NMDA Receptor Activation and Ca/PKC Signaling in Nicotine-Induced GABA Transport Shift in Embryonic Chick Retina.

Nicotinic receptors are present in the retina of different vertebrates, and in the chick retina, it is present during early development throughout to post-hatching. These receptors are activated by nicotine, an alkaloid with addictive and neurotransmitter release modulation properties, such as GABA signaling. Here we evaluated the mechanisms of nicotine signaling in the avian retina during the development of neuron-glia cells at a stage where synapses are peaking.

Caffeine regulates GABA transport via AR blockade and cAMP signaling.

Caffeine is the most consumed psychostimulant drug in the world, acting as a non-selective antagonist of adenosine receptors AR and AR, which are widely expressed in retinal layers. We have previously shown that caffeine, when administered acutely, acts on AR to potentiate the NMDA receptor-induced GABA release. Now we asked if long-term caffeine exposure also modifies GABA uptake in the avian retina and which mechanisms are involved in this process.