Organisms are designed to engage three basic functions: resource acquisition, defense against accident (e.g., predation and disease), and reproduction. Their lifestyles represent economic strategies, and range in complexity from very simple solitary foraging to the complicated, multi-layered economies of the social vertebrates. The complexities of valuation, decision-making, and lifestyles are parallel over this range. What are the gradations of complexity in behavioral economy, and how are they traversed in evolution?

We describe neuronal circuitry for cost-benefit decisions in foraging behavior of the predatory sea-slug Pleurobranchaea and reproduce it in simulation. The computations resemble those of the most primitive parts of the mammal’s brain, onto which higher consciousness was grafted in evolution. We study the animal’s simple brain and behavior to understand the origins of the esthetic sense, reward experience, and addiction. How did the complexity for social behavior, abstract thought, and self-awareness evolve from the simpler brain?

We combine behavioral analyses, neurophysiological techniques, and computational modeling in an integrated approach to understanding how complex brains evolved from simple ones. A new research thrust analyzes sensory-motor computations of the peripheral nervous systems in Pleurobranchaea and the octopus to understand the coordination of behavior in animals without articulated skeletons, and how nervous system complexity evolved from simplicity.

We produce interactive computational simulations of foraging in virtual entities that make realistic economic decisions by weighing stimulus characters against motivation, and reward learning. Two may be freely accessed for experimentation from https://github.com/Entience/Cyberslug and https://github.com/Entience/ASIMOV. The recent version, ASIMOV, illustrates the emergence of addiction processes from the neuronal circuitry of foraging.

Recent Publications

Gribkova ED, Lee CA, Brown JW, Cui J, Liu Y, Norekian T, Gillette R (2023) A common modular design of nervous systems originating in soft-bodied invertebrates. Frontiers in Physiology 14:1263453. DOI=10.3389/fphys.2023.1263453.

Lee CA, Brown JW, Gillette R. Coordination of Locomotion by Serotonergic Neurons in the Predatory Gastropod Pleurobranchaea californica. J Neurosci. 2023 Apr 24:JN-RM-1386-22. doi: 10.1523/JNEUROSCI.1386-22.2023. Epub ahead of print. PMID: 37094932.

Gribkova, E.D., Gillette, R. Role of NMDAR plasticity in a computational model of synaptic memory. Scientific Reports 11, 21182 (2021). https://doi.org/10.1038/s41598-021-00516-y

Heng-Sheng Chang H-S, Udit Halder U, Chia-Hsien Shih C-H, Arman Tekinalp A, Tejaswin Parthasarathy T, Ekaterina Gribkova E, Girish Chowdhary G, Rhanor Gillette R, Mattia Gazzola M, Prashant G. Mehta PG (2020) Energy Shaping Control of a CyberOctopus Soft Arm. 2020 59th IEEE Conference on Decision and Control (CDC) arXiv:2004.05747v1 [eess.SY]

Clark K, Lee C, Gillette R, Sweedler J. (2021) Characterization of Neuronal RNA Modifications during Non-Associative Learning in Aplysia Reveals Key Roles for tRNAs in Behavioral Sensitization. ACS Central Science 2021 Jul 28;7(7):1183-1190. doi: 10.1021/acscentsci.1c00351. Epub 2021 Jul 18. PMID: 3434566

Lee CA, Romanova EV, Southey BR, Gillette R and Sweedler JV (2021) Comparative Analysis of Neuropeptides in Homologous Interneurons and Prohormone Annotation in Nudipleuran Sea Slugs. Frontiers in Physiology 12:809529. doi: 10.3389/fphys.2021.809529

Kaufman CD, Liu SC, Cvetkovic C, Lee CA, Naseri Kouzehgarani G, Gillette R, Bashir R, Gillette MU (2020) Emergence of functional neuromuscular junctions in an engineered, multicellular spinal cord-muscle bioactuator. APL Bioengineering 4, 026104 (2020); https://doi.org/10.1063/1.5121440

Gribkova, E.D., Catanho, M. & Gillette, R. Simple Aesthetic Sense and Addiction Emerge in Neural Relations of Cost-Benefit Decision in Foraging. Scientific Reports 10, 9627 (2020). https://doi.org/10.1038/s41598-020-66465-0

Rajagopal MC, Brown JW, Gelda D, Valavala KV, Wang H, Llano DA, Gillette R, Sinha S. (2019) Transient heat release during induced mitochondrial proton uncoupling. Communications Biology 2019 Jul 26;2:279. doi: 10.1038/s42003-019-0535-y. PMID: 31372518; PMCID: PMC6659641.

Brown JW, Caetano-Anollés D, Catanho M, Gribkova E, Ryckman N, Tian K, Voloshin M, Gillette R (2018) Implementing goal-directed foraging decisions of a simpler nervous system in simulation. eNeuro 26 February 2018, 5 (1) ENEURO.0400-17.2018; DOI: https://doi.org/10.1523/ENEURO.0400-17.2018

Green DJ, Huang RC, Sudlow L, Hatcher N, Potgieter K, McCrohan C, Lee C, Romanova EV, Sweedler JV, Gillette MLU, and Gillette, R. (2018). cAMP, Ca²⁺, pH_i, and NO regulate H-like cation channels that underlie feeding and locomotion in the predatory sea slug Pleurobranchaea californica. ACS Chemical Neuroscience, 9(8), 1986-1993. https://doi.org/10.1021/acschemneuro.8b00187

Brown JW, Schaub BM, Klusas BL, Tran AX, Duman AJ, Haney SJ, Boris AC, Flanagan MP, Delgado N, Torres G, Rolón-Martínez S, Vaasjo LO, Miller MW, Gillette R. A role for dopamine in the peripheral sensory processing of a gastropod mollusk. PLOS ONE, in press, 2018.

Gillette R, Brown JW. The Sea Slug, Pleurobranchaea californica: A signpost species in the evolution of complex nervous systems and behavior. Integr Comp Biol. 2015 Dec;55(6):1058-69. https://doi.org/10.1093/icb/icv081.  

Hirayama K, Moroz LL, Hatcher NG, Gillette R (2014) Neuromodulatory Control of a Goal-Directed Decision. PLoS ONE 9(7): e102240. doi:10.1371/journal.pone.0102240.

 Gillette R (2014) Pleurobranchaea. Scholarpedia. http://www.scholarpedia.org/article/Pleurobranchaea.  Curator: Prof. Rhanor Gillette. Published November 13, 2014.

Noboa V and Gillette R. Selective prey avoidance learning in the predatory sea-slug Pleurobranchaea californica. J. Exp. Biol. 216:3231-3236. https://doi.org/10.1242/jeb.079384.

Hirayama K, Catanho M, Brown JW and Gillette R (2012) A core circuit module for cost/benefit decision. Front. Neurosci. 6:123. https://doi.org/10.3389/fnins.2012.00123