A1 and A2 adenosine receptors modulate acetylcholine release from brain slices

Transducing system operated by adenosine A2A receptors to facilitate acetylcholine release in the rat hippocampus

“…In fact, the presence of adenosine A 2A receptors has been observed in cholinergic nerve terminals of the striatum (Brown et al, 1990), in motor nerve terminals (Correia-de-Sá and Ribeiro, 1994) and in Torpedo electric organ nerve terminals (Satoh et al, 1997), although in the cerebral cortex the picture is less clear (cf. Broad and Fredholm, 1996;Phillis et al, 1993;Spignoli et al, 1984). As we now observed in the hippocampus, the facilitation of the evoked release of acetylcholine by adenosine A 2A receptors in all these systems is small in amplitude (lower than 30%), appears to be larger in amplitude in intact preparations than in purified nerve terminals (see Cunha et al, 1994a;Jin and Fredholm, 1997), but always involves the activation of the cAMP/protein kinase A pathway.…”

The adenosine receptor‐mediated inhibition of noradrenaline release possibly involves a N‐protein and is increased by α2‐autoreceptor blockade

“…of acetylcholine (Harms et al, 1979;Pedata et al, 1983;Spignoli et al, 1984;Jackisch et al, 1984b), noradrenaline (Harms et al, 1978;Fredholm et al, 1983;Jackisch et al, 1985a) and 5-hydroxytryptamine (Harms et al, 1979;Feuerstein et al, 1985) from CNS tissue slices is inhibited by adenosine. The adenosine receptors which inhibit the stimulation-evoked release of these neurotransmitters in the rabbit hippocampus have been characterized as A,-receptors (Jackisch et al, 1984b;1985a;Feuerstein et al, 1985).…”

Anxiolytic activity of adenosine receptor activation in mice

“…The presynaptic sites may be a combination of Al and A2 receptors, activation of the former generally inhibiting the release of neurotransmitters such as glutamate (Clark & Dar, 1989;Corradetti et al, 1984;Fastbom & Fredholm, 1985;Prince & Stevens, 1992), acetylcholine (Spignoli et al, 1984), dopamine (Michaelis et al, 1979;Zetterstrom & Fillenz, 1990), 5-hydroxytryptamine (Feuerstein et al, 1985) and noradrenaline (Jonzon & Fredholm, 1984). The A2 receptors tend to increase the release of some of these transmitters (Spignoli et al, 1984;Correiadesa et al, 1991;Kirkpatrick & Richardson, 1993).…”

“…The presynaptic sites may be a combination of Al and A2 receptors, activation of the former generally inhibiting the release of neurotransmitters such as glutamate (Clark & Dar, 1989;Corradetti et al, 1984;Fastbom & Fredholm, 1985;Prince & Stevens, 1992), acetylcholine (Spignoli et al, 1984), dopamine (Michaelis et al, 1979;Zetterstrom & Fillenz, 1990), 5-hydroxytryptamine (Feuerstein et al, 1985) and noradrenaline (Jonzon & Fredholm, 1984). The A2 receptors tend to increase the release of some of these transmitters (Spignoli et al, 1984;Correiadesa et al, 1991;Kirkpatrick & Richardson, 1993). Postsynaptically, adenosine and its analogues can increase potassium (Haas & Greene, 1984;Trussel & Jackson, 1985) and chloride conductances (Mager et al, 1990;Akhondzadeh & Stone, 1994) and can modulate neuronal sensitivity to transmitters such as acetylcholine (Brooks & Stone, 1988) and dopamine (Ferre et al, 1991).…”