- Email: [email protected]
Characterization of CREB phosphorylation induced by serotonin (5-HT) in cultured cortical neurons of mice
S84
Abstracts
whether this interaction depends on the ligand binding to the receptor. In consequence, p75 interacts with PIR-B regardless of with or without MAG-Fc treatment in cerebellar glanule neurons. Downstream of this receptor complex, SHP is associated with the effector of MAG-Fc. Our results suggest that p75 associates with PIR-B to mediate the action of myelin-associated neurite growth inhibition. doi:10.1016/j.neures.2009.09.325
P1-b35 Diacylglycerol kinase  promotes dendritic outgrowth and spine maturation in developing hippocampal neurons Yasukazu Hozumi, Kaoru Goto Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata, Japan Diacylglycerol kinase (DGK) is involved in the intracellular signal transduction as a regulator of two second messengers, diacylglycerol and phosphatidic acid. Recently, we have reported that DGK is expressed in medium spiny neurons of the striatum and is highly concentrated at the perisynapse of dendritic spines. Furthermore, one of the transcripts derived from the human DGK locus is annotated in GenBank as being differentially expressed in bipolar disorder patients. However, it remains elusive how DGK is implicated in pathophysiological role in neurons at the cellular level. In the present study, we investigated a potential involvement of DGK in spine morphogenesis in transfected hippocampal neurons. We suggest that DGK is involved in the molecular machinery of dendrite outgrowth and spinogenesis through its kinase activity. doi:10.1016/j.neures.2009.09.326
P1-b36 Dendritic shape and EPSP conduction of cortical nonpyramidal cells Yoshiyuki Kubota 1 , Fuyuki Karube 1 , Masaki Nomura 2 , Toshio Aoyagi 2 , Yasuo Kawaguchi 1 1
Div. Cerebral Circuitry, NIPS, Okazaki, Japan; Informatics, Kyoto, Japan
2
Kyoto University Grad. Sch.
Dendritic morphology greatly influences neuronal synaptic signal integration. Dendritic arborization patterns and local dimensions were analyzed in four subtypes of neocortical GABAergic cells. The dendritic local size parameters were obtained by 3-dimensional reconstruction of serial ultrathin sections. The cross-sectional areas of dendrites were well correlated with the summated dendritic length between the measured point and end tips. At branch points, the cross-sectional area of the mother dendrite was almost equal to the sum of those of the two daughter branches. Following these morphological rules, we constructed computational model neurons and analyzed the passive conduction property of EPSP along the dendrite. The simulation studies revealed that the most synaptic excitatory inputs on various dendrite locations generate similar somatic depolarizations. These results suggest the 3-dimensional dendritic shape is formed to increase the equality among various excitatory inputs distributed along the dendrites. doi:10.1016/j.neures.2009.09.327
P1-c01 The effects of a novel anti-Parkisonian drug on dopamine syshesis and vesicular dopamine uptake in dopaminergic cells Taisuke Yamagiwa, Shintaro Yasui, Hiroko Inoue Graduate School of Advanced Science and Engineering, Waseda Univeersity, Tokyo, Japan An antiepileptic drug has recently been shown to exert beneficial effects in Parkinson’s disease. However, the mechanism of the anti-Parkinsonian effects of the drug remains unclear. In this study, we attempted to elucidate the effects of the antiepileptic drug on dopamine synthesis and vesicular dopamine storage in dopaminergic cells. We examined the effects of the drug on tyrosine hydroxylase (TH), the rate limiting enzyme in dopamine synthesis, in PC12 cells. The enzyme activity was increased by the treatment of the drug, although the expression level of TH was not altered. We also examined the effects of the drug on cytosolic dopamine uptake into secretory vesicles via vesicular monoamine transporter 2 in PC12 and SH-SY5Y cells. doi:10.1016/j.neures.2009.09.328
P1-c02 Regulation of alpha CaMKII-activation in living cells Kenichi Kato, Satoshi Kida Dep. of Bioscience, Tokyo Univ. of Agriculture, Tokyo, Japan
