Altered patterns of evoked synaptic activity in cortical pyramidal neurons in feline ganglioside storage disease.

Postsynaptic potentials evoked by ventrolateral thalamic stimulation were recorded intracellularly from neurons in the precruciate cortex of GM1 mutants with HRP- or LY-loaded microelectrodes. Ganglioside-laden pyramidal neurons exhibiting somal distention and/or meganeurite formation were found to respond to thalamic stimulation with short duration IPSPs. Evoked EPSPs were recorded from two morphologically characterized large basket intrinsic neurons which deployed extensive intracortical axonal arborizations. These findings point to the preservation of intracortical inhibitory networks in the feline model of GM1 gangliosidosis, and to the possibility of abnormal integration of somadendritic inputs in ganglioside-laden pyramidal neurons.