McConnell's research focuses on understanding how neurons in the developing cerebral cortex are produced, differentiated, and connected to form functional circuits.

[1] McConnell also confirmed the hypothesis that asymmetric cell division, as determined by the orientation of the dividing progenitor's cleavage plane, regulates cortical development.

Her work elucidated the first molecular mechanism for this process, showing that asymmetrically inherited Notch proteins determine whether a new daughter cell will differentiate into a neuron or remain a neural progenitor.

McConnell's recent work has continued to outline the molecular mechanisms underlying neural differentiation,[4][5][6][7] neuronal migration[8][9] and axon guidance.

[21] McConnell is married to Richard Scheller, former chief scientific officer and head of therapeutics at 23andMe and the former executive vice president of research and early development at Genentech.