In classical neuroscience, Dale ́s principle postulates that neuronal identity is conferred by the specific neurotransmitter that it releases. However, the brain might be more tractable to specific situations regardless of specific specialisation which may contradict this principle. Hence, this constrained approach of how we perceive and study the nervous system must be revisited and revised, specifically by studying the dopaminergic system. We presume a relatively flexible change in the dopaminergic system due to neuronal activity or environmental changes. While the parallel between the reward system of mammals and insects is generally well accepted, herein, we extend the idea that the insect nervous system might also possess incredible plasticity, similar to the mammalian system. In this review, we critically evaluate the available information about the reward system in vertebrates and invertebrates, emphasising the dopaminergic neuronal plasticity, a challenge to the classical Dale's principle. Thus, neurotransmitter switching significantly disrupts the static idea of neural network organisation and suggests greater possibilities for a dynamic response to the current life context of organisms.

• MeSH
• dopamin MeSH
• dopaminergní neurony fyziologie   MeSH
• Drosophila melanogaster fyziologie   MeSH
• Drosophila * fyziologie   MeSH
• houbová tělesa * fyziologie   MeSH
• lidé MeSH
• neurotransmiterové látky fyziologie   MeSH
• savci MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

The fruit fly Drosophila melanogaster brain is the most extensively investigated model of a reward system in insects. Drosophila can discriminate between rewarding and punishing environmental stimuli and consequently undergo associative learning. Functional models, especially those modelling mushroom bodies, are constantly being developed using newly discovered information, adding to the complexity of creating a simple model of the reward system. This review aims to clarify whether its reward system also includes a hedonic component. Neurochemical systems that mediate the 'wanting' component of reward in the Drosophila brain are well documented, however, the systems that mediate the pleasure component of reward in mammals, including those involving the endogenous opioid and endocannabinoid systems, are unlikely to be present in insects. The mushroom body components exhibit differential developmental age and different functional processes. We propose a hypothetical hierarchy of the levels of reinforcement processing in response to particular stimuli, and the parallel processes that take place concurrently. The possible presence of activity-silencing and meta-satiety inducing levels in Drosophila should be further investigated.

• MeSH
• Drosophila melanogaster * MeSH
• Drosophila * MeSH
• houbová tělesa MeSH
• odměna MeSH
• posilování (psychologie) MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH