Anshu gave an overview of Interneuron functions (feedback & feedforward inhibition, network oscillations and synchrony, modulation of excitability, integration and cortical development and plasticity) and then highlighted the complexity of internuron types (classified based on morphological, molecular, electrophysiological properties - eg Markram 2004).
She then discussed the role of GABAergic neurons in the pathophysiology of Schizophrenia and then Autism from post-mortem studies and animal models (gene knockouts) while showing that GABA impairment seems to be present in a wide variety of neuropsychiatric disorders. She then went through the mechanisms through which these interneurons modulate network oscillations via electrical gap junctions and neurochemical modulations amongst the interneurons (for example Parvalbumin expressing basket cells impact gamma oscillations while somatostatin expressing interneurons impact beta oscillations).
Considering that the type of impairment is similar for schizophrenia and autism, the timing of the impairment seems to be a differentiator between these two disorders. Autism is seen in early childhood (diagnosed around 3 years of age when neuronal pruning is still ongoing) and the first onset of Schizophrenia happens in adolescence (when the neurons are fully formed but the myelination is still an ongoing process).