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The RUB Cage: Respiration-Ultrasonic Vocalizations-Behavior Acquisition Setup for Assessing Emotional Memory in Rats.

Hegoburu C, Shionoya K, Garcia S, Messaoudi B, Thévenet M, Mouly AM - Front Behav Neurosci (2011)

Bottom Line: In addition, the bottom of the plethysmograph was equipped with a shock-floor allowing foot-shock delivery, and the top received tubing for odor presentations.Using this experimental setup we first described the characteristics of respiration and USV in different behaviors and emotional states.The present setup may be valuable in providing a clearer appraisal of the physiological and behavioral changes that occur during acquisition as well as retrieval of emotional memory.

View Article: PubMed Central - PubMed

Affiliation: Team "Olfaction: From Coding to Memory", Lyon Neuroscience Research Center, INSERM U1028, CNRS UMR5292 Lyon, France.

ABSTRACT
In animals, emotional memory is classically assessed through pavlovian fear conditioning in which a neutral novel stimulus (conditioned stimulus) is paired with an aversive unconditioned stimulus. After conditioning, the conditioned stimulus elicits a fear response characterized by a wide range of behavioral and physiological responses. Despite the existence of this large repertoire of responses, freezing behavior is often the sole parameter used for quantifying fear response, thus limiting emotional memory appraisal to this unique index. Interestingly, respiratory changes and ultrasonic vocalizations (USV) can occur during fear response, yet very few studies investigated the link between these different parameters and freezing. The aim of the present study was to design an experimental setup allowing the simultaneous recording of respiration, USV, and behavior (RUB cage), and the offline synchronization of the collected data for fine-grain second by second analysis. The setup consisted of a customized plethysmograph for respiration monitoring, equipped with a microphone capturing USV, and with four video cameras for behavior recording. In addition, the bottom of the plethysmograph was equipped with a shock-floor allowing foot-shock delivery, and the top received tubing for odor presentations. Using this experimental setup we first described the characteristics of respiration and USV in different behaviors and emotional states. Then we monitored these parameters during contextual fear conditioning and showed that they bring complementary information about the animal's anxiety state and the strength of aversive memory. The present setup may be valuable in providing a clearer appraisal of the physiological and behavioral changes that occur during acquisition as well as retrieval of emotional memory.

No MeSH data available.


Related in: MedlinePlus

Evolution of freezing, respiration, and ultrasonic vocalizations (USV) during contextual fear conditioning in two groups of animals trained with different shock intensities: 0. 4 versus 0.8 mA. The three parameters were collected at different periods of the acquisition (left part) and retention (right part) sessions: beginning (first foot-shock delivery), middle (after 5 foot-shocks), and end (after 10 foot-shocks). (A) Freezing behavior (mean ± SEM). (B) Respiratory frequency (mean ± SEM). (C) USV response duration (mean ± SEM). *Significant difference between 0.4 and 0.8 mA animals, p < 0.05.
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Figure 6: Evolution of freezing, respiration, and ultrasonic vocalizations (USV) during contextual fear conditioning in two groups of animals trained with different shock intensities: 0. 4 versus 0.8 mA. The three parameters were collected at different periods of the acquisition (left part) and retention (right part) sessions: beginning (first foot-shock delivery), middle (after 5 foot-shocks), and end (after 10 foot-shocks). (A) Freezing behavior (mean ± SEM). (B) Respiratory frequency (mean ± SEM). (C) USV response duration (mean ± SEM). *Significant difference between 0.4 and 0.8 mA animals, p < 0.05.

Mentions: Concerning freezing behavior, in both groups, high levels of freezing were observed from the middle to the end of the session (Figure 6A, left part). A two-way (group, period) ANOVA for repeated-measures showed a significant effect for group [F(1,14) = 10.49, p < 0.01] and for period [F(2,28) = 87.51, p < 0.0001]. Further comparisons revealed that 0.8 mA-shock animals displayed higher freezing rate than 0.4 mA-shock animals, for the beginning and end periods (p < 0.05). Concerning respiration (Figure 6B, left part), in both groups, respiratory frequency decreased throughout the session. The ANOVA revealed a significant effect for group [F(1,14) = 20.86, p < 0.005] and period [F(2,28) = 50.02, p < 0.0001]. Further pair-wise comparisons showed that 0.8 mA-shock animals displayed a lower respiratory frequency than 0.4 mA-shock animals, for the beginning, middle, and end periods (p < 0.05). Concerning USV, 50% (5/10) of the rats in the 0.4 mA-shock group emitted USV in response to shock delivery, against 100% (6/6; Chi-square test, p = 0.027) in the 0.8 mA-shock group. Additionally when considering the duration of USV emission during the session in both groups (Figure 6C, left part), the ANOVA revealed a main effect of group [F(1,14) = 7.07, p < 0.05] and period [F(2,28) = 27.56, p < 0.05]. Post hoc comparisons showed that 0.8 mA-shock animals displayed longer duration USV emission than 0.4 mA-shock animals, all along the session (p < 0.05). The increase in USV duration was mainly due to the fact that the average number of calls per rat was higher in 0.8 mA-shock rats (1518 ± 359) than in 0.4 mA-shock animals (620 ± 126; p < 0.05).


