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Changes of amygdaloid neuronal responses after acquisition of conditioned taste aversion in rats
S254
FUNCTIONAL LOCALIZATION OF THE CENTRAL EXECUTE AND DIGIT SUB-LOOPES IN WORKING MEMORY. HIDEAKI FUJITA, SHUICHI MIURA AND IWAO KANNO, Department of Radiology and Nuclear Medicine, Research Institute of Brain and Blood Vesels, Akita, 6-10 Senshu-Kubota machi. Akita 010, Japan.
2333
We aimed to clarify a functional localization of working memory using positron emission We measured cerebral blood flow tomography and HZ”0 infusion autoradiography method. changes during digit learning test in twenty healthy subjects (age ranged 19-70, mean 43 y.0.). We found foci at the tegmental areas of the pons and midbrain, both anterior cinguli and supplementary motor areas and the left middle frontal gyrus. Increments of blood flow of these areas positively correlated with h the score of learning. These suggest that these areas This coresponded to the robust foci of the left motor area and execute the subvocal rehearses. Another foci obtained in the both angular gyri. This suggests that the foci right cerebellum.
functioned as digit processes which were subslave we clarified the functional In conclusion, important roles of the central execute system.
system of working memory. localization of working memory
and
the
CHANGES OF AMYGDALOID NEURONAL RESPONSES AFTER ACQUISITION OF CONDITIONED TASTE AVERSION IN RATS. YASOSI-IIMA YASUNOBU. TSUYOSHI SHIMURA mTAKASHI YAMAMOTO, Dept. Behav. Phvsiol. Fat. of Human Sciences, Osaka, Univ..Yamadaoka 1-2,Osaka. 560. Japan.
2334
It is reported that lesions of the amygdala disrupted acquisition of conditioned taste aversion (CTA). To clarity the role of amygdala in acquisition of CTA, we chronically recorded amygdaloid units in freely behaving rats. Before the conditioning procedure, we recorded amygdaloid unit activities to the intraoral infusion of saccharin and 4 basic taste stimuli as preconditioning controls. After voluntary licking of saccharin (the conditioned stimulus,CS) for 5 min, rats were injected with LiCl (0.15 M, 1% of body weight, ip) as the unconditioned stimulus (US). After an interval of 30 min from the conditioning procedure, we recorded neuronal activities and behavioral reactivities of rats to intraoral n&ions of CS and other tastants intermittently for 6-7 hr. From the first to the last test, most of the rats (8/l 1) showed aversive behavior, such as chin rubbing, only to the CS, but not to the other taste stimuli. The others (3/l 1) showed aversive behavior to any fluids at the first test, but after 2-3 hr they turned to express aversive behavior specifically to the CS. Six of 29 units recorded from the central and basolateral nuclei significantly changed their activities after the conditioning in comparison with preconditioning control levels. Four units maintained theii enhanced activities specifically to the CS throughout postconditioning tests from 30 min to 6 hr. Two units showed enhanced activities in responses to any fluids during the first 3 br, however the changed responses sustained only to the CS in the latter tests. These results suggest that the rapid alteration of amygdaloid neural activities is related to the behavioral changes after acquisition of CTA.
2335
LATENCY SHIFTS IN EVOKED BURSTS INDUCED BY TETANI IN CORTICAL CELL CULTURES. YASUHIKO JIMBOr, HUGH P. C. ROBINSON* AND AK10 KAWANA’, ‘NTT Basic wh Law3_1wa 2Phvsioloaical Laboratorv. Universitv of Cambridge. U. K..
243-01. Janan,
LTP has been widely studied as an increase in synaptic efficacy at specific synapses. The consequences of LTP for networkactivity, however, are less clear. Using a combination of whole cell recording and extracellular recording and stimulation by planar electrode array substrates, we studied the effects of tetanic stimulation on synchronized bursts in networks of cortical neurons. Cortical cells from 18 day rat embryos were dissociated and cultured on electrode array substrates. After 4 weeks in vitro, EPSCs were elicited by a test stimulus train (3 pulses of 0.2 ms duration, 1.8 V amplitude, separated by 2 ms, at a frequency of 0.1 Hz), and recorded by whole cell patch clamp using the perforated Nystatin patch technique. The external medium contained 10 mM Mg++ to suppress spontaneous activity and 0.1 mM picrotoxin to block inhibitory inputs. Under these conditions, bursts of action potentials could be elicited by almost each stimulus train. Tetanic stimulation consisting of 20 Hz, 1 s trains was then appIied every 5 seconds for 2 min. Following tetanic stimulation, the time difference between the test stimulation and burst generation at the recorded cell gradually shortened and stabilized. The probability of burst generation also increased. These effects lasted as long as the recording could be maintained (over 20 mins), suggesting that they follow from the expression of LTP in the network.