Increase in intracellular Ca2+ concentration has been shown to lead to the activation of ␣CaMKII thorough the interaction with Ca2+ /CaM (CaM-interaction) followed by the conformational change of this kinase. To understand the regulation of ␣CaMKII activity in vivo, we have investigated CaM-interaction and conformational change of ␣CaMKII in living cells using FRET. In this study, we compared dynamics of ␣CaMKII activation in several types of cells. In HeLa cells and SH-SY5Y cells, long-term increase in Ca2+ induced continuous CaM-interaction and conformational change of ␣CaMKII, while short-term increase induced only transient CaM-interaction but maintained the conformational change of ␣CaMKII even after the dissociation of CaM. Interestingly, we observed similar changes of CaM-interaction and conformational changes of ␣CaMKII in cortical neurons in response to long or short-term application, respectively, of NMDA. These findings suggest that differences of intracellular Ca2+ dynamics lead to distinct patterns of ␣CaMKII activation. doi:10.1016/j.neures.2009.09.329
P1-c03 Estimation of intracellular calcium ion concentration and Ca influx by nonlinear state space modeling Takamasa Tsunoda 1 , Toshiaki Omori 2,3 , Hiroyoshi Miyakawa 4 , Masato Okada 2,3 , Toru Aonishi 1,3 1
Tokyo Tech., Japan; 2 Univ. of Tokyo, Japan; Univ. of Pharm, Japan
3
RIKEN BSI, Japan;
4
Tokyo
Calcium imaging method has superior ability in recording of spatial-temporal variations of ion concentrations. However, it has two major problems. First, the imaging signals are too noisy. Second, the observation data are the fluorescent intensities of Ca2+ indicator dyes that are only indirect information about the Ca2+ concentration. We devised an algorithm based on a nonlinear state-space approach for estimating the Ca2+ concentration and the Ca influx from the noisy fluorescent signals. First, we made a state-space model for the fluorescent signal series including Ca kinetics and a noisy fluorescent intensity pickup process. Then, we derived recursive update equations for one-step-ahead prediction, filtering and smoothing, and devised an EM (Expectation Maximization) algorithm for determining the model parameters. By using our algorithm, it is possible to estimate the temporal variations in cytoplasmic Ca2+ concentration and total Ca influx through cellular and endoplasmic reticulum (ER) membranes. doi:10.1016/j.neures.2009.09.330
P1-c04 Characterization of CREB phosphorylation induced by serotonin (5-HT) in cultured cortical neurons of mice Jiro Kasahara, Kohji Ohmura, Kohji Fukunaga Dept. Pharmacol., Grad. Sch. Pharmaceu. Sci., Tohoku Univ., Sendai, Japan Most of the antidepressants (ADs) have an inhibitory effect on monoamine transporters such as serotonin (5-HT) and/or noradrenaline transporters. In addition to this effect, long-term plastic changes of gene expressions are thought to be involved in the mechanisms of action of ADs. Combined together, monoaminetriggered signals may be transduced into nuclei of neurons, although its molecular and pharmacological properties are not well characterized yet. In this study, we characterized 5-HT-induced CREB phosphorylation in cultured cortical neurons derived from C57BL/6 mice. Compared to the strong and transient increase of glutamateinduced CREB phosphorylation, 5-HT induced weaker and prolonged increase of CREB phosphorylation. We further examined the protein kinases involved in its mechanism, and it was suggested that CaMKIV and MAPK were possible candidates. doi:10.1016/j.neures.2009.09.331
P1-c05 Modulation of feed-forward inhibition on CA1 pyramidal cells by patterned synaptic input probed with voltage-sensitive dye imaging in rat hippocampal slices Takashi Tominaga 1,2 , Yoko Tominaga 1 1
Dept. Neurophysiol., Tokushima Bunri Univ., Kagawa, Japan; Wako, Japan
2
RIKEN BSI,
Patterned input of inhibitory synapses on a cell plays an important role in neuronal function. However, inhibitory action is difficult to evaluate because of its multiple ways of regulation. Here we report an evaluation method of inhibitory action on membrane potential dynamics with voltage-sensitive dye (VSD) optical recording methods. Using this method we compared difference of laminar specific response upon stimulation to strata radiatum (SR), oriens (SO), and lacunosum-moleculare (SLM). The SR stimulation and SLM stimulation showed significant feed-forward components in perisomatic and distal apical dendritic regions. This was consistent with the IPSC components under whole cell clamp condition. We further evaluated modulation of the feed-forward inhibition by combination of temporal and combina-
