Plasticity in the hippocampal formation of shorebirds during the wintering period: stereological analysis of parvalbumin neurons in Actitis macularius

• Autor(a) principal: Guerreiro, Luma Cristina Ferreira
• Data de Publicação: 2021
• Outros Autores: Henrique, Ediely Pereira, Rosa, João Batista da Silva, Pereira, Patrick Douglas Corrêa, Abreu, Cintya Castro de, Fernandes, Taiany Nogueira, Magalhães, Nara Gyzely de Morais, Silva, Anderson de Jesus Falcão da, Costa, Emanuel Ramos da, Diniz, Cristovam Guerreiro, Diniz, Cristovam Wanderley Picanço, Diniz, Daniel Guerreiro
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Digital do Instituto Evandro Chagas (Patuá)
• Texto Completo: https://patua.iec.gov.br/handle/iec/4390
• topic: Aves / anatomia & histologia; Migração Animal; Voo Animal; Sistema Nervoso / anatomia & histologia; Área Pré-Tectal; Parvalbuminas / análise; Hipocampo

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.