Within-species variation in the number of neurons, other brain cells and their allocation to different brain parts is poorly studied. Here, we assess these numbers in a squamate reptile, the Madagascar ground gecko (Paroedura picta). We examined adults from two captive populations and three age groups within one population. Even though reptiles exhibit extensive adult neurogenesis, intrapopulation variation in the number of neurons is similar to that in mice. However, the two populations differed significantly in most measures, highlighting the fact that using only one population can underestimate within-species variation. There is a substantial increase in the number of neurons and decrease in neuronal density in adult geckos relative to hatchlings and an increase in the number of neurons in the telencephalon in fully grown adults relative to sexually mature young adults. This finding implies that adult neurogenesis does not only replace worn out but also adds new telencephalic neurons in reptiles during adulthood. This markedly contrasts with the situation in mammals, where the number of cortical neurons declines with age.

对神经元、其他脑细胞数量及其在不同大脑部位分配的物种内变异的研究很少。在这里，我们评估了有鳞爬行动物马达加斯加地面壁虎（Paroedura picta）。我们检查了来自两个圈养种群和一个种群中三个年龄组的成年人。尽管爬行动物表现出广泛的成年神经发生，但神经元数量的种群内变化与小鼠相似。然而，这两个种群在大多数测量中存在显着差异，突出了仅使用一个种群会低估种内变异的事实。与幼龟相比，成年壁虎的神经元数量显着增加，神经元密度降低，成年壁虎的端脑神经元数量相对于性成熟的年轻成人增加。这一发现意味着成年神经发生不仅取代了磨损的爬行动物，而且还在成年期为爬行动物增加了新的端脑神经元。这与哺乳动物的情况形成鲜明对比，