Table 3.
Receptor subtype |
Process |
Epilepsy model |
Strategy |
Outcome |
References |
Ionotropic P2XRs | |||||
P2X7R | Status epilepticus | i.p. KA (25 mg/kg), i.p. picrotoxin (5 mg/kg), i.p. pilocarpine (150, 175, 200, 225, or 250 mg/kg) in mice (males) | i.c.v. OxATP (5 mM), A-438079 (10 μM), A740003 (10 μM) delivered over 1 week via osmotic mini-pump before seizure induction; P2X7R KO mice | Increased seizure susceptibility via P2X7R antagonism; P2X7R antagonisms did not affect seizures in KA and picrotoxin model. | (Kim and Kang, 2011) |
Status epilepticus | i.p. pilocarpine (380 mg/kg) in rats (males) | i.c.v. BZATP (5 mM), OxATP (5 mM), A-740003 (5 mM) and A-438079 (10 μM) via osmotic mini-pump | Reduced neurodegeneration via BzATP; increased neurodegeneration, reduced astroglial death and reduced infiltration of neutrophils mediated via P2X7R antagonism. | (Kim et al. 2009), (Kim et al. 2011), (Kim et al. 2010) | |
Status epilepticus | i.a. KA (3 μg/2 μl) in mice (males) | P2X7R agonists: i.c.v. BZATP (0.1 nmol); P2X7R antagonists: i.c.v. A438079 (1.75 nmol), i.c.v. BBG (1 pmol); i.c.v. P2X7R antibody (APR-008, 0.7 mg/mL); P2X7R KO mice | P2X7R agonist-increased seizure severity; P2X7R antagonists / P2X7R-targeting antibodies / P2X7R KO leads to seizure reduction and neuroprotection in hippocampus and cortex. | (Engel et al. 2012), ( Jimenez-Pacheco et al. 2013) | |
Status epilepticus | i.m. coriaria lactone (40 mg/kg) in rats (males) | Pre-treatment with P2X7R antagonists BBG (1, 5, 10 μg; i.c. v.), A438079 (10 μM, ic.v.) and A740003 (10 μM, i.c.v.) | P2X7R antagonism reduced inflammation, neuronal damage, astrogliosis and microgliosis, seizures and improved cognitive function. | (Huang et al. 2017) | |
Acute seizures (focal, generalized and generalized tonic-clonic) | Timed i.v. PTZ infusion test (1% PTZ 2 ml/min) in mice (males); MES-T; 6 Hz electroshock-induced seizures (0.2 ms square pulse at 6 Hz for 3 s) in mice (males) | i.p. BBG 150 mg/kg for i.v. PTZ and MES-T test and i.p. BBG 50 mg/kg for 6 Hz test | Reduced seizures during 6 Hz test (focal seizure) via BBG; no significant anticonvulsive effects of BBG in i.v. PTZ and MES-T test (generalized and generalized tonic-clonic seizures). | (Nieoczym et al. 2017) | |
Acute seizures (absence seizures) | WAG/Rij rats (males) (inbred strain of rats with genetic absence epilepsy) | i.c.v. BZATP (50 μg and 100 μg); i.c.v. A-438079 (20 μg and 40 μg) | No effects of P2X7R agonists or antagonists on spike-wave discharges (SWDs) | (Dogan et al. 2020) | |
Acute seizures / Epileptogenesis | MES-T (inusoidal pulses 4–14 mA, 50 Hz, 0.2 s duration) and s.c. PTZ-T (87 mg/kg) in mice (males); i.p. PTZ kindling (35 mg/ kg) in rats (males) for 25 days | JNJ-47965567 (15 or 30 mg/ kg),AFC-5128 (25 or 50 mg/ kg), BBG (50 mg/kg), transhinone (30 mg/kg), all drugs injected i.p. | No effects on acute seizures alone; reduced seizure severity in combination with carbamazepine; reduced kindling development and glial activation. | (Fischer et al. 2016) | |
Epileptogenesis | i.p. PTZ kindling (30 mg/kg) every second day for 27 days in rats (sex not specified) | BBG (15 and 30 mg/kg, i.p.) 30 min before PTZ injection | Reduced seizure score and improved motor performance and cognitive deficits. | (Soni et al. 2015) | |
Epileptogenesis | i.a. KA (3 μg/2 μl)-induced epilepsy in mice (males) | i.c.v. injection of antagomir-22 24 h before induction of SE | Increased P2X7R; increased seizure frequency during epilepsy, increased neuroinflammation. | (Jimenez-Mateos et al. 2015) | |
Epileptogenesis | i.p. pilocarpine (370 mg/kg,i.p.) in rats (males) | P2X7R antagonists AZ10606120 (3 μg/2 μl, i.c.v.) post-SE / BBG (50 mg/kg, i.p.) 1 injection per day for 4 days post-SE | Neuroprotection mediated via P2X7R antagonism post-SE; P2X7R antagonisms increased seizure number and seizure severity during epilepsy. | (Rozmer et al. 2017) | |
