title: NK1 receptors antagonism of dorsal hippocampus counteract the anxiogenic-like effects induced by pilocarpine in non-convulsive Wistar rats.
abstract: Recent evidence supports a role for the substance P (SP) in the control of anxiety and epilepsy disorders. Aversive stimuli alter SP levels and SP immunoreactivity in limbic regions, suggesting that changes in SP-NK1 receptor signaling may modulate the neuronal excitability involved in seizures and anxiogenesis. The involvement of NK1 receptors of the dorsal hippocampus and lateral septum in the anxiogenic-like effects induced by a single injection of pilocarpine (PILO) was examined in non-convulsive rats evaluated in the elevated plus-maze (EPM). Male Wistar rats were systemically injected with methyl-scopolamine (1mg/kg) followed 30 min later by saline or PILO (350 mg/kg) and only rats that did not present status epilepticus were used. One month later, vehicle or FK888 (100 pmol) - an NK1 receptor antagonist - were infused in the dorsal hippocampus or the lateral septum of the rats and then behaviorally evaluated in the EPM. Previous treatment with PILO decreased the time spent in and the frequency of entries in the open arms of the EPM, besides altering risk-assessment behaviors such as the number of unprotected head-dipping, protected stretch-attend postures and the frequency of open-arms end activity, showing thus a long-lasting anxiogenic-like profile. FK888 did not show any effect per se but inhibited the anxiogenic responses induced by PILO when injected into the dorsal hippocampus, but not into the lateral septum. Our data suggest that SP-NK1 receptor signaling of the dorsal hippocampus is involved in the anxiogenic-like profile induced by PILO in rats evaluated in the EPM test.
authors: Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, PE 50670-901, Brazil.
authors: Filipe Silveira
authors: FS
authors: Duarte
authors: Postgraduate Program in Medical Science, Center of Health Sciences, University Hospital, Federal University of Santa Catarina, Florianópolis, SC 88040-970, Brazil; Department of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, SC 88049-900, Brazil.
authors: Alexandre Ademar
authors: AA
authors: Hoeller
authors: Institute of Biological Sciences and Health, Federal University of Alagoas, Maceió, AL 57020-720, Brazil.
authors: Marcelo
authors: M
authors: Duzzioni
authors: Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal, RN 59072-970, Brazil.
authors: Elaine Cristina
authors: EC
authors: Gavioli
authors: Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil.
authors: Newton Sabino
authors: NS
authors: Canteras
authors: Department of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, SC 88049-900, Brazil. Electronic address: thereza.lima@ufsc.br.
authors: Thereza Christina Monteiro
authors: TC
authors: De Lima
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000927:Anticonvulsants / Q000627:therapeutic use*; D004151:Dipeptides / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D007211:Indoles / Q000627:therapeutic use*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D018721:Muscarinic Agonists / Q000633:toxicity; D019832:N-Methylscopolamine / Q000633:toxicity; D010276:Parasympatholytics / Q000633:toxicity; D010862:Pilocarpine / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar; D013226:Status Epilepticus / Q000139:chemically induced / Q000188:drug therapy*
chemical_list: D000927:Anticonvulsants; D004151:Dipeptides; D007211:Indoles; D018721:Muscarinic Agonists; D010276:Parasympatholytics; D010862:Pilocarpine; C078949:FK 888; D019832:N-Methylscopolamine
keywords: Anxiety; Dorsal hippocampus; Elevated plus-maze; Lateral septum; NK(1) receptor; Pilocarpine