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P.4.b.008 Beta-adrenoceptor stimulation by isoproterenol promotes olfactory fear conditioning in rats
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P.4.b. Anxiety disorders and anxiolytics − Anxiety disorders (basic)
P.4.b.008 Beta-adrenoceptor stimulation by isoproterenol promotes olfactory fear conditioning in rats 1 Universidade E. Pavesi1 ° , N.S. Canteras2 , A.P. Carobrez3 . Federal de Santa Catarina, Dept. of Farmacologia, Florian´opolis, Brazil; 2 Universidade de S˜ao Paulo, Dept. of Anatomia, S˜ao Paulo, Brazil; 3 Universidade de Santa Catarina, Dept. of Farmacologia, Florian´opolis, Brazil
Purpose: Clinical studies have reported that beta-adrenoceptor agonists like isoproterenol (ISO), induced anxiogenic responses by sympathetic stimulation, and could promote panic attacks in humans. In rodents, beta-adrenoceptors within the dorsal premammillary nucleus (PMd) have been shown to mediate defensive responses toward predator odor [1]. PMd has also been shown to mediate the expression of conditioned fear responses to the shockpaired odor [2] and beta-adrenoceptor antagonist applied to the PMd reduced the defensive behavior elicited by the olfactory fear conditioning (OFC) stimulus [3]. It remains to be tested whether the beta-adrenoceptors activation within the PMd could support fear conditioning as an unconditioned stimulus (US) to induce the OFC. Methods: Seven days after male Wistar rats had received a guide cannula aimed at the PMd, they were submitted to the OFC protocol consisting of 2 phases: the acquisition (2 sessions) and the expression (3 sessions), spaced 24 hours each other. In Experiment 1, on day 1, rats were familiarized with the conditioning chamber. On the following day, they received microinjections (0.3ml) of PBS or ISO (10 or 40nmol) 5 min before the amylacetate (AA) exposure (CS1 -250 ml, 5%). The total exposure time to the AA was 3min and 20s or 10min. The OFC expression phase was set in an odor box comprising an open and an enclosed communicating compartment. The sessions were: familiarization to chamber (neutral odor); CS1 test (AA odor) and CS2 test (neutral odor). In Experiment 2, rats were divided to receive Atenolol (b1-antagonist, 40nmol) or PBS 5 min prior to conditioning session with ISO40 microinjection. In Experiment 3, the animals received intraperitoneal injections of either saline or nadolol (10 mg/Kg), a b-blocker that does not cross the blood-brain barrier, 30 min before the ISO40 conditioning session. During CS1 and CS2 tests, the percentage of time the rats spent near the odor source (%AT), and of time spent in a hidden compartment (%HT) were taken as an index of defensive behavior. Results: In Exp. 1, ANOVA repeated measure followed by Newman-Keuls revealed that ISO induced the acquisition of OFC. Subjects exposed to AA during 10min showed a significant decrease in the %AT (PBS; 30.1±3.4; ISO10; 10.6±1.9; ISO40; 9.2±1.5) and increased %HT (PBS; 37.5±4.4; ISO10; 76.3±4.6; ISO40; 78.5±3.0) during the CS1 session. The same profile of results was obtained during the CS2 session [PBS(%AT; 28.5±3.8; %HT; 36.1±6.1); ISO10 (%AT; 10.7±1.9; %HT; 72.1±4.0); ISO40 (%AT; 10.0±1.4; %HT; 73.6±2.0)]. In Exp 2, Atenolol prevented the ISO40 conditioning [CS1 (%AT; 31.6±3.8; %HT; 40.6±3.9); CS2 (%AT = 30.4±2.5; %HT = 38.3±4.0)]. In Exp. 3, the results failed to show any statistical difference between subjects that received systemic nadolol treatment before conditioning to ISO40. Conclusions: The present findings demonstrate that badrenergic activation in the PMd could function as an interoceptive-US, promoting a robust US-CS association. The anxiogenic effect of ISO was mainly due to b1-adrenoceptors
activation. Furthermore, the lack of systemic nadolol effect on ISO-OFC conditioning suggest an ascending PMd activation to prosencephalic areas. The results suggest the OFC paradigm as an experimental tool to test brain structures responsible to promote fear conditioning. Financial Supports: CNPq, CAPES, FAPESP, UFSC. References [1] Do Monte, F.H., Canteras, N.S., Fernandes, D., Assreuy, J., Carobrez, A.P., 2008 New perspectives on beta-adrenergic mediation of innate and learned fear responses to predator odor. The Journal of Neuroscience 28, 13296–13302. [2] Canteras, N.S., Kroon, J.A., Do-Monte, F.H., Pavesi, E., Carobrez, A.P., 2008 Sensing danger through the olfactory system: the role of the hypothalamic dorsal premammillary nucleus. Neuroscience Biobehavioral Reviews 32, 1228–1235. [3] Pavesi, E., Canteras, N.S., Carobrez, A.P., 2009 P.4.b.006 Atenolol impairs the acquisition and expression of olfactory fear conditioning in rats. European Neuropsychopharmacology 19, S599-S600.
