Defensive behaviors and brain regional activation changes in rats confronting a snake

Mendes-Gomes, Joyce; Motta, Simone Cristina; Bindi, None Ricardo P.; Oliveira, Amanda Ribeiro de; Ullah, Farid; Baldo, Marcus Vinícius C.; Coimbra, Norberto Cysne; Canteras, Newton S.; Blanchard, D. Caroline

doi:10.1016/j.bbr.2020.112469

Cited by 34 publications

(39 citation statements)

References 32 publications

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“…Innate defensive behaviours are generated by the medial hypothalamic defensive system 9 , consisting of the anterior hypothalamic nucleus (AHN) 10, 11 , the dorsomedial and central region of the ventromedial hypothalamus (VMHdm/c) 10, 12–14 and the dorsal premammillary nucleus (PMD) 9, 15 . These three distinct nuclei are densely interconnected and become highly active upon predator exposure 16–19 to control motor outputs at the level of periaqueductal gray (PAG) 7, 12, 20, 21 . In both rodents and non-human primates, direct stimulation of the medial hypothalamic defensive system evokes strong defensive responses, such as escape flight, freezing, sympathetic activation, and panic, while its inhibition reduces defensive responses to predator threats 22–25 .…”

Section: Mainmentioning

confidence: 99%

Hippocampal-hypothalamic circuit controls context-dependent innate defensive responses

Bang

Sunstrum

Garand

et al. 2021

Preprint

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Preys use their memory - where they sensed a predatory threat and whether a safe shelter is nearby - to dynamically control their survival instinct to avoid harm and reach safety. However, it remains unknown which brain regions are involved, and how such top-down control of innate behaviour is implemented at the circuit level. Here, we show that the anterior hypothalamic nucleus (AHN) is best positioned to perform this task as an exclusive target of the hippocampus (HPC) within the medial hypothalamic defense system. Selective optogenetic stimulation and inhibition of hippocampal inputs to the AHN revealed that the HPC→AHN pathway not only mediates the contextual memory of predator threats but also controls the goal-directed escape by transmitting information about the surrounding environment. These results reveal a new mechanism for experience-dependent, top-down control of innate defensive behaviours.

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Section: Mainmentioning

confidence: 99%

Hippocampal-hypothalamic circuit controls context-dependent innate defensive responses

Bang

Sunstrum

Garand

et al. 2021

Preprint

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“…The PMd is a key component of the hypothalamic defense system, and is strongly activated by various imminent threats (Cezario et al, 2008). Dangerous stimuli that activate the rodent PMd are extremely diverse, and include carbon dioxide (Johnson et al, 2011), several predators (cats, snakes and ferrets) (Mendes-Gomes et al, 2020) as well as aversive lights and noises (Kim et al, 2017). Additionally, the PMd is also activated by contexts fear conditioned with shocks (Canteras et al, 2008) and social defeat (Faturi et al, 2014), indicating that it may play a role in coordinating defensive behaviors to both innate and conditioned threats.…”

Section: Introductionmentioning

confidence: 99%

Dorsal premammillary projection to periaqueductal gray controls escape vigor from innate and conditioned threats

Wang¹,

Schuette²,

La-Vu³

et al. 2021

Preprint

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Escape from threats has paramount importance for survival. However, it is unknown if a single circuit controls escape from innate and conditioned threats. The hypothalamic dorsal premammillary nucleus (PMd) may control escape, as it is activated by escape-inducing threats and projects to the region most implicated in flight, the dorsolateral periaqueductal gray (dlPAG). We show that in mice cholecystokinin (cck)-expressing PMd cells are activated during escape, but not other defensive behaviors. PMd-cck ensemble activity can also predict future escape. Furthermore, PMd inhibition decreases escape speed from both innate and conditioned threats. Inhibition of the PMd-cck projection to the dlPAG also decreased escape speed. Lastly, human fMRI data show that a posterior hypothalamic-to-dlPAG pathway increased activity during exposure to aversive images, indicating that a similar pathway may possibly have a related role in humans. Our data identify the PMd as a central node of the escape network.

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“…PAG columns (especially rPAGdm and rPAGl) are mobilized during both social and restraint stress. These columns receive projections from PMD and LHAjd and may be the effector sites from the septo-hippocampal-hypothalamic circuit since they are also mobilized during other aversive situations as predatory encounter and foot shock 15,23,25,26,58 . Also, the mobilization of PAGdm,l was similar between the first and last exposure to social stress.…”

Section: Discussionmentioning

confidence: 99%

Dynamics in brain activation and behaviour in acute and repeated social defensive motivated behaviour

Almeida

Baldo

Motta

2021

Preprint

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In nature, confrontations between conspecifics are recurrent and related, in general, to the lack of resources such as food and territory. In this sense, adequate defence against a conspecific aggressor is essential for the individual’s survival and the group integrity. However, repeated social defeat is a significant stressor, promoting several behavioural changes, including on social defence per se. But what would be the neural basis of these behavioural changes? To explore some hypotheses about this, we investigated the effects of repeated social stress on neural circuits underlying the motivated behaviour social defence in male mice. The hypothalamus is an essential centre of these circuits. Different hypothalamic structures receive information about the conspecific from the medial amygdala and the bed nucleus of the terminal stria. Furthermore, the hypothalamus can receive environmental information via the septo-hippocampal-hypothalamic circuit. Both information is processed by the dorsal premammillary nucleus (PMD) and the ventrolateral portion of the ventromedial nucleus of the hypothalamus, which communicate with the periaqueductal grey, an important downstream site for behavioural emission. During our analysis, we observed that animals re-exposed three times to the aggressor spent more time in passive defence during their last exposure than in their first one. These animals also present a smaller mobilization of areas related to the processing of conspecific cues. In contrast, we did not observe changes in the PMD mobilization. Therefore, our data indicate that the balance between the activity of circuits related to conspecific processing and the PMD determines the pattern of social defence behaviour. Changes in this balance may be the basis of the adaptations in social defence after repeated social defeat.

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Defensive behaviors and brain regional activation changes in rats confronting a snake

Cited by 34 publications

References 32 publications

Hippocampal-hypothalamic circuit controls context-dependent innate defensive responses

Hippocampal-hypothalamic circuit controls context-dependent innate defensive responses

Dorsal premammillary projection to periaqueductal gray controls escape vigor from innate and conditioned threats

Dynamics in brain activation and behaviour in acute and repeated social defensive motivated behaviour

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