Tunicate larvae have a non-reproductive gonadotropin-releasing hormone (GnRH) system with multiple ligands and receptor heterodimerization enabling complex regulation. In Ciona intestinalis type A larvae, one of the gnrh genes, gnrh2, is conspicuously expressed in the motor ganglion and nerve cord, which are homologous structures to the hindbrain and spinal cord, respectively, of vertebrates. The gnrh2 gene is also expressed in the proto-placodal sensory neurons, which are the proposed homologue of vertebrate olfactory neurons. Tunicate larvae occupy a non-reproductive dispersal stage, yet the role of their GnRH system remains elusive. In this study, we investigated neuronal types of gnrh2-expressing cells in Ciona larvae and visualized the activity of these cells by fluorescence imaging using a calcium sensor protein. Some cholinergic neurons and dopaminergic cells express gnrh2, suggesting that GnRH plays a role in controlling swimming behavior. However, none of the gnrh2-expressing cells overlap with glycinergic or GABAergic neurons. A role in motor control is also suggested by a relationship between the activity of gnrh2-expressing cells and tail movements. Interestingly, gnrh2-positive ependymal cells in the nerve cord, known as a kind of glia cells, actively produced Ca2+ transients, suggesting that active intercellular signaling occurs in the glia cells of the nerve cord.

In vertebrate embryos, dorsal midline tissues, including the notochord, the prechordal plate, and the floor plate, play important roles in patterning of the central nervous system, somites, and endodermal tissues by producing extracellular signaling molecules, such as Sonic hedgehog (Shh). In Ciona, hedgehog.b, one of the two hedgehog genes, is expressed in the floor plate of the embryonic neural tube, while none of the hedgehog genes are expressed in the notochord. We have identified a cis-regulatory region of hedgehog.b that was sufficient to drive a reporter gene expression in the floor plate. The hedgehog.b cis-regulatory region also drove ectopic expression of the reporter gene in the endodermal strand, suggesting that the floor plate and the endodermal strand share a part of their gene regulatory programs. The endodermal strand occupies the same topographic position of the embryo as does the vertebrate hypochord, which consists of a row of single cells lined up immediately ventral to the notochord. The hypochord shares expression of several genes with the floor plate, including Shh and FoxA, and play a role in dorsal aorta development. Whole-embryo single-cell transcriptome analysis identified a number of genes specifically expressed in both the floor plate and the endodermal strand in Ciona tailbud embryos. A Ciona FoxA ortholog FoxA.a is shown to be a candidate transcriptional activator for the midline gene battery. The present findings suggest an ancient evolutionary origin of a common developmental program for the midline structures in Olfactores.

Tunicate larvae have a non-reproductive GnRH system with multiple ligands and receptor heterodimerization enabling complex regulation. In the Ciona larva, one of the gnrh genes, gnrh2, is conspicuously expressed in the motor ganglion and nerve cord, which are homologous structures to the hindbrain and spinal cord, respectively, of vertebrates. The gnrh2 gene is also expressed in the proto-placodal sensory neurons, which are the proposed homologue of vertebrate olfactory neurons. The tunicate larvae occupy a non-reproductive dispersal stage, yet the roles of their GnRH system remain elusive. In this study, we investigated neuronal types of gnrh2-expressing cells in the Ciona larva and visualized activity of these cells by fluorescence imaging using a calcium sensor protein. Some cholinergic neurons as well as dopaminergic cells express gnrh2, suggesting that a role of GnRH in the control of swimming behavior. By contrast, none of the gnrh2-expressing cells overlap with glycinergic or GABAergic neurons. A role in the motor control is also suggested by correlation between activity of some gnrh2-expressing cells and tail movements. Interestingly, gnrh2-positive ependymal cells in the nerve cord, known as a kind of glia cells, actively produced Ca 2+transients, suggesting that neuroendocrine signaling occurs in glia cells of the nerve cord.

Purpose To retrospectively assess the feasibility, safety, renal function, technique efficacy rate, and survival of patients with clinical T3a renal cell carcinoma (RCC). Materials and methods Sixteen cryoablation sessions were performed in 14 patients (10 men; mean age, 69.8 ± 10.5 years; range, 49–90 years) with 14 clear cell T3a RCCs (mean, 3.3 ± 0.9 cm; range, 1.9–5.2 cm). One patient was on dialysis. Transcatheter arterial embolization was performed before cryoablation in 15 sessions. The primary endpoint was the technique efficacy rate. The secondary endpoints included feasibility, safety, renal function, and survival. Results Cryoablation was technically successful in all RCC cases. In two RCCs, cryoablation was performed twice because of local tumor progression. No major adverse events were observed. All patients were alive without metastases, with a median follow-up of 45 months (6−93 months). Complete response was achieved by cryoablation in 11 RCCs (78.6%). The primary and secondary technique efficacy rates were 77.1% and 84.4% at 1 year, 57.9% and 73.9% at 3 years, and 57.9% and 73.9% at 5 years, respectively. One patient underwent dialysis given a total contralateral nephrectomy due to another RCC 1 month after initial cryoablation and a total ipsilateral nephrectomy 46 months after initial cryoablation due to local progression. Except for two dialysis patients, of the 12 patients with a median follow-up of 41 months (6–93 months), none were on dialysis. Conclusion Cryoablation was safe and effective in T3a RCC, which mainly involved the renal venous branches and may represent an alternative treatment for inoperable patients.