Multiple context discrimination in adult rats: sex variability and dynamics of time-dependent generalization of an aversive memory

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 7, 2024

ABSTRACT Memory generalization can be defined as the transference of conditioned fear responses to novel contexts. It happens in systems consolidation, a time-dependent reduction discrimination precision due rearrangement brain regions supporting memory retrieval. To better understand fine temporal structure this process different sexes, young adult female and male rats were trained contextual conditioning task tested or three contexts either 2, 28 45 days later. A set neutral was selected graded levels expression compared training context obtained, albeit observed only males, not females, recent test - first number sexual dimorphisms detected. This asymmetry, however, disappeared over time partial generalization, with converging similar, higher values, grouped two levels, both sexes. In all experiments, females discriminators displayed lower than apparently valuing sensory modalities. is study compare between retrieving remote memories multiple contexts, allowing several dimorphic findings.

Language: Английский

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Examining sex differences in responses to footshock stress and the role of the metabotropic glutamate receptor 5: an [18F]FPEB and positron emission tomography study in rats

Neuropsychopharmacology, Journal Year: 2022, Volume and Issue: 48(3), P. 489 - 497

Published: Sept. 13, 2022

Language: Английский

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Sex difference in the facilitation of fear learning by prior fear conditioning

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: June 30, 2023

There is now ample evidence that the strength and underlying mechanisms of memory formation can be drastically altered by prior experience. However, work using rodent models on this topic has used only males as subjects, a result, we do know whether or not effects experience subsequent learning are similar in both sexes. As first step towards addressing shortcoming rats sexes were given auditory fear conditioning, conditioning with unsignaled shocks, followed an hour day later single pairing light shock. Fear for each was assessed measuring freezing behavior to cue fear-potentiated startle light. Results showed trained facilitated visual session when two training sessions separated one day. Females facilitation they spaced hour, but Contextual did support under any conditions. These results indicate mechanism which facilitates differs between sexes, set stage mechanistic studies understand neurobiological basis sex difference.

Language: Английский

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Lifting Laboratory Rats: A Survey of Methods, Handlers’ Reasons and Concerns, and Rat Behavioural Responses

Published: Jan. 1, 2023

Lifting mice by the tail is of animal welfare and scientific concern, but methods for lifting rats are little understood, potentially differing from mice. Using an online questionnaire we explored different laboratory rats, alongside reasons concerns reported handlers, rat behavioural responses. We received 249 valid responses handlers across research sectors, job roles, 26 countries (39% UK). Eight methods, plus ‘other’, were used; Shoulder saddle (39%), Chest-and-bottom support (20%) Tail (11%) most common. Regarding respondents’ using their main method, those selected ‘rat comfort’ significantly less frequently, ‘quick’ more than did users other methods. Most respondents had no about concerned that it caused ‘stress to rat’ support. Concerns speed, feasibility validity rare. Rats reportedly defecated more, sniffed hand less, when lifted Respondents who in Cupped hands approach, sniff attempt climb onto certain did. Findings suggest risks poor welfare. It also concerning common saddle, not appear better lifting. support, Cupping, Tunnel, some rarer may offer refined rats.

Language: Английский

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Key Parameters Required to Perform Contextual Fear Conditioning and Extinction in Adult Rats

Published: Jan. 1, 2023

Contextual fear conditioning is a behavioral paradigm used to assess hippocampal-dependent memory in experimental animals. Perception of the context depends on activation distinct population neurons hippocampus and hippocampal-related areas that process discrete aspects perception. In absence any putatively associated cue, becomes salient element may warn an upcoming aversive event; particular conditions, animals generalize this warning new or similar context. these studies we evaluated effects number sessions, unconditioned stimuli per acquisition session distribution extinction sessions determine under which conditions generalization occurred adult male female rats. We observed organization spacing were relevant factors contextual memories. Extinction with significantly greater robustness when spread over two days. Furthermore, results indicated exposure single 0.3 mA 0.5 s footshock different could produce context-specific fear, while more footshocks within produced response Notably, occurred, successive re-exposure generalized way paired exposure. Together, present findings identify clear procedural parameters amenable neural systems analysis three clinically outcomes conditioning, i.e., acquisition, storage extinction.

Language: Английский

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