Danielle Scarano is a student in the Master of Science in Physician Assistant Studies program at Stanford School of Medicine. She led the development of science instructional content and resources for Newsela, an educational technology platform for students grades 2-12. Danielle also served as the Foundational Science Lead at Brilliant.org, where she led the development of the site's foundational science courses and content. Prior to her time at Brilliant, Danielle helped establish a school in the Bay Area. As the founding science teacher at Summit Tamalpais, she developed a project-based learning curriculum that engages students in scientific inquiry.
Education & Certifications
Bachelor of Science, Duke University, Neuroscience (2016)
Controlling for activity-dependent genes and behavioral states is critical for determining brain relationships within and across species
JOURNAL OF COMPARATIVE NEUROLOGY
2021; 529 (12): 3206-3221
The genetic profile of vertebrate pallia has long driven debate on homology across distantly related clades. Based on an expression profile of the orphan nuclear receptor NR4A2 in mouse and chicken brains, Puelles et al. (The Journal of Comparative Neurology, 2016, 524, 665-703) concluded that the avian lateral mesopallium is homologous to the mammalian claustrum, and the medial mesopallium homologous to the insula cortex. They argued that their findings contradict conclusions by Jarvis et al. (The Journal of Comparative Neurology, 2013, 521, 3614-3665) and Chen et al. (The Journal of Comparative Neurology, 2013, 521, 3666-3701) that the hyperpallium densocellare is instead a mesopallium cell population, and by Suzuki and Hirata (Frontiers in Neuroanatomy, 2014, 8, 783) that the avian mesopallium is homologous to mammalian cortical layers 2/3. Here, we find that NR4A2 is an activity-dependent gene and cannot be used to determine brain organization or species relationships without considering behavioral state. Activity-dependent NR4A2 expression has been previously demonstrated in the rodent brain, with the highest induction occurring within the claustrum, amygdala, deep and superficial cortical layers, and hippocampus. In the zebra finch, we find that NR4A2 is constitutively expressed in the arcopallium, but induced in parts of the mesopallium, and in sparse cells within the hyperpallium, depending on animal stimulus or behavioral state. Basal and induced NR4A2 expression patterns do not discount the previously named avian hyperpallium densocellare as dorsal mesopallium and conflict with proposed homology between the avian mesopallium and mammalian claustrum/insula at the exclusion of other brain regions. Broadly, these findings highlight the importance of controlling for behavioral state and neural activity to genetically define brain cell population relationships within and across species.
View details for DOI 10.1002/cne.25157
View details for Web of Science ID 000646699800001
View details for PubMedID 33855704
View details for PubMedCentralID PMC8205984