What are the elements of motivation for acquisition of conditioned taste aversion?

Behavioural/motivational state is known to influence nearly all aspects of physiology and behaviour. The cellular basis of behavioural state control is only partially understood. Our investigation, performed on the pond snail Lymnaea stagnalis whose nervous system is useful for work on completely isolated neurons, provided several results related to this problem. First, we demonstrated that the behavioural state can produce long-term changes in individual neurons that persist even after neuron isolation from the nervous system. Specifically, we found that pedal serotonergic neurons that control locomotion show higher activity and lower membrane potential after being isolated from the nervous systems of hungry animals. Second, we showed that the modulatory state (the chemical neuroactive microenvironment of the central ganglia) changes in accordance with the nutritional state of an animal and produces predicted changes in single isolated locomotor neurons. Third, we report that observed hunger-induced effects can be explained by the increased synthesis of serotonin in pedal serotonergic neurons, which has an impact on the electrical activity of isolated serotonergic neurons and the intensity of extrasynaptic serotonin release from the pedal ganglia.

Section: Storage Of the Behavioural State In Completely Isolated Neuronsmentioning

confidence: 74%

The Activity of Isolated Neurons and the Modulatory State of an Isolated Nervous System Represent a Recent Behavioural State

Dyakonova

Hernádi

Ito

et al. 2015

“…The food-deprivation status is defined in the following manner: the day when snails begin food deprivation is called day 0. Day −1 snails are thus 'fed' snails; day 1 snails are the snails deprived of food for 1 day; and day 5 snails are snails food deprived for 5 days (Mita et al, 2014a).…”

Section: Results and Discussion Aversiveness Of Various Unconditionedmentioning

confidence: 99%

“…In addition to the use of the novel US, the Takigami study ) used a 100 mmol l −1 sucrose solution as the CS whereas in our previous studies a 10 mmol l −1 sucrose solution was used (Mita et al, 2014a). The method of application of the CS also differed.…”

Section: Introductionmentioning

confidence: 99%

“…The method of application of the CS also differed. The Takigami study ) used a perfusion system to deliver the CS, whilst we used a pipette to change the solutions (Mita et al, 2014a). With these differences in mind, we set out to compare conditioned taste aversion produced by the novel US with conditioned taste aversion produced using the KCl US.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Yerkes-Dodson law and appropriate stimuli for conditioned taste aversion in Lymnaea

Ito

Yamagishi

Takigami

et al. 2014

Self Cite

The pond snail Lymnaea stagnalis can learn conditioned taste aversion and then consolidate it into long-term memory (LTM). A high-voltage electric shock was used as the unconditioned stimulus, where we have previously used KCl. We varied the strength of both the conditioned and unconditioned stimuli to determine whether the so-called Yerkes-Dodson law prevailed. This is an empirical relationship between the state of arousal and LTM formation, showing that there is an optimal level of arousal leading to memory formation. However, too little or too much arousal results in poorer LTM. We found here that the most appropriate stimuli to use in taste aversion training in Lymnaea were a 10 mmol l −1 sucrose solution as the conditioned stimulus and a 3 s electric shock as the unconditioned stimulus.

“…Lymnaea stagnalis snails have been used extensively for the analysis of cellular and molecular mechanisms of locomotion (Syed and Winlow, 1991b;Pavlova, 2010;Longley and Peterman, 2013), feeding (Benjamin and Rose, 1979;Elliott and Benjamin, 1989;Kemenes and Elliott, 1994;Staras et al, 1998Staras et al, , 2003Alania et al, 2004;Vehovszky et al, 2005;Vavoulis et al, 2007;Chistopolsky and Dyakonova, 2012), respiration (Syed and Winlow, 1991a,b;Tsyganov et al, 2004;Bell et al, 2007), learning and memory (Kemenes et al, 1997(Kemenes et al, , 2002Kojima et al, 1997;Spencer et al, 1999;Staras et al, 1998;Jones et al, 2003;Sangha et al, 2003;Kemenes et al, 2006;Nikitin et al, 2008;Marra et al, 2013;Mita et al, 2014;Naskar et al, 2014), and decision making (Pirger et al, 2014;Crossley et al, 2016). There are also approaches that have been developed only in this organism, particularly the studies at the single-cell level of freshly isolated, not cultured, neurons (Dyakonova et al, 2009(Dyakonova et al, , 2015Dyakonova and Dyakonova, 2010), and experimental tests of an extracellular chemical microenvironment that has been demonstrated to play a prominent 'socializing' role in adjusting single-cell physiology to the network state (Dyakonova et al, 2015).…”

Section: Risky Decision Making By Snails In a Vital Situationmentioning

confidence: 99%

Previous motor activity affects transition from uncertainty to decision-making in snails

Korshunova

Vorontsov

Dyakonova

2016

One of the most widely accepted benefits of enhanced physical activity is an improvement in the symptoms of depression, including the facilitation of decision making. Up until now, these effects have been shown in rodents and humans only. Little is known about their evolutionary origin or biological basis, and the underlying cellular mechanisms also remain relatively elusive. Here, we demonstrate for the first time that preceding motor activity accelerates decision making in an invertebrate, the pond snail Lymnaea stagnalis. To investigate decision making in a novel environment, snails, which normally live in water, were placed on a flat dry surface to simulate the potentially threatening consequence of being in an arid environment. This stimulus initiated two distinct phases in snail behaviour: slow circular movements, followed by intense locomotion in a chosen direction. The first phase was prolonged when the test arena was symmetrically lit, compared with one with an apparent gradient of light. However, forced muscular locomotion for 2 h prior to the test promoted the transition from random circular motions to a directional crawl, accompanied by an increase in crawling speed but with no effect on the choice of direction. Intense locomotion for 2 h also produced a strong excitatory effect on the activity of serotonergic neurons in L. stagnalis. Our results suggest that the beneficial effects of physical exercise on cognitive performance in mammals might have deep roots in evolution, granting the opportunity to unravel the origins of such effects at the single-neuron and network levels.