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A non-canonical GABAergic pathway to the VTA promotes unconditioned freezing.

ABSTRACT: Freezing is a conserved defensive behaviour that constitutes a major stress-coping mechanism. Decades of research have demonstrated a role of the amygdala, periaqueductal grey and hypothalamus as core actuators of the control of fear responses, including freezing. However, the role that other modulatory sites provide to this hardwired scaffold is not known. Here, we show that freezing elicited by exposure to electrical foot shocks activates laterodorsal tegmentum (LDTg) GABAergic neurons projecting to the VTA, without altering the excitability of cholinergic and glutamatergic LDTg neurons. Selective chemogenetic silencing of this inhibitory projection, but not other LDTg neuronal subtypes, dampens freezing responses but does not prevent the formation of conditioned fear memories. Conversely, optogenetic-activation of LDTg GABA terminals within the VTA drives freezing responses and elicits bradycardia, a common hallmark of freezing. Notably, this aversive information is subsequently conveyed from the VTA to the amygdala via a discrete GABAergic pathway. Hence, we unveiled a circuit mechanism linking LDTg-VTA-amygdala regions, which holds potential translational relevance for pathological freezing states such as post-traumatic stress disorders, panic attacks and social phobias.

SUBMITTER: Broussot L

PROVIDER: S-EPMC9763111 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature

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A non-canonical GABAergic pathway to the VTA promotes unconditioned freezing.

Broussot Loïc L Contesse Thomas T Costa-Campos Renan R Glangetas Christelle C Royon Léa L Fofo Hugo H Lorivel Thomas T Georges François F Fernandez Sebastian P SP Barik Jacques J

Molecular psychiatry 20220920 12

Freezing is a conserved defensive behaviour that constitutes a major stress-coping mechanism. Decades of research have demonstrated a role of the amygdala, periaqueductal grey and hypothalamus as core actuators of the control of fear responses, including freezing. However, the role that other modulatory sites provide to this hardwired scaffold is not known. Here, we show that freezing elicited by exposure to electrical foot shocks activates laterodorsal tegmentum (LDTg) GABAergic neurons project ...[more]

PMID: 36127430

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Dataset Information

A non-canonical GABAergic pathway to the VTA promotes unconditioned freezing.

Publications

A non-canonical GABAergic pathway to the VTA promotes unconditioned freezing.

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