Molecular and genetic approaches for assaying human cell type synaptic connectivity

Prospective and post-hoc molecular identification of specific neuron types is essential for functional studies of cellular and synaptic properties. We demonstrate a thick brain slice mFISH technique applied to multi-patch-clamp recordings in human cortical slices obtained from neurosurgical-excised tissue to reveal the molecular and morpho-electric properties of synaptically connected neurons, both with and without prospective AAV based genetic labeling. This quadruple modality methodology should be extensible to other local brain circuits in many organisms.