While depression and chronic pain are frequently comorbid, underlying neuronal circuits and their psychopathological relevance remain poorly defined. Here we show in mice that hyperactivity of the neuronal pathway linking the basolateral amygdala to the anterior cingulate cortex is essential for chronic pain-induced depression. Moreover, activation of this pathway in naive male mice, in the absence of on-going pain, is sufficient to trigger depressive-like behaviors, as well as transcriptomic alterations that recapitulate core molecular features of depression in the human brain. These alterations notably impact gene modules related to myelination and the oligodendrocyte lineage. Among these, we show that Sema4a, which was significantly upregulated in both male mice and humans in the context of altered mood, is necessary for the emergence of emotional dysfunction. Overall, these results place the amygdalo-cingulate pathway at the core of pain and depression comorbidity, and unravel the role of Sema4a and impaired myelination in mood control.

The Phalangopsidae crickets (Grylloidea) of the Seychelles are examined following extensive field sampling on several main islands of the archipelago (Mahé, Silhouette, Praslin, La Digue). Despite the small area of these islands, six genera (12 species) are documented, including one new genus and five new species. The type species of the genus Seychellesia Bolivar, 1912 is transferred to the genus Paragryllodes Karny, 1909 as Paragryllodes nitidula (Bolivar, 1912) n. comb. The other species described in Seychellesia are transferred to the genus Seselia Hugel & Desutter-Grandcolas, n. gen., as Seselia longicercata (Bolivar, 1912) n. comb. and Seselia patellifera (Bolivar, 1912) n. comb. Two new species are also described in the genus Seselia Hugel & Desutter-Grandcolas, n. gen., Seselia coccofessei Hugel & Desutter-Grandcolas, n. gen., n. sp. (type species of the genus) and Seselia matyoti Hugel & Desutter-Grandcolas, n. gen., n. sp. The genera Phaeogryllus Bolivar, 1912 and Phalangacris Bolivar, 1895 are redescribed, including Phalangacris ferlegro Hugel & Desutter-Grandcolas, n. sp. and Phalangacris sotsote Hugel & Desutter-Grandcolas, n. sp. that are new to science. The genus Gryllapterus Bolivar, 1912 is redescribed and transferred from the Landrevinae (Gryllidae) to the Cachoplistinae (Phalangopsidae). New tribes are defined for the genus Paragryllodes (Paragryllodini Hugel & Desutter-Grandcolas, n. tribe) on the one hand, and for Seselia Hugel & Desutter-Grandcolas, n. gen., Phalangacris, Phaeogryllus and Gryllapterus (Seselini Hugel & Desutter-Grandcolas, n. tribe) on the other, using morphological characters and the results of molecular phylogenetic studies (Warren et al. 2019). Phaloria (Papuloria) insularis (Bolivar, 1912) (Phaloriinae) is redescribed and restricted to Mahé, and its calling song is documented for the first time, while Phaloria (Papuloria) bolivari Hugel & Desutter-Grandcolas, n. sp. is newly described from Silhouette. Identification keys are proposed for the genera of Seselini Hugel & Desutter-Grandcolas, n. tribe, and for the species of Seselia Hugel & Desutter-Grandcolas, n. gen. and Phalangacris. The confusion between the Mogoplistidae Ornebius succineus Bolivar, 1912 and the Phalangopsidae Heterotrypus succineus Bolivar, 1910 is discussed, and the name Subtiloria succineus (Bolivar, 1912) considered a nomen nudum.

Madagascar has a long history of using Orthoptera as food and feed. Our understanding of the biological diversity of this resource, its contemporary use, and its future potentials in Madagascar is extremely limited. The present study contributes basic knowledge of the biological diversity and local uses of edible Orthoptera in Malagasy food cultures. Data was collected with key informants in 47 localities covering most of the ecoregions of Madagascar and corresponding to 12 of the 19 ethnic groups. Orthoptera are consumed throughout Madagascar. We report 37 edible Orthoptera species, of which 28 are new species records of edible Orthoptera in Madagascar and 24 are new species records of edible Orthoptera in the world. Most species are endemic and occur in farming zones. Children are the primary collectors and consumers of edible Orthoptera. The insects are eaten both as snacks and main meals. Edible Orthoptera are primarily collected casually and marketing is rare, with the notable exceptions of the large cricket Brachytrupes membranaceus colosseus and during locust outbreaks (e.g., Locusta migratoria). The use of Orthoptera as feed seems rare. Further investigations of cultural and personal preferences are required to assess the future potential roles of Orthoptera in Malagasy food habits.