Burrell BD, Crisp KM. (2008). Serotonergic modulation of afterhyperpolarization in a neuron that contributes to learning in the leech. Journal of neurophysiology. 99 [PubMed]
Moss BL, Fuller AD, Sahley CL, Burrell BD. (2005). Serotonin modulates axo-axonal coupling between neurons critical for learning in the leech. Journal of neurophysiology. 94 [PubMed]