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Defensive behaviors and brain regional activation changes in rats confronting a snake
Joyce Mendes-Gomes1, Simone Cristina Motta2, Ricardo Passoni Bindi2
1Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP 14049-900, Brazil; Ophidiarium LNN-FMRP-USP/INeC, Ribeirão Preto School of Medicine of the University of São Paulo (FMRP-USP), Ribeirão Preto (SP), 14049-900, Brazil; NAP-USP-Neurobiology of Emotions Research Centre (NuPNE), Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto (SP), 14049-900, Brazil.
Rats exhibit freezing and spatial avoidance when threatened by snakes. Brain activation patterns, particularly in the hypothalamus, differ from responses to other predators, highlighting unique threat detection pathways.
Area of Science:
- Neuroscience
- Ethology
- Comparative Psychology
Background:
- Predator threats elicit complex defensive behaviors in prey animals.
- Understanding neural mechanisms of threat detection is crucial for behavioral science.
Purpose of the Study:
- To investigate behavioral and brain activation changes in rats exposed to a nonmammalian predator, the rattlesnake.
- To compare neural responses to snake threat with those elicited by other predator types.
Main Methods:
- Rats were exposed to a rattlesnake (Crotalus durissus terrificus).
- Behavioral responses (freezing, stretch-attend, spatial avoidance) were recorded.
- Brain regional activation was assessed using Fos expression analysis.
Main Results:
- Rats displayed significant freezing, stretch-attend, and spatial avoidance behaviors.
- Brain activation patterns showed Fos increases in the amygdala, hypothalamus, and periaqueductal gray.
- Hypothalamic activation differed from responses to cat predators or conspecifics, with notable VMH and lateral hypothalamus involvement.
Conclusions:
- Snake threat elicits distinct behavioral and neural responses in rats.
- Specific hypothalamic nuclei and their connections are critical for processing snake-related threats and spatial avoidance.
- These findings contribute to understanding predator-prey interactions and neural threat detection circuits.
