Fabrício Calvo1,2,3,4, Bruno Lobão-Soares1,5,6,4, Renato Leonardo de Freitas1,7,8, Tatiana Paschoalin-Maurin1,6,4, Tayllon Dos Anjos-Garcia1,4, Priscila Medeiros1,4, Juliana Almeida da Silva1,4, Thelma Anderson Lovick9,6, Norberto Cysne Coimbra1,6,7,10,4. 1. 1 Laboratory of Neuroanatomy & Neuropsychobiology, Department of Pharmacology, School of Medicine of Ribeirão Preto of the University of São Paulo (FMRP-USP), Ribeirão Preto (SP), Brazil. 2. 3 Department of Pharmacology, São Lucas College, Porto Velho (RO), Brazil. 3. 4 Aparício Carvalho Integrative College, Porto Velho (RO), Brazil. 4. 9 Ophidiarium LNN-FMRP-USP/INeC, Ribeirão Preto School of Medicine of the University of São Paulo (FMRP-USP), Ribeirão Preto (SP), Brazil. 5. 5 Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte (UFRN), Natal (RN), Brazil. 6. 6 Instituto de Neurociências e Comportamento (INeC), Ribeirão Preto (SP), Brazil. 7. 7 Laboratory of Neurobiology of Pain and Emotions and Multi-User Centre of Neuroelectrophysiology, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo, Ribeirão Preto (SP), Brazil. 8. 10 Biomedical Sciences Institute, Federal University of Alfenas (UNIFAL-MG), Alfenas (MG), Brazil. 9. 2 School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK. 10. 8 NAP-USP-Neurobiology of Emotions Research Centre (NuPNE), Ribeirão Preto School of Medicine of the University of São Paulo (FMRP-USP), Ribeirão Preto (SP), Brazil.
Abstract
BACKGROUND: There is a controversy regarding the key role played by opioid peptide neurotransmission in the modulation of panic-attack-related responses. AIMS: Using a prey versus rattlesnakes paradigm, the present work investigated the involvement of the endogenous opioid peptide-mediated system of the inferior colliculus in the modulation of panic attack-related responses. METHODS: Wistar rats were pretreated with intracollicular administration of either physiological saline or naloxone at different concentrations and confronted with rattlesnakes ( Crotalus durissus terrificus). The prey versus rattlesnake confrontations were performed in a polygonal arena for snakes. The defensive behaviors displayed by prey (defensive attention, defensive immobility, escape response, flat back approach and startle) were recorded twice: firstly, over a period of 15 min the presence of the predator and a re-exposure was performed 24 h after the confrontation, when animals were exposed to the experimental enclosure without the rattlesnake. RESULTS: The intramesencephalic non-specific blockade of opioid receptors with microinjections of naloxone at higher doses decreased both anxiety- (defensive attention and flat back approach) and panic attack-like (defensive immobility and escape) behaviors, evoked in the presence of rattlesnakes and increased non-defensive responses. During the exposure to the experimental context, there was a decrease in duration of defensive attention. CONCLUSIONS: These findings suggest a panicolytic-like effect of endogenous opioid receptors antagonism in the inferior colliculus on innate (panic attack) and conditioned (anticipatory anxiety) fear in rats threatened by rattlesnakes.
BACKGROUND: There is a controversy regarding the key role played by opioid peptide neurotransmission in the modulation of panic-attack-related responses. AIMS: Using a prey versus rattlesnakes paradigm, the present work investigated the involvement of the endogenous opioid peptide-mediated system of the inferior colliculus in the modulation of panic attack-related responses. METHODS:Wistar rats were pretreated with intracollicular administration of either physiological saline or naloxone at different concentrations and confronted with rattlesnakes ( Crotalus durissus terrificus). The prey versus rattlesnake confrontations were performed in a polygonal arena for snakes. The defensive behaviors displayed by prey (defensive attention, defensive immobility, escape response, flat back approach and startle) were recorded twice: firstly, over a period of 15 min the presence of the predator and a re-exposure was performed 24 h after the confrontation, when animals were exposed to the experimental enclosure without the rattlesnake. RESULTS: The intramesencephalic non-specific blockade of opioid receptors with microinjections of naloxone at higher doses decreased both anxiety- (defensive attention and flat back approach) and panic attack-like (defensive immobility and escape) behaviors, evoked in the presence of rattlesnakes and increased non-defensive responses. During the exposure to the experimental context, there was a decrease in duration of defensive attention. CONCLUSIONS: These findings suggest a panicolytic-like effect of endogenous opioid receptors antagonism in the inferior colliculus on innate (panic attack) and conditioned (anticipatory anxiety) fear in rats threatened by rattlesnakes.
Authors: Rafael C Almada; Luiz Luciano Falconi-Sobrinho; Juliana A da Silva; Carsten T Wotjak; Norberto C Coimbra Journal: Psychopharmacology (Berl) Date: 2022-06-02 Impact factor: 4.415
Authors: Natasha J Anstey; Vijayakumar Kapgal; Emma R Wood; Oliver Hardt; Peter C Kind; Shashank Tiwari; Thomas C Watson; Anna K H Toft; Owen R Dando; Felicity H Inkpen; Paul S Baxter; Zrinko Kozić; Adam D Jackson; Xin He; Mohammad Sarfaraz Nawaz; Aiman Kayenaat; Aditi Bhattacharya; David J A Wyllie; Sumantra Chattarji Journal: Mol Autism Date: 2022-07-18 Impact factor: 6.476