Form and function: adapting dendritic morphology and synaptic location to optimise neural activity

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Neurons have remarkable morphologies, with elaborately branching dendrites and precisely placed synapses. What determines the shape of neurons? To what extent can their anatomy be tuned to optimise neuronal physiology? We address this question in the fruit fly Drosophila, where olfactory associative memories are stored in neurons called Kenyon cells. Our recent modelling work predicts that, to maximise memory capacity, all Kenyon cells should be equally excitable, and that achieving equal activity despite their variable intrinsic excitability requires compensatory variability (e.g., Kenyon cells with higher-than-usual spiking thresholds also have stronger-than-usual synaptic inputs). Do Kenyon cells tune their morphology to compensate for variability in other parameters? For example, a Kenyon cell with lower-than-usual spiking threshold might reduce its excitability by lengthening/narrowing its dendrites or placing excitatory synapses more distally, so that input signals weaken before they reach the spike initiation zone.