P.4.b.009 Posttraumatic stress disorder and inflammation G. Mkrtchyan1 ° , L. Hovhannisyan1 , A. Boyajyan1 , M. Tadevosyan2 , A. Kalashyan2 , S. Sukiasian2 . 1 Institute of Molecular Biology of Armenian National Academy of Sciences, Laboratory of Macromolecular Complexes, Yerevan, Rep. of Armenia; 2 Ministry of Labour and Social Affairs of Armenia, Stress Center, Yerevan, Rep. of Armenia Background: Post-Traumatic Stress Disorder (PTSD) may develop following exposure to a traumatic event and is associated with debilitating physical and psychological health declines. Symptoms of PTSD include re-experiencing of the traumatic event through intrusive dreams or thoughts; physiologic arousal to stimuli that represent the trauma; numbing of feelings and avoidance of thoughts, feelings, people, and activities that symbolize the trauma. Several studies have reported immune function alterations in individuals with PTSD suggesting that low-grade inflammatory response is involved in PTSD pathogenesis on a chronic stage of the disease. However, the data are inconclusive, leading to an insufficient understanding of the role of inflammatory reactions in PTSD. Purpose: The aim of this study was to study some indicators of inflammation in PTSD-affected subjects and to perform correlation analyses between these parameters and clinical features of the disease. For this purpose we have examined 17 PTSD patients, combat veterans, diagnosed by application of the Clinical Administered PTSD Scale (CAPS). Age- and gender-matched 16 healthy subjects without any history of physical or sexual abuse or other major trauma, defined as being free of current or past psychiatric disorders served as a control group. Methods: Among the indicators of the inflammatory response, circulating immune complexes (CICs) and pro-inflammatory cytokine, IL-1b, were determined in the blood serum samples of patients and controls. CICs were measured using a C1q- and C3d-binding ELISA kit. The concentration of CICs was expressed as mg/mL of heat-aggregated IgG-equivalents obtained from the calibration curve. The IL-1b serum levels were analyzed by ELISA and expressed in pg/mL. We used two-tailed Mann-Whitney U test and Spearman correlation for data analysis. Level of significance was set at p 0.05. Results: The mean values of CIC-C1q, CIC-C3d and IL-1b in the blood serum of patients with PTSD were significantly 1.7
P.4.b. Anxiety disorders and anxiolytics − Anxiety disorders (basic)
P.4.b.008 Beta-adrenoceptor stimulation by isoproterenol promotes olfactory fear conditioning in rats 1 Universidade E. Pavesi1 ° , N.S. Canteras2 , A.P. Carobrez3 . Federal de Santa Catarina, Dept. of Farmacologia, Florian´opolis, Brazil; 2 Universidade de S˜ao Paulo, Dept. of Anatomia, S˜ao Paulo, Brazil; 3 Universidade de Santa Catarina, Dept. of Farmacologia, Florian´opolis, Brazil
Purpose: Clinical studies have reported that beta-adrenoceptor agonists like isoproterenol (ISO), induced anxiogenic responses by sympathetic stimulation, and could promote panic attacks in humans. In rodents, beta-adrenoceptors within the dorsal premammillary nucleus (PMd) have been shown to mediate defensive responses toward predator odor [1]. PMd has also been shown to mediate the expression of conditioned fear responses to the shockpaired odor [2] and beta-adrenoceptor antagonist applied to the PMd reduced the defensive behavior elicited by the olfactory fear conditioning (OFC) stimulus [3]. It remains to be tested whether the beta-adrenoceptors activation within the PMd could support fear conditioning as an unconditioned stimulus (US) to induce the OFC. Methods: Seven days after male Wistar rats had received a guide cannula aimed at the PMd, they were submitted to the OFC protocol consisting of 2 phases: the acquisition (2 sessions) and the expression (3 sessions), spaced 24 hours each other. In Experiment 1, on day 1, rats were familiarized with the conditioning chamber. On the following day, they received microinjections (0.3ml) of PBS or ISO (10 or 40nmol) 5 min before the amylacetate (AA) exposure (CS1 -250 ml, 5%). The total exposure time to the AA was 3min and 20s or 10min. The OFC expression phase was set in an odor box comprising an open and an enclosed communicating compartment. The sessions were: familiarization to chamber (neutral odor); CS1 test (AA odor) and CS2 test (neutral odor). In Experiment 2, rats were divided to receive Atenolol (b1-antagonist, 40nmol) or PBS 5 min prior to conditioning session with ISO40 microinjection. In Experiment 3, the animals received intraperitoneal injections of either saline or nadolol (10 mg/Kg), a b-blocker that does not cross