P2Y1 receptor activation by photolysis of caged ATP enhances neuronal network activity in the developing olfactory bulb

Abstract

It has recently been shown that adenosine-5′-triphosphate (ATP) is released together with glutamate from sensory axons in the olfactory bulb, where it stimulates calcium signaling in glial cells, while responses in identified neurons to ATP have not been recorded in the olfactory bulb yet. We used photolysis of caged ATP to elicit a rapid rise in ATP and measured whole-cell current responses in mitral cells, the output neurons of the olfactory bulb, in acute mouse brain slices. Wide-field photolysis of caged ATP evoked an increase in synaptic inputs in mitral cells, indicating an ATP-dependent increase in network activity. The increase in synaptic activity was accompanied by calcium transients in the dendritic tuft of the mitral cell, as measured by confocal calcium imaging. The stimulating effect of ATP on the network activity could be mimicked by photo release of caged adenosine 5′-diphosphate, and was inhibited by the P2Y 1 receptor antagonist MRS 2179. Local photolysis of caged ATP in the glomerulus innervated by the dendritic tuft of the recorded mitral cell elicited currents similar to those evoked by wide-field illumination. The results indicate that activation of P2Y 1 receptors in the glomerulus can stimulate network activity in the olfactory bulb.

Adenosine A1 receptor activates background potassium channels and modulates information processing in olfactory bulb mitral cells

“…Olfactory bulbs were dissected and horizontal brain slices were prepared as described before (Fischer et al . ). Olfactory bulbs were quickly transferred into a chilled slicing artificial cerebrospinal fluid (ACSF) that contained (in m m ): NaCl, 83; NaHCO 3 , 26.2; NaH 2 PO 4 , 1; KCl, 2.5; sucrose, 70; d ‐glucose, 20; CaCl 2 , 0.5; MgSO 4 , 2.5.…”

“…ATP excites mitral cells via P2Y 1 receptors (Fischer et al . ), is then degraded to adenosine and elicits calcium transients in astrocytes expressing A 2A receptors, emphasizing a physiological relevance of adenosine in this brain area (Doengi et al . ).…”

Dopamine-induced calcium signaling in olfactory bulb astrocytes

“…According to the local laws, an additional ethical approval for animal experiments in the current study was not required. Olfactory bulb slices were prepared as described before 60 . Slices were quickly transferred into a chilled artificial cerebrospinal fluid (ACSF, see below).…”

Purinergic signalling during development and ageing

“…ATP and adenosine mediate responses of sympathetic preganglionic neurons in a neonatal rat brain stem-spinal cord preparation. Activation of P2Y 1 receptors in the glomerulus stimulated neuronal network activity in the developing olfactory bulb [184].…”