Differential alterations in the morphology and electrophysiology of layer II pyramidal cells in the primary visual cortex of a mouse model prenatally exposed to LPS.

Maternal inflammation is a known risk factor for schizophrenia and autism. Since the visual processing has shown abnormalities in these disorders, we explored whether neuropathologic changes can be caused in the primary visual cortex in offsprings due to the maternal inflammation induced by a single lipopolysaccharide (LPS) injection in pregnant mouse dams. The morphology and electrophysiological properties of layer II pyramidal cells (L2PC) in the primary visual cortex were investigated with whole-cell patch-clamping recording and 3D neuron reconstruction techniques. Although the composition of two L2PC types was unchanged, a reorganization of the dendritic architecture was found in both L2PC_A and L2PC_B types, predominantly in the L2PC_A type, of the mice prenatally exposed to LPS. Moreover, prenatal LPS exposure differentially altered intrinsic electrophysiological properties of the two L2PC types. L2PC_A neurons showed reduced excitability as featured by a hyperpolarization of the resting membrane potential, whereas L2PC_B neurons showed enhanced excitability as featured by a decrease in cellular input resistance at resting membrane potential. These significant changes in neuronal morphological and electrophysiological properties might contribute to the dysfunctions of pyramidal neurons after maternal inflammation.