Functional consequences of animal-to-animal variation in circuit parameters

How different are the neuronal circuits for a given behavior across individual animals? To address this question, we measured multiple cellular and synaptic parameters within individual preparations to see how they correlate with circuit function, using neurons and synapses within the pyloric circuit of the stomatogastric ganglion (STG) of the crab Cancer borealis. There was considerable preparation-to-preparation variability in the strength of two identified synapses, in the amplitude of a modulator-evoked current, and in the expression of six ion channel genes. Nonetheless, across preparations we found strong correlations among these parameters and attributes of circuit performance. These data illustrate the importance of making multidimensional measurements from single preparations to understand how variability in circuit output is related to the variability of multiple circuit parameters.