The number of parvalbumin neurons can be modified by social, multisensory, and cognitive stimuli in both mammals and birds, but nothing is known about their plasticity in long-distance migratory shorebirds. Here, in the spotted sandpiper (Actitis macularius), we investigated the plasticity of parvalbumin neurons of two brain areas during this species’ wintering period at a lower latitude. We compared individuals in a nonmigratory rest period (November–January) and premigration (May–July) period. We used parvalbumin as a marker for counting a subpopulation of inhibitory neurons in the hippocampal formation (HF), with the magnocellular nucleus of the tectal isthmus (IMC) as a control area. Because the HF is involved in learning and memory and social interaction and the IMC is essential for control of head, neck, and eye movements, we hypothesized that parvalbumin neurons would increase in the HF and remain unchanged in the IMC. We used an optical fractionator to estimate cell numbers. Compared with the nonmigratory rest birds, parvalbumin neuron count estimates in the premigration birds increased significantly in the HF but remained unchanged in IMC. We suggest that the greater number of parvalbuminergic neurons in the HF of A. macularius in the premigration period represents adaptive circuitry changes involved in the migration back to reproductive niches in the northern hemisphere.

在哺乳动物和鸟类中，小白蛋白神经元的数量可以通过社交、多感觉和认知刺激来改变，但对于它们在长距离迁徙滨鸟中的可塑性却一无所知。在这里，在斑点鹬（Actis macularius)，我们研究了该物种在低纬度越冬期间两个大脑区域的小白蛋白神经元的可塑性。我们比较了非迁移休息期（11 月至 1 月）和迁移前（5 月至 7 月）期间的个体。我们使用小白蛋白作为计数海马形成 (HF) 中抑制性神经元亚群的标记，以顶盖峡部 (IMC) 的大细胞核作为控制区域。因为 HF 涉及学习、记忆和社交互动，而 IMC 对于控制头部、颈部和眼球运动至关重要，我们假设小白蛋白神经元会在 HF 中增加，而在 IMC 中保持不变。我们使用光学分馏器来估计细胞数。与非迁徙性休养鸟相比，前候鸟中的小白蛋白神经元计数估计值在 HF 中显着增加，但在 IMC 中保持不变。我们建议在 HF 中更多的小白蛋白能神经元A. macularius在迁徙前阶段代表了迁徙回北半球生殖生态位所涉及的适应性电路变化。