Hyperthermia‐induced seizures alter adenosine A 1 and A 2A receptors and 5′‐nucleotidase activity in rat cerebral cortex

Febrile seizure is one of the most common convulsive disorders in children. The neuromodulator adenosine exerts anticonvulsant actions through binding adenosine receptors. Here, the impact of hyperthermia‐induced seizures on adenosine A 1 and A 2A receptors and 5′‐nucleotidase activity has been studied at different periods in the cerebral cortical area by using radioligand binding, real‐time PCR , and 5′‐nucleotidase activity assays. Hyperthermic seizures were induced in 13‐day‐old rats using a warmed air stream from a hair dryer. Neonates exhibited rearing and falling over associated with hindlimb clonus seizures (stage 5 on Racine scale criteria) after hyperthermic induction. A significant increase in A 1 receptor density was observed using [ 3 H] DPCPX as radioligand, and mRNA coding A 1 was observed 48 h after hyperthermia‐induced seizures. In contrast, a significant decrease in A 2A receptor density was detected, using [ 3 H]ZM241385 as radioligand, 48 h after hyperthermia‐evoked convulsions. These short‐term changes in A 1 and A 2A receptors were also accompanied by a loss of 5′‐nucleotidase activity. No significant variations either in A 1 or A 2A receptor density or 5′‐nucleotidase were observed 5 and 20 days after hyperthermic seizures. Taken together, both regulation of A 1 and A 2A receptors and loss of 5′‐nucleotidase in the cerebral cortex suggest the existence of a neuroprotective mechanism against seizures. image Febrile seizure is one of the most common convulsive disorders in children. The consequences of hyperthermia‐induced seizures (animal model of febrile seizures) on adenosine A 1 and A 2A receptors and 5'‐nucleotidase activity have been studied at different periods in cerebral cortical area. A significant increase in A 1 receptor density and mRNA coding A 1 was observed 48 h after hyperthermia‐induced seizures. In contrast, a significant decrease in A 2A receptor density and 5'‐nucleotidase activity was detected 48 h after convulsions evoked by hyperthermia. These changes suggest the possible existence of a neuroprotective mechanism against seizures.