Functional subtypes of synaptic dynamics in mouse and human

• Published in: Cell reports (Cambridge) 2024-02, Vol.43 (2), p.113785-113785, Article 113785
• Main Authors: Beninger, John, Rossbroich, Julian, Tóth, Katalin, Naud, Richard
• Format: Article
• Language: English
• Subjects: burst coding; cell types; CP: Cell biology; CP: Neuroscience; human physiology; machine learning; model-based characterization; neural coding; physiological calcium; short-term plasticity; synaptic physiology
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2024.113785

Synapses preferentially respond to particular temporal patterns of activity with a large degree of heterogeneity that is informally or tacitly separated into classes. Yet, the precise number and properties of such classes are unclear. Do they exist on a continuum and, if so, when is it appropriate to divide that continuum into functional regions? In a large dataset of glutamatergic cortical connections, we perform model-based characterization to infer the number and characteristics of functionally distinct subtypes of synaptic dynamics. In rodent data, we find five clusters that partially converge with transgenic-associated subtypes. Strikingly, the application of the same clustering method in human data infers a highly similar number of clusters, supportive of stable clustering. This nuanced dictionary of functional subtypes shapes the heterogeneity of cortical synaptic dynamics and provides a lens into the basic motifs of information transmission in the brain. [Display omitted] •Excitatory synaptic dynamics in cortex exist in distinct groups rather than on a continuum•Organization of cortical synaptic dynamics is more nuanced than facilitation and depression•Cell-type-specific differences are more resolvable at physiological calcium concentration•Subtypes partially align with transgenically defined subclasses Beninger et al. combine synaptic modeling and machine learning to infer the number and the characteristics of functional subtypes of cortical synaptic dynamics in humans and mice. These subtypes cannot be accounted for by continuum hypotheses, are similar between species, and partly overlap transgenic-associated types.