https://www.selleckchem.com/products/fdi-6.html Age and duration of the UDT have not influenced the VAS score. Although the UDT has resulted in 40% of the pediatric patients in our study expressing discomfort or pain, it is a well-tolerated test. The variables that have influenced on pain perception were patient's anxiety prior to UDT, a sensory-motor alteration located in the lumbosacral metameres, difficult bladder catheterization and the appearance of pain during bladder filling. Although the UDT has resulted in 40% of the pediatric patients in our study expressing discomfort or pain, it is a well-tolerated test. The variables that have influenced on pain perception were patient's anxiety prior to UDT, a sensory-motor alteration located in the lumbosacral metameres, difficult bladder catheterization and the appearance of pain during bladder filling.The survival of all species requires appropriate behavioral responses to environmental challenges. Learning is one of the key processes to acquire information about the environment and adapt to changing and uncertain conditions. Learning has long been acknowledged in animals from invertebrates to vertebrates but remains a subject of debate in non-animal systems such a plants and single cell organisms. In this review I will attempt to answer the following question are single cell organisms capable of learning? I will first briefly discuss the concept of learning and argue that the ability to acquire and store information through learning is pervasive and may be found in single cell organisms. Second, by focusing on habituation, the simplest form of learning, I will review a series of experiments showing that single cell organisms such as slime molds and ciliates display habituation and follow most of the criteria adopted by neuroscientists to define habituation. Then I will discuss disputed evidence suggesting that single cell organisms might also undergo more sophisticated forms of learning such as associative learning