| Texto completo | |
| Autor(es): |
Bezerra, Thiago Ohno
;
Roque, Antonio C.
Número total de Autores: 2
|
| Tipo de documento: | Artigo Científico |
| Fonte: | PLOS COMPUTATIONAL BIOLOGY; v. 20, n. 12, p. 26-pg., 2024-12-01. |
| Resumo | |
Astrocytes respond to neurotransmitters by increasing their intracellular Ca2+ concentration (Ca2+ signals). While glutamate released by neurons trigger Ca2+ signals through IP3- and glutamate transporter-dependent mechanisms, dopamine released in distant sites activates astrocytes via dopaminergic receptors. However, little is known about the modulatory effects of dopamine on glutamate-evoked astrocytic activity. To investigate this question, we developed multi-compartment, conductance-based astrocyte models with three distinct morphologies: unipolar; bipolar; and bifurcated-terminal. Glutamate induced localized responses, while dopamine activated all compartments. In the unipolar model, global dopaminergic stimulation reduced the threshold frequency of glutamatergic stimulation required to activate Ca2+ signals. Phase-plane analysis of a simplified version of this model revealed that Ca2+ signals are influenced by compartment radius and neurotransmitter type. Morphology significantly influenced glutamate-dopamine interactions. In the bipolar model, glutamatergic stimulation in one process minimally affected the other. Conversely, in the bifurcated-terminal model, where a single process bifurcates into two secondary processes, high-frequency glutamatergic stimulation in one secondary process evoked Ca2+ signals in the other. Dopamine further facilitated this latter cross-process interaction by lowering the glutamatergic stimulation frequency needed to elicit Ca2+ signals in the adjacent secondary process. These findings suggest that dopamine enhances the initiation and propagation of glutamate-evoked Ca2+ signals, with the extent of propagation depending on astrocytic morphology and the spatial distribution of glutamatergic inputs. (AU) | |
| Processo FAPESP: | 13/07699-0 - Centro de Pesquisa, Inovação e Difusão em Neuromatemática - NeuroMat |
| Beneficiário: | Oswaldo Baffa Filho |
| Modalidade de apoio: | Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs |
| Processo FAPESP: | 21/12832-7 - Impacto da Transmissão Dopaminérgica em uma Rede Neural Acompanhada por Astrócitos para a Simulação da Memória de Trabalho |
| Beneficiário: | Thiago Takechi Ohno Bezerra |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |