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S173 ANALYSIS OF SURAL NERVE IN ADULT RATS AFTER PAINFUL STIMULI IN NEONATAL PERIOD
POSTER SESSIONS / European Journal of Pain Supplements 5 (2011) 15–295
were 0.67±0.07 and 0.71±0.07 respectively. After converting to standard normal distribution for marked and unmarked SUV, the positive predictive value, negative predictive value, sensitivity and specificity to localize marked point were 89.7%, 87.1%, 86.7%, 90.0%, respectively Conclusions: This study showed the significant SUV difference between marked and unmarked area. Further study with severe pain group or a large number of samples is needed for clinical use of PET-CT. Disclosure: None declared
S171 GAMMA OSCILLATIONS ARE INVOLVED IN THE SENSORIMOTOR TRANSFORMATION OF PAIN E. Schulz1 *, L. Tiemann1 , V. Witkovsky2 , P. Schmidt1 , M. Ploner1 . 1 Department of Neurology, Technische Universit¨ at M¨ unchen, M¨ unchen, Germany; 2 Department of Theoretical Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovak Republic Background and Aims: The physical integrity of the individual critically depends on the perception of pain. Central to the protective function of pain are fast and effective behavioral responses to potentially harmful stimuli. Accordingly, pain drives the individual into a motor response aimed at achieving safety and promoting recovery. Methods: We investigated the neural mechanisms subserving the sensorimotor transformation of pain by using electroencephalography (EEG). In a simple reaction time experiment, brief painful stimuli were delivered to the left hand of healthy human subjects who responded as fast as possible with button presses of the right hand. Results: The execution of the task was associated with neuronal responses at theta, alpha/beta and gamma frequencies. Responses at all frequencies were temporally coupled to the painful stimuli as well as to the button presses. A topographical analysis of gamma and theta map series revealed brain states associated with sensory processing of pain as well as with motor responses to pain. Furthermore, we determined which neuronal responses predict the efficiency of the sensorimotor transformation process. We found that gamma responses which were temporally coupled to the painful stimuli – but not temporally coupled to the motor response – predicted response times. Conclusions: Our data indicate a contribution of gamma responses to the processing of pain as well as the initiation and execution of motor responses. Amplitudes of gamma responses are predictive for the speed of the transformation of a nociceptive event into a protective motor response. Disclosure: None declared
S172 HIND PAW GRIPPING ABILITY AND MUSCLE PERIMETER IN MALE AND FEMALE WISTAR RATS SUBMITTED TO PAINFUL STIMULATION IN NEONATAL PERIOD E.C. do Carmo, N.L.B. Machado, L.S. Sanada, V.P.S. Fazan *. Neurosciences and Behavioral Neurosciences, School of Medicine of Ribeir˜ ao Preto, Ribeir˜ ao Preto, Brazil Background and Aims: Previous studies revealed that Grip Strength Meter (GSM) assessment of gripping ability provides reliable quantitative measurements of motor function deficits in rats. This study evaluated muscle strength and perimeter of the hind paw in female and male Wistar rats, exposed to painful stimulation after birth. Methods: Sixty-two rats aged 180 days were separated into male pain group (n = 14); female pain group (n = 16); male control group (n = 17) and female control group (n = 15). The pain groups were stimulated with a needle on the right paw, twice a day for 15 days after birth. The control group was stimulated with a cotton swab on
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the right paw, twice a day for 15 days after birth. All animals were weighed and evaluated with a GSM. The hind paw was measured with a caliper rule associated with tape. Specific static tests were applied, and differences were considered significant when p < 0.05. Results: Body weight of the female groups was lower compared to ma Body weight of both pain groups were lower compared to the control groups as was the score when we analyzed the muscle strength with the GSM. The values of the hind paws perimeter of the pain groups were lower compared to the control groups. Conclusions: Nociceptive stimulation on neonatal period can influence the motor development, the muscle perimeter and the body weight both in male and female. Nociceptive stimulation on neonatal period does influence the motor development, the muscle perimeter and the body weight both in male and female. Disclosure: None declared
