Spatial memory in vertebrates requires brain regions homologous to the mammalian hippocampus. Between vertebrate clades, however, these regions are anatomically distinct and appear to produce different spatial patterns of neural activity. We asked whether hippocampal activity is fundamentally different even between distant vertebrates that share a strong dependence on spatial memory. We studied tufted titmice, food-caching birds capable of remembering many concealed food locations. We found mammalian-like neural activity in the titmouse hippocampus, including sharp-wave ripples and anatomically organized place cells. In a non–food-caching bird species, spatial firing was less informative and was exhibited by fewer neurons. These findings suggest that hippocampal circuit mechanisms are similar between birds and mammals, but that the resulting patterns of activity may vary quantitatively with species-specific ethological needs.

脊椎动物的空间记忆需要与哺乳动物海马体同源的大脑区域。然而，在脊椎动物进化枝之间，这些区域在解剖学上是不同的，并且似乎产生不同的神经活动空间模式。我们询问即使在对空间记忆具有强烈依赖性的远距离脊椎动物之间，海马活动是否也存在根本差异。我们研究了簇状山雀，能够记住许多隐藏食物位置的食物缓存鸟类。我们在山雀海马体中发现了类似哺乳动物的神经活动，包括锐波涟漪和解剖学组织的位置细胞。在非食物缓存鸟类中，空间放电提供的信息较少，并且表现出较少的神经元。这些发现表明鸟类和哺乳动物之间的海马回路机制相似，