoma diagnosed by a two-dimensional (2D) ultrasound in the early second trimester. CASE REPORT: A 28-year-old woman, gravid 1, para 0, came to our prenatal clinic at 20 weeks of gestation for her first prenatal visit. Results of an ultrasound revealed a fetus with multiple cystic septal mass with internally calcified spots measuring approximately 3 cm over the left fetal neck. Because no other abnormality was noted at that time, magnetic resonance imaging (MRI) and amniocentesis were scheduled on the following day. At the same time, results of a 4D ultrasound revealed the mass size to be same as that measured by the 2D ultrasound; however, the location was defined on the left posterior neck and MRI showed there was no invasion to the intracranial area. The parents opted to continue the pregnancy. In the following prenatal cares, no polyhydramnios was found and the fetal body weight was within the normal growth curve. The baby was delivered by cesarean section at 38 weeks of gestation with Apgar scores of 8 (at 1 minute) and 9 (at 5 minutes). The baby was scheduled for surgical intervention 3 days after birth. Finally, results of a pathological analysis revealed the mass to be a benign cystic teratoma. CONCLUSION: Prenatal diagnosis of cervical teratoma is very crucial, allowing early detection of masses that obstruct the airway. Therefore, a multidisciplinary examination and follow-up are recommended for early prenatal diagnosis.

cDNA cloning and functional characterization of ETHYLENE INSENSITIVE 3 orthologs from Oncidium Gower Ramsey involved in flower cutting and pollinia cap dislodgement.

The cDNAs encoding ETHYLENE INSENSITIVE3 (EIN3) transcription factor, OgEIL1 and OgEIL2 of Oncidium were cloned, sequenced and characterized. The deduced amino acid sequences of OgEIL1 and OgEIL2 of identified cDNA clones contain all structural features found in the Arabidopsis EIN3, such as an amino terminal acidic domain, a proline-rich region, and five basic conserved domains. Complementation test for OgEIL1 in Arabidopsis ein3 mutant indicate that function of OgEIL1 is the same as Arabidopsis EIN3. RNA gel blot analysis indicated that OgEIL1 and OgEIL2 expressed differentially in the roots, stem, leaves and flower buds of Oncidium. OgEIL1 and OgEIL2 mRNA levels in fully opened flowers increased as time progressed after cutting and reached a maximum in the fifth day and decreased on seventh day, which is consistent with the hypothesis that flowers initiated to wilt when ethylene raised abruptly. In de-capped flowers, OgEIL2 mRNA showed a decrease, while OgEIL1 mRNA exhibited an increase. Exogenous application of ethylene increased the mRNA levels of OgEIL1 and OgEIL2 in flower buds and flowers after cutting compared prior to ethylene treatment, however, in pollinia de-capped flowers, both OgEIL1 and OgEIL2 mRNA levels responded to a decline to exogenous ethylene immediately after treatment. Collectively, it is suggested that the main functions of OgEIL1 and OgEIL2 are to modulate the senescence of Oncidium flowers.