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Updated: Oct 16, 2026

Preparation of Acute Hippocampal Slices from Rats and Transgenic Mice for the Study of Synaptic Alterations during Aging and Amyloid Pathology
Published on: March 23, 2011
Tonic adenosine neuromodulation is preserved in motor nerve endings of aged rats
M F Pereira1, R A Cunha, J A Ribeiro
1Laboratory of Neurosciences, Faculty of Medicine, University of Lisbon, Av. Prof. Egas Moniz, Lisbon, Portugal.
Abstract:
Neuromuscular transmission is decreased in aged subject. Since endogenous adenosine is a potent neuromodulator at motor nerve endings, either inhibiting via A(1) receptors or facilitating via A(2A) receptors acetylcholine release, we now investigated if the tonic effect of endogenous adenosine was modified at phrenic nerve endings of aged rats. The A(2A) receptor antagonist (ZM241385, 50 nM) inhibited (77 +/- 9%) and the A(1) receptor antagonist (DPCPX, 50 nM) facilitated (74 +/- 13%) acetylcholine release from young adult (6 weeks old) rat preparations, indicating a simultaneous tonic activation of A(2A) and A(1) receptors. Tonic modulation by adenosine was unaltered in aged (24 months old) rats, since ZM241385 (50 nM) inhibited (73 +/- 8%) and DPCPX (50 nM) facilitated (91 +/- 20%) acetylcholine release in aged animals similarly to young rats. This indicates that, in contrast to the central nervous system where adenosine neuromodulation is modified in aged animals, the control by adenosine of phrenic nerve function is preserved in aged animals.
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