LH-RH in picomole concentrations evokes excitation and inhibition of rat arcuate neurones in vitro.
A medial sagittal brain slice was developed, which enabled electrophysiological recording from spontaneously active neurones adjacent to the infundibular recess of the rat arcuate nucleus. Luteinizing hormone-releasing hormone (LH-RH) (10 nM-10 pM) significantly altered the frequency of 21 out of 31 units tested, exciting 14 and inhibiting 7 others. The excitatory responses were often not maintained during the exposure to LH-RH but either returned to pre-exposure frequency or displayed an inhibition of discharge. A neural model incorporating recurrent inhibition of LH-RH-excited neurones is proposed to explain these responses, thought to be endogenously evoked by collateral innervation of the arcuate nucleus by medial preoptic neurones projecting to the median eminence.
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000187:drug effects / Q000502:physiology*; D004553:Electric Conductivity; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D008832:Microchemistry; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains
D007987:Gonadotropin-Releasing Hormone