Operant conditioning prevents cell death in the adult rat dentate gyrus

Thousands of new neurons are produced each day in the dentate gyrus of the adult mammalian hippocampus. However, the majority of those cells die within weeks of their birth. The most effective way to prevent this cell death is through effortful and successful learning. Myriad studies have revealed that classical conditioning and spatial learning can prevent this cell death. However, little research has examined whether acquisition of an operant conditioning task with an appetitive reward also increases the number of surviving cells. Therefore, the current study was conducted to determine whether conditioning with an operant procedure would prevent the death of adult-born hippocampal cells. Adult male rats were trained with 50 trials of an operant discrimination procedure per day for four consecutive days. In order to motivate animals to perform the task, they were food restricted prior to conditioning, and food pellets were used as an appetitive reward during training. Additional control animals were food restricted but not trained, or not food restricted and not trained. In order to ensure that exposure to food reward pellets did not alter cell survival, all animals received equal exposure to the food pellets. Stereological analysis conducted approximately two weeks after training revealed that food restriction decreased the number of surviving cells in the dentate gyrus (p < .05). However, training with the operant task prevented that decrease (p < .05). Together, these results indicate that food restriction decreased the number of surviving cells in the dentate gyrus, and training with an operant procedure was sufficient to attenuate that decrease. (PsycINFO Database Record (c) 2019 APA, all rights reserved).