5‐hydroxytryptamine1A receptor density in the hippocampus of patients with temporal lobe epilepsy is associated with disease duration

BACKGROUND AND PURPOSE: To date, no study has evaluated the association between serotonin receptor density and clinical variables in patients with temporal lobe epilepsy caused by hippocampal sclerosis (TLE-HS) using hippocampal tissue. We evaluated 5-hydroxytryptamine1A receptor (5-HT1AR) density in hippocampal tissue from patients with TLE-HS. METHODS: We analyzed the hippocampal tissue of 34 patients with pharmacoresistant unilateral TLE-HS. 5-HT1AR density was measured using semiquantitative western blotting. RESULTS: There was an association between higher density of 5-HT1AR and longer duration of epilepsy (Spearman correlation: P = 0.040; generalized linear model: P = 0.026). CONCLUSIONS: This study demonstrated that hippocampal 5-HT1AR density is associated with epilepsy duration in patients with TLE-HS. The authors postulate that this may represent a potential regulatory enhancement of endogenous serotonergic neurotransmission in response to prolonged and enduring epileptiform activity in the hippocampal tissue of patients with pharmacoresistant TLE-HS.