S173 ANALYSIS OF SURAL NERVE IN ADULT RATS AFTER PAINFUL STIMULI IN NEONATAL PERIOD L.S. Sanada, E.C. do Carmo, N.L.B. Machado, V.P.S. Fazan *. Neurosciences and Behavioral Neurosciences, School of Medicine of Ribeir˜ ao Preto, Ribeirao Preto, Brazil Background and Aims: The repetitive painful experiences in neonatal period can cause brain damage; however, there are few investigations about these consequences in peripheral nerves. We aimed to evaluate long term alterations in sural nerve due to painful stimulation in neonatal period. Methods: Wistar rats were followed for 180 days of life, and they were separated in 2 groups: 1. Control group (3 animals stimulated with cotton swab twice a day for 15 days, since they were born); 2. Pain group (3 animals stimulated with needle twice a day for 15 days, since they were born). Animals were evaluated by Von Frey Monofilament (VFM) and gait analysis (GA). After the animals completed 180 days of life, they were killed, the sural nerves were prepared for light microscopy and morphometry. Specific statistic tests were applied, and differences were considered significant when p < 0.05. Results: There was a significant difference between control and pain groups, when we compared VFM and GA. Despite of the sensori-motor assessment showed a significant difference between pain and control group, there were no differences in the morphology and morphometic parameters of sural nerves between groups. Conclusions: Pain stimuli in neonatal period were capable to alter the somatossensory development in young rats, however, it was not enough to modify the structure of sural nerve.pain stimuli in neonatal period were capable to alter the somatossensory development in young rats, however, it was not enough to modify the structure of sural nerve. Disclosure: None declared
S174 ELEVATED PLUS MAZE BEHAVIORAL INVESTIGATION IN ADULT RATS AFTER PAINFUL STIMULATION IN NEONATAL PERIOD N.B.L. Machado, L.S. Sanada, E.C. do Carmo, V.P.S. Fazan *. Neurosciences and Behavioral Neurosciences, School of Medicine of Ribeir˜ ao Preto, Ribeirao Preto, Brazil Background and Aims: New-born are often exposed to several painful procedures that may result in behavior changes. The aim of the present study was to investigate if painful stimulation during neonate period could trigger behavioral changes in adult rats. Methods: Twenty-four Wistar rats with 180 days of life were separated in 4 groups: pain male group (N = 6), pain female group (N = 6), control male group (N = 6) and control female group (N = 6). The pain group was stimulated, right after birth, with a needle on the right paw twice a day for 15 days. The control group was
were 0.67±0.07 and 0.71±0.07 respectively. After converting to standard normal distribution for marked and unmarked SUV, the positive predictive value, negative predictive value, sensitivity and specificity to localize marked point were 89.7%, 87.1%, 86.7%, 90.0%, respectively Conclusions: This study showed the significant SUV difference between marked and unmarked area. Further study with severe pain group or a large number of samples is needed for clinical use of PET-CT. Disclosure: None declared
S171 GAMMA OSCILLATIONS ARE INVOLVED IN THE SENSORIMOTOR TRANSFORMATION OF PAIN E. Schulz1 *, L. Tiemann1 , V. Witkovsky2 , P. Schmidt1 , M. Ploner1 . 1 Department of Neurology, Technische Universit¨ at M¨ unchen, M¨ unchen, Germany; 2 Department of Theoretical Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovak Republic Background and Aims: The physical integrity of the individual critically depends on the perception of pain. Central to the protective function of pain are fast and effective behavioral responses to potentially harmful stimuli. Accordingly, pain drives the individual into a motor response aimed at achieving safety and promoting recovery. Methods: We investigated the neural mechanisms subserving the sensorimotor transformation of pain by using electroencephalography (EEG). In a simple reaction time experiment, brief painful stimuli were delivered to the left hand of healthy human subjects who responded as fast as possible with button presses of the right hand. Results: The execution of the task was associated with neuronal responses at theta, alpha/beta and gamma frequencies. Responses at all frequencies were temporally coupled to the painful stimuli as well as to the button presses. A topographical analysis of gamma and theta map series revealed brain states associated with sensory processing of pain as well as with motor responses to pain. Furthermore, we determined which neuronal responses predict the efficiency of the sensorimotor transformation process. We found that gamma responses which were temporally coupled to the painful stimuli – but not temporally coupled to the motor response – predicted response times. Conclusions: Our data indicate a contribution of gamma responses to the processing of pain as well as the initiation and execution of motor responses. Amplitudes of gamma responses are predictive for the speed of the transformation of a nociceptive event into a protective motor response. Disclosure: None declared
