Telencephalon astrocytes ACTE1 and ACTE2 were distinguished by the expression of several genes, including Mfge8 and Lhx2, and were found in the olfactory bulb, cerebral cortex, striatum, amygdala, and hippocampus but were absent from the hypothalamus, thalamus, midbrain, and hindbrain. Non-telencephalic astrocytes ACNT1 and ACNT2 showed the opposite distribution, marked by Agt (Angiotensinogen) and found in all regions caudal to the telencephalon/diencephalon border (i.e., posterior to and including the hypothalamus and thalamus). The border between the two was sharp, as judged by ISH of the relevant genes (Figure S2D), indicating that they do not intermingle across substantial distances.
