The Butt lab’s latest study on the role that cortical interneurons play in regulating sensory responses in the developing postnatal brain has been published in Cell Reports. The team are only one of two groups – alongside the collaborative network of Kevin Franks and Liqun Luo, to use optotagging to successfully identify the contribution of neurons to formative activity on the millisecond timescale. They are the first to resolve the contribution of GABAergic interneuron subtypes to spindle burst activity – early spontaneous events, as well as sensory-evoked responses across primary somatosensory and visual cortex. Their findings reveal that subtle differences in the diversity of somatostatin-expressing interneuron subtypes across these two sensory areas results in distinct local circuits that reflect the biological needs of the developing pup. Put simply, neonatal mice first experience the world through touch and have evolved a specialised, transient somatostatin interneuron circuit to control and regulate information transfer in somatosensory cortex from birth. This resource-expensive circuit is not required visual cortex as eye opening is delayed to the second postnatal week.
Simon Butt comments, 'our findings reveal that the physiological scaffolds that direct and constrain early activity, differ across cortical areas. This suggests that genetic/molecular programmes responsible for circuit formation and emergent function also vary; a finding that has significant implications for our understanding of the aetiology of neurodevelopmental psychiatric disorders.'
The work was led by Filippo Ghezzi (Wellcome Trust funded DPhil student) and Drs. Liad Baurchin and Nesta Ngoc Ha, with support from the BBSRC and MRC.
Read the paper here