Using the CNS neuron gene expression specificity metrics, we observed a reduction in the number of neuronal cell types associated with the different traits (Figure S9), suggesting that some of the signal was driven by core neuronal genes. For example, the association of telencephalon projecting excitatory neurons with intracranial volume (Figure S5) was not significant using the CNS neuron specificity metric (Figure S9). However, we found that multiple neuronal cell types remained associated with a number of traits. For example, we found that telencephalon projecting excitatory and projecting inhibitory neurons were strongly associated with schizophrenia, bipolar disorder, educational attainment and intelligence using both LDSC and MAGMA. Similarly, telencephalon projecting excitatory neurons were significantly associated with BMI, neuroticism, MDD, autism and anorexia using one of the two methods (Figure S9), while hindbrain neurons and cholinergic and monoaminergic neurons remained significantly associated with Parkinson’s disease (Figure S9).