Abstracts
whether this interaction depends on the ligand binding to the receptor. In consequence, p75 interacts with PIR-B regardless of with or without MAG-Fc treatment in cerebellar glanule neurons. Downstream of this receptor complex, SHP is associated with the effector of MAG-Fc. Our results suggest that p75 associates with PIR-B to mediate the action of myelin-associated neurite growth inhibition. doi:10.1016/j.neures.2009.09.325
P1-b35 Diacylglycerol kinase  promotes dendritic outgrowth and spine maturation in developing hippocampal neurons Yasukazu Hozumi, Kaoru Goto Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata, Japan Diacylglycerol kinase (DGK) is involved in the intracellular signal transduction as a regulator of two second messengers, diacylglycerol and phosphatidic acid. Recently, we have reported that DGK is expressed in medium spiny neurons of the striatum and is highly concentrated at the perisynapse of dendritic spines. Furthermore, one of the transcripts derived from the human DGK locus is annotated in GenBank as being differentially expressed in bipolar disorder patients. However, it remains elusive how DGK is implicated in pathophysiological role in neurons at the cellular level. In the present study, we investigated a potential involvement of DGK in spine morphogenesis in transfected hippocampal neurons. We suggest that DGK is involved in the molecular machinery of dendrite outgrowth and spinogenesis through its kinase activity. doi:10.1016/j.neures.2009.09.326
P1-b36 Dendritic shape and EPSP conduction of cortical nonpyramidal cells Yoshiyuki Kubota 1 , Fuyuki Karube 1 , Masaki Nomura 2 , Toshio Aoyagi 2 , Yasuo Kawaguchi 1 1
Div. Cerebral Circuitry, NIPS, Okazaki, Japan; Informatics, Kyoto, Japan
2
Kyoto University Grad. Sch.
Dendritic morphology greatly influences neuronal synaptic signal integration. Dendritic arborization patterns and local dimensions were analyzed in four subtypes of neocortical GABAergic cells. The dendritic local size parameters were obtained by 3-dimensional reconstruction of serial ultrathin sections. The cross-sectional areas of dendrites were well correlated with the summated dendritic length between the measured point and end tips. At branch points, the cross-sectional area of the mother dendrite was almost equal to the sum of those of the two daughter branches. Following these morphological rules, we constructed computational model neurons and analyzed the passive conduction property of EPSP along the dendrite. The simulation studies revealed that the most synaptic excitatory inputs on various dendrite locations generate similar somatic depolarizations. These results suggest the 3-dimensional dendritic shape is formed to increase the equality among various excitatory inputs distributed along the dendrites. doi:10.1016/j.neures.2009.09.327
P1-c01 The effects of a novel anti-Parkisonian drug on dopamine syshesis and vesicular dopamine uptake in dopaminergic cells Taisuke Yamagiwa, Shintaro Yasui, Hiroko Inoue Graduate School of Advanced Science and Engineering, Waseda Univeersity, Tokyo, Japan An antiepileptic drug has recently been shown to exert beneficial effects in Parkinson’s disease. However, the mechanism of the anti-Parkinsonian effects of the drug remains unclear. In this study, we attempted to elucidate the effects of the antiepileptic drug on dopamine synthesis and vesicular dopamine storage in dopaminergic cells. We examined the effects of the drug on tyrosine hydroxylase (TH), the rate limiting enzyme in dopamine synthesis, in PC12 cells. The enzyme activity was increased by the treatment of the drug, although the expression level of TH was not altered. We also examined the effects of the drug on cytosolic dopamine uptake into secretory vesicles via vesicular monoamine transporter 2 in PC12 and SH-SY5Y cells. doi:10.1016/j.neures.2009.09.328
P1-c02 Regulation of alpha CaMKII-activation in living cells Kenichi Kato, Satoshi Kida Dep. of Bioscience, Tokyo Univ. of Agriculture, Tokyo, Japan
