Introducing the brain: single neuron complexity (Introduction)

by David Turell , Thursday, September 28, 2023, 15:37 (420 days ago) @ David Turell

In C. elegans worm:

https://www.cell.com/current-biology/fulltext/S0960-9822(23)01168-5?dgcid=raven_jbs_aip...

"Animals generate a wide range of highly coordinated motor outputs, which allows them to execute purposeful behaviors. Individual neurons in the circuits that generate behaviors have a remarkable capacity for flexibility as they exhibit multiple axonal projections, transmitter systems, and modes of neural activity. How these multi-functional properties of neurons enable the generation of adaptive behaviors remains unknown. Here, we show that the HSN neuron in C. elegans evokes multiple motor programs over different timescales to enable a suite of behavioral changes during egg laying. Using HSN activity perturbations and in vivo calcium imaging, we show that HSN acutely increases egg laying and locomotion while also biasing the animals toward low-speed dwelling behavior over minutes. The acute effects of HSN on egg laying and high-speed locomotion are mediated by separate sets of HSN transmitters and different HSN axonal compartments. The long-lasting effects on dwelling are mediated in part by HSN release of serotonin, which is taken up and re-released by NSM, another serotonergic neuron class that directly evokes dwelling. Our results show how the multi-functional properties of a single neuron allow it to induce a coordinated suite of behaviors and also reveal that neurons can borrow serotonin from one another to control behavior."

Comment: a single neuron acts like a tiny brain. Any other single cell, metabolizing along, is very complex enough to give anyone pause to wonder how did it appear? The neuron does much more in that it produces instructive proteins as well as messages through synapses it modulates for varying strength of signaling.