S. P. and P. K. analyzed the data and wrote the article. Conflict of Interest The authors have no conflict of interest to declare. Supporting Information Additional Supporting Information may be found in the online version of this article: Figure S1. Data plotted per animal. Each point at each gap distance is from one animal. The number of attempts for control Inhibitors,research,lifescience,medical (A) and P0 (B) animals. The duration of an attempt in control (C) and P0 (D) animals. Error bars show mean ± SEM. Not all animals crossed

at all gap distances (Control: n = 12; P0: n = 15). Click here to view.(26K, pdf) Click here to view.(142K, png) Click here to view.(596 bytes, txt)
Researchers investigating associative learning in invertebrates have made significant breakthroughs in understanding

Inhibitors,research,lifescience,medical the conditioning process in animals like Aplysia and honey bees (Couvillon and Bitterman 1980; CCI-779 order Kandel and Schwartz 1982; Burmeitser et al. 1995). Studying invertebrate learning systems provides the opportunity to ask complex questions in relatively Inhibitors,research,lifescience,medical simple systems, as compared with vertebrates. An area of particular interest is the role of conditioning in learning through changes in behavior. Behavior is modulated by experience, through the acquisition of new information (learning) about the environment. Thus, instinctive behaviors can be modified based on the information provided in the environment. Several invertebrate studies show that these organisms modify Inhibitors,research,lifescience,medical their behavior, especially avoidance behavior. This is seen in mollusks with habituation of the rapid gill withdrawal reflex (Castellucci and Kandel 1974), food aversion with electric shock (Mpitsos and Davis 1973; Mpitsos and Collins 1975), and CO2 poisoning (Gelperin 1975). One

technique to demonstrate learning is using studies of operant learning, specifically the animal’s ability to Inhibitors,research,lifescience,medical complete a task. A key study showed that Carcinus maenas (a crab) are able to perform a lever-press motor task (Abramson and Feinman 1990). Precise manipulation of appendages is a powerful behavior in learning abilities because it tests the degree to which manipulative and motor behaviors are part of paradigm motor command. This is especially interesting given our developing knowledge all of neural circuitry and neuronal control in decapods such as crayfish and lobster (Krasne 1969; Davis 1970; Larimer et al. 1971). Learning and memory formation are important in the natural environment and this is especially true for social animals, because many social hierarchies depend on recognition. As seen with many crustaceans, agonistic outcomes between conspecifics create a history of social experience that can influence future behavior (Goessmann et al. 2000; Daws et al. 2002; Bergman et al. 2003). Studies in mollusks have shown that they use sign or goal tracking (Kemenes and Benjamin 1989; Purdy et al. 1999).