the blood-brain barrier, 30 min before the ISO40 conditioning session. During CS1 and CS2 tests, the percentage of time the rats spent near the odor source (%AT), and of time spent in a hidden compartment (%HT) were taken as an index of defensive behavior. Results: In Exp. 1, ANOVA repeated measure followed by Newman-Keuls revealed that ISO induced the acquisition of OFC. Subjects exposed to AA during 10min showed a significant decrease in the %AT (PBS; 30.1±3.4; ISO10; 10.6±1.9; ISO40; 9.2±1.5) and increased %HT (PBS; 37.5±4.4; ISO10; 76.3±4.6; ISO40; 78.5±3.0) during the CS1 session. The same profile of results was obtained during the CS2 session [PBS(%AT; 28.5±3.8; %HT; 36.1±6.1); ISO10 (%AT; 10.7±1.9; %HT; 72.1±4.0); ISO40 (%AT; 10.0±1.4; %HT; 73.6±2.0)]. In Exp 2, Atenolol prevented the ISO40 conditioning [CS1 (%AT; 31.6±3.8; %HT; 40.6±3.9); CS2 (%AT = 30.4±2.5; %HT = 38.3±4.0)]. In Exp. 3, the results failed to show any statistical difference between subjects that received systemic nadolol treatment before conditioning to ISO40. Conclusions: The present findings demonstrate that badrenergic activation in the PMd could function as an interoceptive-US, promoting a robust US-CS association. The anxiogenic effect of ISO was mainly due to b1-adrenoceptors
activation. Furthermore, the lack of systemic nadolol effect on ISO-OFC conditioning suggest an ascending PMd activation to prosencephalic areas. The results suggest the OFC paradigm as an experimental tool to test brain structures responsible to promote fear conditioning. Financial Supports: CNPq, CAPES, FAPESP, UFSC. References [1] Do Monte, F.H., Canteras, N.S., Fernandes, D., Assreuy, J., Carobrez, A.P., 2008 New perspectives on beta-adrenergic mediation of innate and learned fear responses to predator odor. The Journal of Neuroscience 28, 13296–13302. [2] Canteras, N.S., Kroon, J.A., Do-Monte, F.H., Pavesi, E., Carobrez, A.P., 2008 Sensing danger through the olfactory system: the role of the hypothalamic dorsal premammillary nucleus. Neuroscience Biobehavioral Reviews 32, 1228–1235. [3] Pavesi, E., Canteras, N.S., Carobrez, A.P., 2009 P.4.b.006 Atenolol impairs the acquisition and expression of olfactory fear conditioning in rats. European Neuropsychopharmacology 19, S599-S600.
P.4.b.009 Posttraumatic stress disorder and inflammation G. Mkrtchyan1 ° , L. Hovhannisyan1 , A. Boyajyan1 , M. Tadevosyan2 , A. Kalashyan2 , S. Sukiasian2 . 1 Institute of Molecular Biology of Armenian National Academy of Sciences, Laboratory of Macromolecular Complexes, Yerevan, Rep. of Armenia; 2 Ministry of Labour and Social Affairs of Armenia, Stress Center, Yerevan, Rep. of Armenia Background: Post-Traumatic Stress Disorder (PTSD) may develop following exposure to a traumatic event and is associated with debilitating physical and psychological health declines. Symptoms of PTSD include re-experiencing of the traumatic event through intrusive dreams or thoughts; physiologic arousal to stimuli that represent the trauma; numbing of feelings and avoidance of thoughts, feelings, people, and activities that symbolize the trauma. Several studies have reported immune function alterations in individuals with PTSD suggesting that low-grade inflammatory response is involved in PTSD pathogenesis on a chronic stage of the disease. However, the data are inconclusive, leading to an insufficient understanding of the role of inflammatory reactions in PTSD. Purpose: The aim of this study was to study some indicators of inflammation in PTSD-affected subjects and to perform correlation analyses between these parameters and clinical features of the disease. For this purpose we have examined 17 PTSD patients, combat veterans, diagnosed by application of the Clinical Administered PTSD Scale (CAPS). Age- and gender-matched 16 healthy subjects without any history of physical or sexual abuse or other major trauma, defined as being free of current or past psychiatric disorders served as a control group. Methods: Among the indicators of the inflammatory response, circulating immune complexes (CICs) and pro-inflammatory cytokine, IL-1b, were determined in the blood serum samples of patients and controls. CICs were measured using a C1q- and C3d-binding ELISA kit. The concentration of CICs was expressed as mg/mL of heat-aggregated IgG-equivalents obtained from the calibration curve. The IL-1b serum levels were analyzed by ELISA and expressed in pg/mL. We used two-tailed Mann-Whitney U test and Spearman correlation for data analysis. Level of significance was set at p 0.05. Results: The mean values of CIC-C1q, CIC-C3d and IL-1b in the blood serum of patients with PTSD were significantly 1.7