Long-lasting, subtype-specific regulation of somatostatin interneurons during sensory learning

Somatostatin (SST)-expressing inhibitory neurons are a major class of
neocortical gamma-amino butyric acid (GABA) neurons, where morphological,
electrophysiological, and transcriptomic analyses indicate more than a
dozen different subtypes. However, whether this diversity is related to
specific roles in cortical computations and plasticity remains unclear.
Here we identify learning-dependent, subtype-specific plasticity in layer
2/3 somatostatin neurons of the mouse somatosensory cortex.
Martinotti-type, somatostatin neurons expressing calbindin-2 show a
selective decrease in excitatory synaptic input and stimulus-evoked
calcium responses as mice learn a stimulus-reward association. Using these
insights, we develop a label-free classifier using basal activity from in
vivo imaging that accurately predicts learning-associated response
plasticity. Our data indicate that molecularly-defined SST neuron subtypes
play specific and highly-regulated roles in sensory information processing
and learning.