Browsing by Author "Correia, Alexandra M."
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- Neuromuscular transmission modulation by adenosine upon agingPublication . Pousinha, Paula A.; Correia, Alexandra M.; Sebastião, Ana M; Ribeiro, Joaquim A.In infant rats adenosine A2A receptor-mediated modulation of neuromuscular transmission predominates over A1 receptor-mediated neuromodulation.We investigated whether aging affects this A2A/A1 receptor balance. Evoked (EPPs) and miniature end plate potentials(MEPPs) were recorded from single fibers of (weeks-old) infant (3– 4), young adult (12–16), older (36 –38),and aged (80 –90) male rat-diaphragm. The non A1/A2A selective agonist, 2-chloroadenosine (CADO; 30 nM) and the adenosine kinase inhibitor, iodotubericidin (ITU; 10 M) increased mean amplitude and quantal content of EPPs in infant, young adult, and older adult rats, but not in aged rats. The facilitatory effects were prevented by the A2A receptor antagonist,ZM241385 (50 nM) and mimicked by the A2A receptor agonist,CGS21680 (10 nM). The A1 receptor agonist, 6-cyclopentyladenosine (CPA; 100 nM), decreased EPPs amplitude in all age groups. It is concluded that aging differently influences adenosine A1 receptor and A2A receptor-mediated presynaptic modulation of neuromuscular transmission, so that the facilitatory influence decreases upon aging, whereas the inhibitory influence remains unchanged in aged animals. The reduction of adenosine A2A receptors upon aging may contribute to the age-related changes in neuromuscular function.
- Revisiting Biodiversity and Ecosystem Functioning through the Lens of Complex Adaptive SystemsPublication . Correia, Alexandra M.; Lopes, Luís FilipeUnderstanding the relationship between biodiversity and ecosystem functioning (BEF) is essential to comprehend the impacts of biodiversity changes on ecosystem functioning. This knowledge helps to detect and anticipate significant trends in global biodiversity loss and the homogenization of biota worldwide to prevent them. Species act together with climate, resource availability, and disturbance regimes to modulate ecological processes defining ecosystems’ complexity and their dynamic adaptation to variability. In this article, we revisit the BEF paradigm by addressing current knowledge of how biodiversity connects to ecosystem functioning across scales in the context of complex adaptive systems (CAS). We focus on ecosystem processes that lead to the emergence of the BEF relationship, considering ecosystem functioning as a macroscopic emergent property. Specifically, this work integrates the knowledge of the processes that connect biodiversity to ecosystem functioning. It addresses how biodiversity supports ecosystem multifunctionality across scales, resulting in the persistence of CAS in a rapidly changing world. We present a framework for ecological management considering the BEF relationship within the scope of CAS. The CAS standpoint brings new insights into the BEF field and its relevance for future ecological conservation of the Earth’s life support.