"Post-embryonic remodeling of the C. elegans motor circuit" by Ben Mulcahy et al. 2022 (Mei Zhen's lab https://zhenlab.com/)
... in which the authors show, using #vEM and #connectomics, that while the nematode #celegans nervous system grows from ~200 neurons in the hatchling to ~300 in the adult, the addition of new neurons doesn't disrupt existing motor function, but new circuits are formed that endow the animal with new behaviors such as bending.
Interestingly, in the course of larval maturation one neuron type inverts its polarity: what was the dendrite becomes the axon, and viceversa. And this is accomplished not with retraction and regrowth of the arbor, but rather, by flipping the synapses in situ.
@albertcardona
A bidirectional neuron, like the Tartan Prancer.
https://www.youtube.com/watch?v=tojXcpnYScM