Study of the neural mechanisms underlying vulnerability for expression of panic-related behaviors in different mouse strains

• Grant number: 20/01231-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2020
• End date: February 28, 2021
• Field of knowledge: Biological Sciences - Pharmacology - Neuropsychopharmacology
• Principal Investigator: Hélio Zangrossi Júnior
• Grantee: Mirian Félix de Carvalho
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Panic disorder is characterized by the recurrence of unexpected panic attacks. Panic attacks can be triggered by inhalation of high CO2 concentrations or low O2 concentrations. Results recently obtained by our research group show that escape expression, a behavior associated with panic, evoked by exposure to CO2 is different among 3 mouse strains (C57BL/6, Balb cand Swiss), suggesting a distinctive vulnerability profile to this panic genic stimulus. However, the neural substrates and neurochemical bases behind this phenomenon are still unknown. In this work we will evaluate the involvement of serotonin, nitric oxide (NO) and GABA in the expression of escape by male and female mice, of the 3 strains mentioned above, submitted to an environment with 20% CO2. It will also be evaluated if these 3 strains differ in the expression of defensive responses evoked in an environment with low O2concentration. This will be done by means of the immunohistochemically labeling of the enzymes tryptophan hydroxylase, neuronal nitric oxide synthase (nNOS) and glutamate decarboxylase (GAD67), for assessing the role of serotonergic, nitrergic and GABAergicneurons, respectively, in panic-associated areas, such as the dorsal raphe nucleus (DRN), the dorsal periaqueductal gray matter (DPAG) and the medial hypothalamus. In the same slices, we will also detected the number of cells stained for the protein c-Fos, as a marker of neuronal activity.