Aversive operant conditioning alters the phototactic orientation of the marbled crayfish

Abstract

Aversive learning was applied to affect the phototactic behaviour of the marbled crayfish. Animals initially showed negative phototaxis to white light and positive taxis to blue light. Using an aversive learning paradigm, we investigated the plasticity of innate behaviour following operant conditioning. The initial rate of choosing a blue-lit exit was analysed by a dual choice experiment between blue-lit and white-lit exits in pre-test conditions. During training, electrical shocks were applied to the animals when they oriented to the blue-lit exit. Memory tests were given to analyse the orientation rate to the blue-lit exit in trials 1 h and 24 h after training and these rates were compared with the pre-test. In general, animals avoided the blue-lit exit in the memory tests. When training was done three times, the long-term memory was retained for at least 48 h, although a single bout of training was also enough to form a long-term memory. Cooling animals at 4 °C or injection of cycloheximide immediately after training altered the formation of long-term memory, but had no effect on short-term memory formation. Administration of the adenylate cyclase inhibitor SQ22536, the PKA inhibitor H89, or the CREB inhibitor KG-501 immediately after training also blocked the formation of long-term memory, but had no effect on short-term memory formation. Thus, our pharmacological behavioural analyses showed that new protein synthesis was necessary to form long-term memories and that the cAMP/PKA/CREB pathway is the main signal cascade for long-term memory formation in the marbled crayfish.

Effects of Acetic Acid and Morphine in Shore Crabs, Carcinus maenas: Implications for the Possibility of Pain in Decapods

“…Nevertheless, there is a body of studies on potential pain in decapods that test various criteria for pain, and these too have fulfilled those criteria and thus are also consistent with the idea of pain. For example, we see swift avoidance learning [ 38 , 39 , 40 ]. There are trade-offs between avoidance of a noxious stimulus and other motivational requirements, such as hermit crabs, Pagurus bernhardus , accepting electric shock to keep high-quality shells [ 41 , 42 ], or to avoid predators [ 43 ].…”

“…Further, shore crabs accept electric shocks to avoid bright but not dull light [ 39 ]. Following electric shocks, decapods show signs of anxiety [ 40 , 44 , 45 ] and show physiological stress responses after electric shocks [ 44 , 45 , 46 ] or injury [ 27 ]. Hermit crabs that are shocked within their shells show long-term reduction in their motivation to retain that shell (24 h) [ 47 ].…”

Combining Old and New Tricks: The Study of Genes, Neurons, and Behavior in Crayfish

“…Early work focused on the development of the nervous system and some of its neurotransmitters ( Vilpoux et al, 2006 ; Polanska et al, 2007 ; Fabritius-Vilpoux et al, 2008 ; Rieger and Harzsch, 2008 ). More recently, studies have investigated adult neurogenesis ( Brenneis et al, 2021 ), operant conditioning ( Okada et al, 2021 ), phototaxis ( Shiratori et al, 2017 ), and psychostimulant actions on marbled crayfish behavior ( Jackson and van Staaden, 2019 ). However, most of these studies used traditional non-genetic methods.…”

Behavioural Indicators of Pain and Suffering in Arthropods and Might Pain Bite Back?

“…However, if the former resulted in electric shock, the preference was switched, in the short-term, after just one exposure to shock. Further, three exposures resulted in avoidance that lasted for 48 h [ 26 ]. Long-term avoidance was not observed, however, if the animal was subsequently kept at low temperatures or was given protein-formation inhibitors, suggesting that long-term memory was inhibited.…”