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‐ HT 1 AR ) density in hippocampal tissue from patients with TLE ‐ HS . Methods We analyzed the hippocampal tissue of 34 patients with pharmacoresistant unilateral TLE ‐ HS . 5‐ HT 1 AR density was measured using semiquantitative western blotting. Results There was an association between higher density of 5‐ HT 1 AR and longer duration of epilepsy (Spearman correlation: P = 0.040; generalized linear model: P = 0.026). Conclusions This study demonstrated that hippocampal 5‐ HT 1 AR 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 .