Amylin-Calcitonin receptor signaling in the medial preoptic area mediates affiliative social behaviors in female mice.

Social animals actively engage in contact with conspecifics and experience stress upon isolation. However, the neural mechanisms coordinating the sensing and seeking of social contacts are unclear. Here we report that amylin-calcitonin receptor (Calcr) signaling in the medial preoptic area (MPOA) mediates affiliative social contacts among adult female mice. Isolation of females from free social interactions first induces active contact-seeking, then depressive-like behavior, concurrent with a loss of Amylin mRNA expression in the MPOA. Reunion with peers induces physical contacts, activates both amylin- and Calcr-expressing neurons, and leads to a recovery of Amylin mRNA expression. Chemogenetic activation of amylin neurons increases and molecular knockdown of either amylin or Calcr attenuates contact-seeking behavior, respectively. Our data provide evidence in support of a previously postulated origin of social affiliation in mammals.

Calcitonin receptor signaling in the medial preoptic area enables risk-taking maternal care.

Maternal mammals exhibit heightened motivation to care for offspring, but the underlying neuromolecular mechanisms have yet to be clarified. Here, we report that the calcitonin receptor (Calcr) and its ligand amylin are expressed in distinct neuronal populations in the medial preoptic area (MPOA) and are upregulated in mothers. Calcr+ MPOA neurons activated by parental care project to somatomotor and monoaminergic brainstem nuclei. Retrograde monosynaptic tracing reveals that significant modification of afferents to Calcr+ neurons occurs in mothers. Knockdown of either Calcr or amylin gene expression hampers risk-taking maternal care, and specific silencing of Calcr+ MPOA neurons inhibits nurturing behaviors, while pharmacogenetic activation prevents infanticide in virgin males. These data indicate that Calcr+ MPOA neurons are required for both maternal and allomaternal nurturing behaviors and that upregulation of amylin-Calcr signaling in the MPOA at least partially mediates risk-taking maternal care, possibly via modified connectomics of Calcr+ neurons postpartum.

Plant-Specific Domains and Fragmented Sequences Imply Non-Canonical Functions in Plant Aminoacyl-tRNA Synthetases.

Aminoacyl-tRNA synthetases (aaRSs) play essential roles in protein translation. In addition, numerous aaRSs (mostly in vertebrates) have also been discovered to possess a range of non-canonical functions. Very few studies have been conducted to elucidate or characterize non-canonical functions of plant aaRSs. A genome-wide search for aaRS genes in Arabidopsis thaliana revealed a total of 59 aaRS genes. Among them, asparaginyl-tRNA synthetase (AsnRS) was found to possess a WHEP domain inserted into the catalytic domain in a plant-specific manner. This insertion was observed only in the cytosolic isoform. In addition, a long stretch of sequence that exhibited weak homology with histidine ammonia lyase (HAL) was found at the N-terminus of histidyl-tRNA synthetase (HisRS). This HAL-like domain has only been seen in plant HisRS, and only in cytosolic isoforms. Additionally, a number of genes lacking minor or major portions of the full-length aaRS sequence were found. These genes encode 14 aaRS fragments that lack key active site sequences and are likely catalytically null. These identified genes that encode plant-specific additional domains or aaRS fragment sequences are candidates for aaRSs possessing non-canonical functions.

Comparison of respiratory sparing effect between pancuronium and three new nondepolarizing muscle relaxants in rats.

PURPOSE: There is a large difference in sensitivity between respiratory muscles and other limb muscles. This phenomenon, known as the respiratory sparing effect (RSE), is well established withd-tubocurarine, pancuronium, and succinylcholine. The purpose of this study is to evaluate the RSE of these new relaxants, vecuronium, pipecuronium, and ORG9426. METHODS: The study was done in vivo using rats. Mechanical twitch responses of tibialis anterior muscle and diaphragm stimulated with the sciatic nerve and phrenic nerve, respectively, were recorded simultaneously to monitor neuromuscular transmission. Changes of mechanical twitch responses from both muscles were compared following the injection of four kinds of muscle relaxants (pancuronium, picuronium, recuronium, and ORG9426). RESULTS: T, D (%) represents the maximum depression in tibialis anterior and diaphragm, respectively. T-D (%), which means the sensitivity difference between the two kinds of muscle, was calculated by subtracting D from T. The T-Ds of pancuronium, pipecuronium, vecuronium, and ORG9426 were 86.0±2.6%, 81.4±1.9%, 77.7±2.1%, and 74.6±2.7%, respectively. CONCLUSIONS: The results indicated that the blockade produced by each muscle relaxant was lower in the diaphragm than in the anterior tibialis muscle. T-D was significantly smaller with vecuronium or ORG9426 than with pancuronium.

Comparison of sprotte and Quincke needles with respect to spinal fluid leakage using artificial spinal cord.

PURPOSE: This research investigated whether the Sprotte needle causes less leakage of CSF than the Quincke needle in the artificial spinal cord. METHODS: The changes in intradural pressure, extradural pressure, and leaked volume of CSF were evaluated following puncture with Sprotte and Quincke needles in the artificial spinal cord. RESULTS: The decrease in intradural pressure was 9.7±1.8 mm H2O with the Sprotte needle and 20.5±2.7 mm H2O with the Quincke needle (P<0.05). The volume of leakage of artificial CSF was 2.0±0.3 ml with the Sprotte needle and 3.3 ±0.3 ml with the Quincke needle (P<0.01). The extradural pressure increase was 166.1±8.2 mm H2O with the Sprotte needle and 186.8±13.2 mm H2O with the Quincke needle (P<0.05). CONCLUSION: The Sprotte needle produces less CSF leakage than the Quincke needle.