There have been a number of studies regarding the behavior of Elysia species, especially in the context of optimizing exposure for photosynthesis.  Studies of the nervous system are rather rare, however.

Miyamoto, A., Sakai, A., Nakano, R., Yusa, Y. Phototaxis of sacoglossan sea slugs with different photosynthetic abilities: a test of the ‘crawling leaves’ hypothesis. (2015) Marine Biology, 162 (6), pp. 1343-1349. [Tr] [Ha] [K] [BN]

Rasher, D.B., Stout, E.P., Engel, S., Shearer, T.L., Kubanek, J., Hay, M.E., Wootton, J.T. (2015) Marine and terrestrial herbivores display convergent chemical ecology despite 400 million years of independent evolution. (2015) Proceedings of the National Academy of Sciences of the United States of America, 112 (39), pp. 12110-12115. [F] [Tu] [BN] [NP] [K]

Schmitt, V., Wägele, H. (2011) Behavioral adaptations in relation to long-term retention of endosymbiotic chloroplasts in the sea slug Elysia timida (Opisthobranchia, Sacoglossa). Thalassas, 27 (2), pp. 225-238. PDF [BN] [K] [Ti]

Middlebrooks, M.L., Pierce, S.K., Bell, S.S. (2011) Foraging behavior under starvation conditions is altered via photosynthesis by the marine gastropod, Elysia clarki. PLoS ONE, 6 (7), art. no. e22162.  PDF [BN] [K] [Cl]

Schmitt, V., Anthes, N., Michiels, N.K. (2007) Mating behaviour in the sea slug Elysia timida (Opisthobranchia, Sacoglossa): Hypodermic injection, sperm transfer and balanced reciprocity. Frontiers in Zoology, 4, art. no. 17. [B] PDF [BN] [NH] [Ti]

Jensen, K.R. (1999) Copulatory behaviour in three shelled and five non-shelled sacoglossans (Mollusca, Opisthobranchia), with a discussion of the phylogenetic significance of copulatory behavior. Ophelia, 51 (2), pp. 93-106. PDF [BN] [NH] [Au] [Fi] [Le] [Tr]

Huber, G. (1993) on the cerebral nervous system of marine heterobranchia (gastropoda). J. Moll. Stud. 59: 381-420 [BN] [Vi]

Quinn, R.H., Pierce, S.K. (1992) The ionic basis of the hypo-osmotic depolarization in neurons from the opisthobranch mollusc Elysia chlorotica. Journal of Experimental Biology, 163, pp. 169-186.  PDF [BN] [Ch]

Parker, H.T., Pierce, S.K. (1985) Comparative electrical properties of identified neurons in Elysia chlorotica before and after low salinity acclimation. Comparative Biochemistry and Physiology — Part A: Physiology, 82 (2), pp. 367-372.  Abstract [BN] [Ch]

Weaver, S., Clark, K.B. (1981) Light intensity and color preferences of five Ascoglossan = Sacoglossan) molluscs (Gastropoda: Opisthobranchia): a comparison of chloroplast symbiotic and aposymbiotic species.  Marine Behavior and Physiology, 7 pp. 297-306 Abstract [Bn] [K] [Cr] [Tu]

Rahat, M., Monelise, E.B. (1979) Photobiology of the chloroplast hosting mollusc Elysia timida. Journal of Experimental Biology 79, pp. 225-233.  PDF [BN] [K] [Ti]

Russell, L. (1929) The comparative morphology of the Elysioid and Aeolidioid types of the molluscan nervous system, and its bearing on the relationships of the Ascoglossan nudibranchs. Proc. Zool. Soc. Lond. 14: 197-233.  [BN] [Vi]