Brain-wide genetic mapping identifies the indusium griseum as a prenatal target of pharmacologically unrelated psychostimulants

Drug abuse during pregnancy carries significant risk for impaired fetal development. Here, we show that episodic exposure to amphetamine, nicotine, or caffeine during pregnancy induces various patterns of neuronal activity in the fetal brain. The indusium griseum, situated parallel to the central surface of the cortical hemispheres, is indiscriminately activated. Herein, psychostimulants preferentially target glutamatergic neurons and delay their differentiation. Particularly, expression of secretagogin, a Ca²⁺-sensor protein, is deregulated, which is significant because its loss impairs the integration of information that flows along limbic and olfactory circuits. Cumulatively, we describe psychostimulant-sensitive brain regions and unique neuronal subtypes whose developmental delay disrupts circuit wiring such that behavioral abnormalities can manifest in offspring prenatally exposed to psychostimulants.