title: Increased neurokinin-1 receptor availability in temporal lobe epilepsy: a positron emission tomography study using [(11)C]GR205171.
abstract: OBJECTIVE
  Activation of the neurokinin-1 (NK1) receptor by neuropeptide substance P (SP) induces and maintains epileptic activity in various experimental models of epilepsy. The primary objective of this study was to investigate whether neurobiological changes linked to NK1-SP receptor system are associated with hyperexcitability in patients with temporal lobe epilepsy (TLE). A secondary objective was to investigate the relationship between seizure frequency and NK1 receptor availability.
  
  
  METHODS
  A positron emission tomography study was conducted with the selective NK1 receptor antagonist [(11)C]GR205171 in nine patients with TLE and 18 healthy control participants. Parametric PET images were generated using the Patlak graphical method, with cerebellum as reference region. Data analyses including group comparisons were performed using statistical parametric mapping.
  
  
  RESULTS
  Patients with TLE showed increased NK1 receptor availability in both hemispheres with the most pronounced increase in anterior cingulate gyrus ipsilateral to seizure onset. A positive correlation between NK1 receptor availability and seizure frequency was observed in the medial temporal lobe and in the lentiform nucleus ipsilateral to the seizure onset.
  
  
  CONCLUSIONS
  Our results suggest that there is an intrinsic network using the NK1-SP receptor system for synaptic transmission and epileptiform activity in TLE.
authors.affiliation: Department of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden. Torsten.Danfors@neuro.uu.se
authors.forename: Torsten
authors.initials: T
authors.lastname: Danfors
authors.forename: Fredrik
authors.initials: F
authors.lastname: Åhs
authors.forename: Lieuwe
authors.initials: L
authors.lastname: Appel
authors.forename: Clas
authors.initials: C
authors.lastname: Linnman
authors.forename: Mats
authors.initials: M
authors.lastname: Fredrikson
authors.forename: Tomas
authors.initials: T
authors.lastname: Furmark
authors.forename: Eva
authors.initials: E
authors.lastname: Kumlien
mesh_terms: D000328:Adult; D002250:Carbon Radioisotopes; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D064729:Neurokinin-1 Receptor Antagonists; D010880:Piperidines; D049268:Positron-Emission Tomography / Q000379:methods*; D018040:Receptors, Neurokinin-1 / Q000378:metabolism*; D012720:Severity of Illness Index; D013373:Substance P / Q000378:metabolism; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism; D013777:Tetrazoles; D055815:Young Adult
chemical_list: D002250:Carbon Radioisotopes; D064729:Neurokinin-1 Receptor Antagonists; D010880:Piperidines; D018040:Receptors, Neurokinin-1; D013777:Tetrazoles; D013373:Substance P; C103207:vofopitant