S172 HIND PAW GRIPPING ABILITY AND MUSCLE PERIMETER IN MALE AND FEMALE WISTAR RATS SUBMITTED TO PAINFUL STIMULATION IN NEONATAL PERIOD E.C. do Carmo, N.L.B. Machado, L.S. Sanada, V.P.S. Fazan *. Neurosciences and Behavioral Neurosciences, School of Medicine of Ribeir˜ ao Preto, Ribeir˜ ao Preto, Brazil Background and Aims: Previous studies revealed that Grip Strength Meter (GSM) assessment of gripping ability provides reliable quantitative measurements of motor function deficits in rats. This study evaluated muscle strength and perimeter of the hind paw in female and male Wistar rats, exposed to painful stimulation after birth. Methods: Sixty-two rats aged 180 days were separated into male pain group (n = 14); female pain group (n = 16); male control group (n = 17) and female control group (n = 15). The pain groups were stimulated with a needle on the right paw, twice a day for 15 days after birth. The control group was stimulated with a cotton swab on
217
the right paw, twice a day for 15 days after birth. All animals were weighed and evaluated with a GSM. The hind paw was measured with a caliper rule associated with tape. Specific static tests were applied, and differences were considered significant when p < 0.05. Results: Body weight of the female groups was lower compared to ma Body weight of both pain groups were lower compared to the control groups as was the score when we analyzed the muscle strength with the GSM. The values of the hind paws perimeter of the pain groups were lower compared to the control groups. Conclusions: Nociceptive stimulation on neonatal period can influence the motor development, the muscle perimeter and the body weight both in male and female. Nociceptive stimulation on neonatal period does influence the motor development, the muscle perimeter and the body weight both in male and female. Disclosure: None declared
S173 ANALYSIS OF SURAL NERVE IN ADULT RATS AFTER PAINFUL STIMULI IN NEONATAL PERIOD L.S. Sanada, E.C. do Carmo, N.L.B. Machado, V.P.S. Fazan *. Neurosciences and Behavioral Neurosciences, School of Medicine of Ribeir˜ ao Preto, Ribeirao Preto, Brazil Background and Aims: The repetitive painful experiences in neonatal period can cause brain damage; however, there are few investigations about these consequences in peripheral nerves. We aimed to evaluate long term alterations in sural nerve due to painful stimulation in neonatal period. Methods: Wistar rats were followed for 180 days of life, and they were separated in 2 groups: 1. Control group (3 animals stimulated with cotton swab twice a day for 15 days, since they were born); 2. Pain group (3 animals stimulated with needle twice a day for 15 days, since they were born). Animals were evaluated by Von Frey Monofilament (VFM) and gait analysis (GA). After the animals completed 180 days of life, they were killed, the sural nerves were prepared for light microscopy and morphometry. Specific statistic tests were applied, and differences were considered significant when p < 0.05. Results: There was a significant difference between control and pain groups, when we compared VFM and GA. Despite of the sensori-motor assessment showed a significant difference between pain and control group, there were no differences in the morphology and morphometic parameters of sural nerves between groups. Conclusions: Pain stimuli in neonatal period were capable to alter the somatossensory development in young rats, however, it was not enough to modify the structure of sural nerve.pain stimuli in neonatal period were capable to alter the somatossensory development in young rats, however, it was not enough to modify the structure of sural nerve. Disclosure: None declared
S174 ELEVATED PLUS MAZE BEHAVIORAL INVESTIGATION IN ADULT RATS AFTER PAINFUL STIMULATION IN NEONATAL PERIOD N.B.L. Machado, L.S. Sanada, E.C. do Carmo, V.P.S. Fazan *. Neurosciences and Behavioral Neurosciences, School of Medicine of Ribeir˜ ao Preto, Ribeirao Preto, Brazil Background and Aims: New-born are often exposed to several painful procedures that may result in behavior changes. The aim of the present study was to investigate if painful stimulation during neonate period could trigger behavioral changes in adult rats. Methods: Twenty-four Wistar rats with 180 days of life were separated in 4 groups: pain male group (N = 6), pain female group (N = 6), control male group (N = 6) and control female group (N = 6). The pain group was stimulated, right after birth, with a needle on the right paw twice a day for 15 days. The control group was