part of part of organ part ascidian neural complex ascidian cerebral ganglion the CG appears to be a diencephalic brain. It originates mainly from the posterior sensory vesicle (Takamura 2002; Dufour et al. 2006) and shows endocrine activity. For examples, ascidian genes orthologous to GnRH and OT/VP, which are secreted from the hypothalamus and the NH, respectively, in vertebrates, are expressed in the cortex of the CG, suggesting that the NC is not distinctly compartmentalized as are vertebrate brains (Tsutsui et al. 1998; Kavanaugh et al. 2005; Kawada et al. 2008; Ukena et al. 2008; Kawada et al. 2009). Moreover, PC2 expression in the cortex of the CG supports possible endocrine activity (Sekiguchi et al. 2007). // Editor notes: consider merging into brain, based on http://www.ncbi.nlm.nih.gov/pubmed/21062451 "We suggest using the term brain not only for the 'dorsal ganglia' of adult Tunicata and Pterobranchia, but also for the larval 'cerebral ganglion' of tunicates." UBERON:0009862 Missing definition for term UBERON:0009862. Please replace it using linked reference.