The RUB Cage: Respiration-Ultrasonic Vocalizations-Behavior Acquisition Setup for Assessing Emotional Memory in Rats.

Hegoburu C, Shionoya K, Garcia S, Messaoudi B, Thévenet M, Mouly AM - Front Behav Neurosci (2011)

Evolution of freezing, respiration, and ultrasonic vocalizations (USV) during contextual fear conditioning in two groups of animals trained with different shock intensities: 0. 4 versus 0.8 mA. The three parameters were collected at different periods of the acquisition (left part) and retention (right part) sessions: beginning (first foot-shock delivery), middle (after 5 foot-shocks), and end (after 10 foot-shocks). (A) Freezing behavior (mean ± SEM). (B) Respiratory frequency (mean ± SEM). (C) USV response duration (mean ± SEM). *Significant difference between 0.4 and 0.8 mA animals, p < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC3101376&req=5

Figure 6: Evolution of freezing, respiration, and ultrasonic vocalizations (USV) during contextual fear conditioning in two groups of animals trained with different shock intensities: 0. 4 versus 0.8 mA. The three parameters were collected at different periods of the acquisition (left part) and retention (right part) sessions: beginning (first foot-shock delivery), middle (after 5 foot-shocks), and end (after 10 foot-shocks). (A) Freezing behavior (mean ± SEM). (B) Respiratory frequency (mean ± SEM). (C) USV response duration (mean ± SEM). *Significant difference between 0.4 and 0.8 mA animals, p < 0.05.
Mentions: Concerning freezing behavior, in both groups, high levels of freezing were observed from the middle to the end of the session (Figure 6A, left part). A two-way (group, period) ANOVA for repeated-measures showed a significant effect for group [F(1,14) = 10.49, p < 0.01] and for period [F(2,28) = 87.51, p < 0.0001]. Further comparisons revealed that 0.8 mA-shock animals displayed higher freezing rate than 0.4 mA-shock animals, for the beginning and end periods (p < 0.05). Concerning respiration (Figure 6B, left part), in both groups, respiratory frequency decreased throughout the session. The ANOVA revealed a significant effect for group [F(1,14) = 20.86, p < 0.005] and period [F(2,28) = 50.02, p < 0.0001]. Further pair-wise comparisons showed that 0.8 mA-shock animals displayed a lower respiratory frequency than 0.4 mA-shock animals, for the beginning, middle, and end periods (p < 0.05). Concerning USV, 50% (5/10) of the rats in the 0.4 mA-shock group emitted USV in response to shock delivery, against 100% (6/6; Chi-square test, p = 0.027) in the 0.8 mA-shock group. Additionally when considering the duration of USV emission during the session in both groups (Figure 6C, left part), the ANOVA revealed a main effect of group [F(1,14) = 7.07, p < 0.05] and period [F(2,28) = 27.56, p < 0.05]. Post hoc comparisons showed that 0.8 mA-shock animals displayed longer duration USV emission than 0.4 mA-shock animals, all along the session (p < 0.05). The increase in USV duration was mainly due to the fact that the average number of calls per rat was higher in 0.8 mA-shock rats (1518 ± 359) than in 0.4 mA-shock animals (620 ± 126; p < 0.05).

Bottom Line: In addition, the bottom of the plethysmograph was equipped with a shock-floor allowing foot-shock delivery, and the top received tubing for odor presentations.Using this experimental setup we first described the characteristics of respiration and USV in different behaviors and emotional states.The present setup may be valuable in providing a clearer appraisal of the physiological and behavioral changes that occur during acquisition as well as retrieval of emotional memory.

View Article: PubMed Central - PubMed

Affiliation: Team "Olfaction: From Coding to Memory", Lyon Neuroscience Research Center, INSERM U1028, CNRS UMR5292 Lyon, France.

ABSTRACT
In animals, emotional memory is classically assessed through pavlovian fear conditioning in which a neutral novel stimulus (conditioned stimulus) is paired with an aversive unconditioned stimulus. After conditioning, the conditioned stimulus elicits a fear response characterized by a wide range of behavioral and physiological responses. Despite the existence of this large repertoire of responses, freezing behavior is often the sole parameter used for quantifying fear response, thus limiting emotional memory appraisal to this unique index. Interestingly, respiratory changes and ultrasonic vocalizations (USV) can occur during fear response, yet very few studies investigated the link between these different parameters and freezing. The aim of the present study was to design an experimental setup allowing the simultaneous recording of respiration, USV, and behavior (RUB cage), and the offline synchronization of the collected data for fine-grain second by second analysis. The setup consisted of a customized plethysmograph for respiration monitoring, equipped with a microphone capturing USV, and with four video cameras for behavior recording. In addition, the bottom of the plethysmograph was equipped with a shock-floor allowing foot-shock delivery, and the top received tubing for odor presentations. Using this experimental setup we first described the characteristics of respiration and USV in different behaviors and emotional states. Then we monitored these parameters during contextual fear conditioning and showed that they bring complementary information about the animal's anxiety state and the strength of aversive memory. The present setup may be valuable in providing a clearer appraisal of the physiological and behavioral changes that occur during acquisition as well as retrieval of emotional memory.

No MeSH data available.


Related in: MedlinePlus