Increase in intracellular Ca2+ concentration has been shown to lead to the activation of ␣CaMKII thorough the interaction with Ca2+ /CaM (CaM-interaction) followed by the conformational change of this kinase. To understand the regulation of ␣CaMKII activity in vivo, we have investigated CaM-interaction and conformational change of ␣CaMKII in living cells using FRET. In this study, we compared dynamics of ␣CaMKII activation in several types of cells. In HeLa cells and SH-SY5Y cells, long-term increase in Ca2+ induced continuous CaM-interaction and conformational change of ␣CaMKII, while short-term increase induced only transient CaM-interaction but maintained the conformational change of ␣CaMKII even after the dissociation of CaM. Interestingly, we observed similar changes of CaM-interaction and conformational changes of ␣CaMKII in cortical neurons in response to long or short-term application, respectively, of NMDA. These findings suggest that differences of intracellular Ca2+ dynamics lead to distinct patterns of ␣CaMKII activation. doi:10.1016/j.neures.2009.09.329
P1-c03 Estimation of intracellular calcium ion concentration and Ca influx by nonlinear state space modeling Takamasa Tsunoda 1 , Toshiaki Omori 2,3 , Hiroyoshi Miyakawa 4 , Masato Okada 2,3 , Toru Aonishi 1,3 1
Tokyo Tech., Japan; 2 Univ. of Tokyo, Japan; Univ. of Pharm, Japan
3
RIKEN BSI, Japan;
4
Tokyo
Calcium imaging method has superior ability in recording of spatial-temporal variations of ion concentrations. However, it has two major problems. First, the imaging signals are too noisy. Second, the observation data are the fluorescent intensities of Ca2+ indicator dyes that are only indirect information about the Ca2+ concentration. We devised an algorithm based on a nonlinear state-space approach for estimating the Ca2+ concentration and the Ca influx from the noisy fluorescent signals. First, we made a state-space model for the fluorescent signal series including Ca kinetics and a noisy fluorescent intensity pickup process. Then, we derived recursive update equations for one-step-ahead prediction, filtering and smoothing, and devised an EM (Expectation Maximization) algorithm for determining the model parameters. By using our algorithm, it is possible to estimate the temporal variations in cytoplasmic Ca2+ concentration and total Ca influx through cellular and endoplasmic reticulum (ER) membranes. doi:10.1016/j.neures.2009.09.330
P1-c04 Characterization of CREB phosphorylation induced by serotonin (5-HT) in cultured cortical neurons of mice Jiro Kasahara, Kohji Ohmura, Kohji Fukunaga Dept. Pharmacol., Grad. Sch. Pharmaceu. Sci., Tohoku Univ., Sendai, Japan Most of the antidepressants (ADs) have an inhibitory effect on monoamine transporters such as serotonin (5-HT) and/or noradrenaline transporters. In addition to this effect, long-term plastic changes of gene expressions are thought to be involved in the mechanisms of action of ADs. Combined together, monoaminetriggered signals may be transduced into nuclei of neurons, although its molecular and pharmacological properties are not well characterized yet. In this study, we characterized 5-HT-induced CREB phosphorylation in cultured cortical neurons derived from C57BL/6 mice. Compared to the strong and transient increase of glutamateinduced CREB phosphorylation, 5-HT induced weaker and prolonged increase of CREB phosphorylation. We further examined the protein kinases involved in its mechanism, and it was suggested that CaMKIV and MAPK were possible candidates. doi:10.1016/j.neures.2009.09.331
P1-c05 Modulation of feed-forward inhibition on CA1 pyramidal cells by patterned synaptic input probed with voltage-sensitive dye imaging in rat hippocampal slices Takashi Tominaga 1,2 , Yoko Tominaga 1 1
Dept. Neurophysiol., Tokushima Bunri Univ., Kagawa, Japan; Wako, Japan
2
RIKEN BSI,
Patterned input of inhibitory synapses on a cell plays an important role in neuronal function. However, inhibitory action is difficult to evaluate because of its multiple ways of regulation. Here we report an evaluation method of inhibitory action on membrane potential dynamics with voltage-sensitive dye (VSD) optical recording methods. Using this method we compared difference of laminar specific response upon stimulation to strata radiatum (SR), oriens (SO), and lacunosum-moleculare (SLM). The SR stimulation and SLM stimulation showed significant feed-forward components in perisomatic and distal apical dendritic regions. This was consistent with the IPSC components under whole cell clamp condition. We further evaluated modulation of the feed-forward inhibition by combination of temporal and combina-