FUNCTIONAL LOCALIZATION OF THE CENTRAL EXECUTE AND DIGIT SUB-LOOPES IN WORKING MEMORY. HIDEAKI FUJITA, SHUICHI MIURA AND IWAO KANNO, Department of Radiology and Nuclear Medicine, Research Institute of Brain and Blood Vesels, Akita, 6-10 Senshu-Kubota machi. Akita 010, Japan.
2333
We aimed to clarify a functional localization of working memory using positron emission We measured cerebral blood flow tomography and HZ”0 infusion autoradiography method. changes during digit learning test in twenty healthy subjects (age ranged 19-70, mean 43 y.0.). We found foci at the tegmental areas of the pons and midbrain, both anterior cinguli and supplementary motor areas and the left middle frontal gyrus. Increments of blood flow of these areas positively correlated with h the score of learning. These suggest that these areas This coresponded to the robust foci of the left motor area and execute the subvocal rehearses. Another foci obtained in the both angular gyri. This suggests that the foci right cerebellum.
functioned as digit processes which were subslave we clarified the functional In conclusion, important roles of the central execute system.
system of working memory. localization of working memory
and
the
CHANGES OF AMYGDALOID NEURONAL RESPONSES AFTER ACQUISITION OF CONDITIONED TASTE AVERSION IN RATS. YASOSI-IIMA YASUNOBU. TSUYOSHI SHIMURA mTAKASHI YAMAMOTO, Dept. Behav. Phvsiol. Fat. of Human Sciences, Osaka, Univ..Yamadaoka 1-2,Osaka. 560. Japan.
2334
It is reported that lesions of the amygdala disrupted acquisition of conditioned taste aversion (CTA). To clarity the role of amygdala in acquisition of CTA, we chronically recorded amygdaloid units in freely behaving rats. Before the conditioning procedure, we recorded amygdaloid unit activities to the intraoral infusion of saccharin and 4 basic taste stimuli as preconditioning controls. After voluntary licking of saccharin (the conditioned stimulus,CS) for 5 min, rats were injected with LiCl (0.15 M, 1% of body weight, ip) as the unconditioned stimulus (US). After an interval of 30 min from the conditioning procedure, we recorded neuronal activities and behavioral reactivities of rats to intraoral n&ions of CS and other tastants intermittently for 6-7 hr. From the first to the last test, most of the rats (8/l 1) showed aversive behavior, such as chin rubbing, only to the CS, but not to the other taste stimuli. The others (3/l 1) showed aversive behavior to any fluids at the first test, but after 2-3 hr they turned to express aversive behavior specifically to the CS. Six of 29 units recorded from the central and basolateral nuclei significantly changed their activities after the conditioning in comparison with preconditioning control levels. Four units maintained theii enhanced activities specifically to the CS throughout postconditioning tests from 30 min to 6 hr. Two units showed enhanced activities in responses to any fluids during the first 3 br, however the changed responses sustained only to the CS in the latter tests. These results suggest that the rapid alteration of amygdaloid neural activities is related to the behavioral changes after acquisition of CTA.
2335
LATENCY SHIFTS IN EVOKED BURSTS INDUCED BY TETANI IN CORTICAL CELL CULTURES. YASUHIKO JIMBOr, HUGH P. C. ROBINSON* AND AK10 KAWANA’, ‘NTT Basic wh Law3_1wa 2Phvsioloaical Laboratorv. Universitv of Cambridge. U. K..
243-01. Janan,
LTP has been widely studied as an increase in synaptic efficacy at specific synapses. The consequences of LTP for networkactivity, however, are less clear. Using a combination of whole cell recording and extracellular recording and stimulation by planar electrode array substrates, we studied the effects of tetanic stimulation on synchronized bursts in networks of cortical neurons. Cortical cells from 18 day rat embryos were dissociated and cultured on electrode array substrates. After 4 weeks in vitro, EPSCs were elicited by a test stimulus train (3 pulses of 0.2 ms duration, 1.8 V amplitude, separated by 2 ms, at a frequency of 0.1 Hz), and recorded by whole cell patch clamp using the perforated Nystatin patch technique. The external medium contained 10 mM Mg++ to suppress spontaneous activity and 0.1 mM picrotoxin to block inhibitory inputs. Under these conditions, bursts of action potentials could be elicited by almost each stimulus train. Tetanic stimulation consisting of 20 Hz, 1 s trains was then appIied every 5 seconds for 2 min. Following tetanic stimulation, the time difference between the test stimulation and burst generation at the recorded cell gradually shortened and stabilized. The probability of burst generation also increased. These effects lasted as long as the recording could be maintained (over 20 mins), suggesting that they follow from the expression of LTP in the network.