Epileptogenesis | i.p. pilocarpine (370 mg/kg) in rats (males) | P2X7R-targeting siRNA (i.c.v.) 6 h post-SE | P2X7R antagonisms mediated neuroprotection in hippocampus, reduced edema, reduced mortality following SE, delayed seizure onset and seizure numbers during chronic epilepsy. | (Amorim et al. 2017) | |
Epilepsy | Multiple low-dose i.p. KA-induced epilepsy in rats (males) (total KA = 22.2 ± 2.02 mg/kg) | JNJ-47965567 during 1 week via osmotic mini-pump (0.6 g/ kg/2 ml) | Decreased seizure severity without changes in total number of seizures, no change in inflammation. | (Amhaoul et al. 2016) | |
Epilepsy | i.a. KA (3 μg/2 μl)-induced-epilepsy in mice (males) | JNJ-47965567 (30 mg/kg, i.p.) twice daily for 5 days during epilepsy | Reduced seizure frequency during treatment and during washout-period; decreased inflammation (astrogliosis and microgliosis). | (Jimenez-Pacheco et al. 2016) | |
P2X3R | Epileptogenesis | i.p. PTZ (30 mg/kg) administered on alternate days for a maximum of up to 35 days to rats (males) | P2X3R antagonist i.c.v. delivery of P2X3 antagonist NF110 in 3 different doses (20 nM, 40 nM, and 60 nM) from day 1 until the end of the study (day 42) | P2X3R antagonisms improved impaired behavior, learning, memory, locomotion, motor activity, discrimination ability, neuronal damage, hippocampal inflammation, oxidative stress, and mitochondrial dysfunction | (Xia et al. 2018) |
P2X4R | Status epilepticus | i.p. KA (8–22 mg/kg) in mice (sex not specified) | P2X4R KO mice | Impaired microglial function; neuroprotection in hippocampus. | (Ulmann et al. 2013) |
Metabotropic P2Y receptors | |||||
P2Y 1 R | Status epilepticus | i.p. KA (10 mg/kg) in rats (males); intrahippocampal injection of quinolinic acid (1 μl at the rate of 0.2 μL/min) in rats (males) | One single injection of MRS2500 (nmol, i.c.v.) | P2Y1R antagonist-mediated neuroprotection; no impact on seizure severity. | (Simoes et al. 2018) |
Status epilepticus / Epileptogenesis / Epilepsy | i.a. KA (3 μg/2 μl) in mice; i.p. pilocarpine (340 mg/kg) in mice (males) | P2Y1R antagonist MRS2500 (1 nmol, i.c.v.) before and during SE, post-SE and during chronic epilepsy once daily for 5 days, P2Y1R KO mice; P2Y1R agonist MRS2365 (0.3 and 1 nmol, i.c. v.) before and during SE | P2Y1R KO mice: Increase in seizure severity during SE and neurodegeneration. Pre-treatment: P2Y1R agonist reduces seizure severity during SE and protects brain from damage; P2Y1R antagonism increases seizure severity and brain damage during SE. Treatment during SE: P2Y1R agonist increases seizure severity during SE; P2Y1R antagonism decreases seizure severity and brain damage (hippocampus and cortex). P2Y1R antagonism post-SE: Delay in epilepsy development. P2Y1R antagonism during epilepsy: Suppression of epileptic seizures. | (Alves et al. 2019); ( Alves et al. 2019) | |
P2Y 12 R | Status epilepticus | i.p. KA (18–22 mg/kg) or i.c.v. KA (0.12–0.18 μg)and KA in mice (males and females) | P2Y12R KO mice Increased seizure phenotype; reduced hippocampal microglial processes. | (Eyo et al. 2014) | |
Broad-spectrum targeting | |||||
Status epilepticus | i.a. KA (3 μg/2 μl) in mice (males) | ADP and UTP (P2Y agonists) (9 nmol i.c.v.) | ADP exacerbates seizure severity; UTP reduces seizure severity and neuronal death. | (Alves, Gomez-Villafuertes et al. 2017) | |
Epilepsy | Amygdala kindling in rats (males) (1 s, monophasic square-wave pulses) | Reactive Blue (P2YR antagonists, 20 μg) and PPADS (P2 antagonist, 10, 20, 30 μg) once daily i.c.v. | Reduced seizure severity. | (Sun et al. 2018) |
Abbreviations: ADP, Adenosine diphosphate; BBG, brilliant blue G; BzATP, 2’(3’)-O-(4-Benzoylbenzoyl)adenosine-5’-triphosphate; i.a., intraamygdala; i.m. intra-muscular; i.p., intraperitoneal; i.c.v., intracerebroventricular; i.v., intravenous; KA, Kainic acid; KO, Knock out; MES-T, Maximal electroshock seizure threshold test; PPADS, Pyridoxalphosphate-6-azophenyl-2’,4’-disulfonic; PTZ-T, Pentylenetetrazol seizure threshold test; SE, Status epilepticus; UDP, Uridine diphosphate; UTP, Uridine triphosphate.