In contrast, the proportion of astrocytes generated from new-born cells was increased after auditory fear conditioning. Chronic treatment with FLX ameliorated the changes in adult neurogenesis induced by auditory fear conditioning and led to an improvement in the long-lasting auditory fear memory. The main findings of the present study were that the persistent auditory fear memory induced by fear conditioning led to decrease the survival and an alteration in the differentiation pattern of newborn cells in the amygdala. Chronic treatment with FLX LY294002 before auditory fear conditioning partially rescued the impairment of the amygdaloid neurogenesis and suppressed long-lasting auditory fear memory in rats. Fear conditioning is a widely used as a model of PTSD. Previous studies have shown that fear learning and traumatic stress reduced hippocampal neurogenesis. Hippocampal neurogenesis is involved in learning and maintainence of contextual fear memory. In studying of the neurogenesis in the amygdala, only a few concerned stress and amygdaloid adult-born cells were reported. Resently, Lieberwirth et al. found that the stressful social isolation reduced amygdaloid cell survival and neuronal differentiation in adult prairie voles. Extending this finding, our data showed that auditory fear conditioning also significantly decreased cell survival and neuronal differentiation in the rat amygdala. Furthermore, our data showed that the alteration of neurogenesis was accompanied by enhanced gliogenesis because a higher proportion of astrocytes developed from the BrdU-positive cells. Similar alterations wese observed in the hippocampus, but the alteration was transient lasting about two weeks. The different effects of auditory fear conditioning on cell differentiation in the hippocampus and amygdala might indicate their different functions in auditory fear memory. How the observed changes in the differentiation of newly generated cells would affect the functions of the amygdala remains largely unknown. Adult-born neurons in the hippocampus are involved in certain types of memory, new neurons in the olfactory bulb contribute to olfactory discrimination learning, and new neurons in the hypothalamus are involved in energy balance. The amygdala is an important structure for the acquisition and storage of fear memory. Thus, it is likely that amygdaloid adult-generated neurons are involved in memory processes. The decrease in the number of mature neurons and the increase in the number of astrocytes in the amygdala after auditory fear conditioning might relate to structural plasticity and lead to the persisitence of auditory fear memory. Conversely, enhancement of the adult neurogenesis by FLX treatment might lead the animal to better adapt the situation, leading to the suppression of the maintenance of the fear memory. FLX treatment is known to increase adult neurogenesis in the rodent hippocampus.