Environmental Enrichment Facilitates Anxiety in Conflict-Based Tests but Inhibits Predator Threat-Induced Defensive Behaviour in Male Mice

Author(s)

dos Anjos-Garcia, Tayllon ; Kanashiro, Alexandre ; de Campos, Alline Cristina ; Coimbra, Norberto Cysne

• Document type: Journal article
• Source: NEUROPSYCHOBIOLOGY; v. N/A, p. 12-pg., 2022-01-13.

Abstract

Introduction: Environmental enrichment (EE) is a useful and sophisticated tool that improves rodents' well-being by stimulating social behaviour and cognitive, motor, and sensory functions. Exposure to EE induces neuroplasticity in different brain areas, including the limbic system, which has been implicated in the control of anxiety and fear. However, the effects of EE on ethologically relevant naturalistic behaviours, such as those displayed by prey in the presence of predators, remain largely unexplored. Material and Methods: In the present study, we investigated anxiety- and panic attack-like behaviours in a predator (cat)-prey confrontation paradigm and compared them with those in classical assays, such as the elevated plus-maze (EPM), marble-burying, and open field tests (OFTs), using C57BL/6J male mice housed in enriched or standard environments for 6 weeks. Results: We observed that EE exposure caused enhancement of the levels of anxiety-like behaviours in the EPM and OFTs, increasing risk assessment (an anxiety-related response), and decreasing escape (a panic attack-like response) behaviours during exposure to the predator versus prey confrontation paradigm. Conclusion: Taken together, our findings suggest that enriched external environments can modify the processing of fear- and anxiety-related stimuli in dangerous situations, changing the decision-making defensive strategy. (AU)

• FAPESP's process: 17/11855-8 - Study of corpus striatum and ventral mesencephalon endocanabinoid influence on neostriato-nigro-tectal GABAergic pathways during panic reactions of rodents threatened by venomous snakes
• Grantee: Norberto Cysne Coimbra
• Support Opportunities: Regular Research Grants
• FAPESP's process: 07/01174-1 - Study of the Involvement of opioid-, serotonergic- and noradrenergic-mechanisms of the pain endogenous inhibitory system in antinociceptive processes induced by oriented escape reactions evoked by chemical stimulation of the merdial hypothalamus
• Grantee: Norberto Cysne Coimbra
• Support Opportunities: Regular Research Grants
• FAPESP's process: 20/15050-7 - Study of the role played by endocannabinoid and endovaniloid signalling in the pallidum on the activity of the neostriatum-pallido-nigral disinhibitory and nigro-tectal inhibitory pathways during the organization of innate fear of animals confronted to snakes
• Grantee: Norberto Cysne Coimbra
• Support Opportunities: Regular Research Grants
• FAPESP's process: 12/03798-0 - Involvement of opioid and endocanabinoid receptors of the substantia nigra on the activity of Nigro-Tectal GABAergic pathways during defensive behaviour elicited by rodents confronted with venomous snakes
• Grantee: Norberto Cysne Coimbra
• Support Opportunities: Regular Research Grants