Upregulation of FosB/Delta FosB in limbic circuits after tooth exodontia-induced occlusal instability in an experimental model of unpredictable chronic stress

Author(s):Show less -

Nascimento, Glauce Crivelaro ^[1] ; de Paula, Bruna Balbino ^[2] ; Ferrari, Daniele P. ^[3] ; Iyomasa, Daniela Mizusaki ^[2] ; Pereira, Yamba C. L. ^[1] ; Pedrazzi, Joao F. ^[3] ; Bortolanza, Mariza ^[1] ; Issy, Ana Carolina ^[1] ; Mardegan Issa, Joao Paulo ^[1] ; Leite-Panissi, Christie R. A. ^[2] ; Iyomasa, Mamie Mizusaki ^[1] ; Del-Bel, Elaine ^[1]

Affiliation

^[1] Univ Sao Paulo, Sch Dent Ribeirao Preto, Dept Oral & Basic Biol, BR-14040904 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Sch Philosophy Sci & Letters Ribeirao Preto, Dept Psychol, BR-14040901 Ribeirao Preto, SP - Brazil

^[3] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Neurol, BR-14040900 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: Brain Research Bulletin; v. 176, p. 142-150, NOV 2021.
• Web of Science Citations: 0

Abstract

Psychological stress and occlusal alterations are contributing etiologic factors for temporomandibular and muscular disorders in the orofacial area. The neural modulation recruited for this relationship, however, is not elucidated. The aim of this study was to investigate potential central mechanisms involved in the exodontiainduced occlusal instability associated with unpredictable chronic stress (UCS). Male adult Wistar rats were submitted to occlusal instability (unilateral molar teeth extraction) and/or to a UCS protocol and treated with diazepam or vehicle. The anxiety-like behavior was evaluated by elevated plus maze (EPM) and open field (OF) tests. Limbic structures such as the central nucleus of the amygdala (CeA), paraventricular nucleus of the hypothalamus (PVN), dorsal periaqueductal gray matter (dPAG) and nucleus accumbens core (NAc) were analyzed for expression of FosB/Delta FosB (immediate early genes) by immunohistochemistry. Exodontia and/or UCS decreased the time spent in the open arms at the EPM and the distance travelled at the OF, and increased the immobility time at the OF, suggesting anxiety-like behavior. In addition, exodontia induction resulted in an upregulation of FosB/Delta FosB in the CeA, PVN and dPAG, while UCS and exodontia + UCS upregulate FosB/Delta FosB immunoreactivity in the CeA, PVN, dPAG and NAc. Treatment with diazepam decreased the expression of FosB/ Delta FosB in all analyzed structures of animals subject to UCS and exodontia + UCS, while promoted a reduction in the FosB/Delta FosB expression in the CeA, PVN and dPAG in animals subject to exodontia. Our findings showed an anxiogenic effect of exodontia and UCS, which is correlated with intranuclear neuron activation of limbic structures in a spatially dependent manner and that is prevented by the administration of diazepam. (AU)

• FAPESP's process: 17/24304-0 - New perspectives in the use of drugs that modify atypical neurotransmitters in the treatment of neuropsychiatric disorders
• Grantee: Francisco Silveira Guimaraes
• Support type: Research Projects - Thematic Grants
• FAPESP's process: 18/05146-7 - Morphological differentiation of NG2 and astrocyte in striatum of rats under an experimental model of parkinsonism: efficacy of doxycycline on neuroinflammation process
• Grantee: Glauce Crivelaro Do Nascimento
• Support type: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 14/25029-4 - Contribution of the neuroinflamation to L-DOPA induced dyskinesia
• Grantee: Elaine Aparecida Del Bel Belluz Guimarães
• Support type: Research Projects - Thematic Grants
• FAPESP's process: 15/03053-3 - Evaluation of medial pterygoid muscle and brain structures related to orofacial nociception and emotional behavior in an animal model of chronic stress and masticatory hypofunction
• Grantee: Glauce Crivelaro Do Nascimento
• Support type: Scholarships in Brazil - Post-Doctorate