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Occlusal disharmony attenuates glucocorticoid negative feedback in aged SAMP8 mice
S186
Abstracts
P2-m02 Long-lasting toothless condition progresses aging processes in the hippocampus Mitsuo Iinuma 1 , Chika Kurata 1 , Yukiko Ichihashi 1 , Yasuo Tamura 1 , Kin-ya Kubo 2 , Minoru Onozuka 3 1 3
2 Dent,Asahi Univ, Gifu, Japan; Oral Anat,Asahi Univ,Gifu, Japan; DepartmentPhysiol,Kanagawa Dent,Kanagawa, Japan
In order to assess whether toothless (extracting the upper molar teeth) at an early period after eruption of teeth (early toothless) exerts greater effects on hippocampal aging processes than late toothless, morphological and behavioral studies were done in the SAMP8 mice. Not only early toothless enhanced age-dependent decline in learning ability in a water maze test, but also in more decreased the number of hippocampal neurons than those in the age-matched control condition. However, the effects of late toothless was not significant, when compared with those in the control condition. The data suggest that a long-lasting toothless condition may result in progressing aging processes in the hippocampus. doi:10.1016/j.neures.2009.09.997
P2-m03 Occlusal disharmony attenuates glucocorticoid negative feedback in aged SAMP8 mice Kurata 1 , Mitsuo Iinuma 1 , Yasuo Yukiko Ichihashi 1 , Chika Tamura 1 , Kin-ya Kubo 2 , Minoru Onozuka 3 1
Dept Pediatric Dent,Asahi Univ,Gifu, Japan; 2 Oral Anat,Asahi Univ,Gifu, Japan; 3 DepartmentPhysiol,Kanagawa Dent,Kanagawa, Japan
To evaluate the mechanism underlying impaired cognitive function due to occlusal disharmony, we examined the effect of the bite-raised condition on spatial performance and hippocampal expression of glucocorticoid receptors (GR) and GRmRNA in aged SAMP8 mice. Learning ability in the water maze test was significantly impaired in aged bite-raised mice compared with that in age-matched control mice. Also, immunohistochemical and in situ hybridization analysis showed that the biteraised condition enhanced age-related decreases in GR and GRmRNA expression in the hippocampus. Furthermore, GR and GRmRNA expression were significantly decreased in aged bite-raised mice compared to that in age-matched control mice. These findings suggest that the occlusal disharmony in the elderly may decrease GR and GRmRNA, coupling with impairment of the hypothalamic–pituitary–adrenal feedback inhibition. doi:10.1016/j.neures.2009.09.998
P2-m04 Occlusal disharmony reduces the activity of catecholaminergic system Hidekazu Miyake 1 , Tasuku Katayama 1 , Daisuke Mori 1 , Shu Fujiwara 1 , Kin-ya Kubo 5 , Terumi Takeuchi 2 , Yoko Hasegawa 2 , Shinichi Toyota 2 , Keiki Yamada 3 , Minoru Onozuka 4 , N. Karasawa 2 1
Department Prosthodontics, Asahi University Sch. Dent., Gifu, Japan; 2 Seijoh University Graduate School. Health Care Studies, Japan; 3 Fujita Health University Sch. Health Sci., Japan; 4 Department Physiol. and Neurosci., Kanagawa Dent. Coll., Japan; 5 Department Oral Anatomy, Asahi University Sch. Dent., Japan We evaluated the involvement of occlusal disharmony in the aged catecholaminergic system, assessing immunohistochemical changes in TH, GCH and 5-HT in the cerebral cortex, substantia nigra (SN), locus ceruleus (LC), caudate nucleus (CN), and nucleus raphe dorsalis (RD) in either bite-raised condition or molarless condition in the aged SAMP8 mice. In both conditions, TH immunoreactive fibrous densities were decreased in the cerebral cortex, but TH immunoreactivity was decreased only in the CN of the bite-raised mice. In addition, significant decreases in GCH immunoreactivities were seen in the SN and LC in the bite-raised and molarless condition. Furthermore, in the RD of bite-raiesd mice, 5-HT and GCH immunoreactivities were decreased. These results suggest that occlusal disharmony may cause a reduction in activities in the central catecholaminergic system.
P2-m05 Hyperlocomotion and elevated synaptic plasticity in the anterior cingulate cortex in mice after chronic restraint stress Hiroshi Ito 1 , Masatoshi Nagano 2 , Hidenori Suzuki 2 , Takayuki Murakoshi 1 Arts and Sciences, Univ of Tokyo, Tokyo, Japan; Med School, Tokyo, Japan
doi:10.1016/j.neures.2009.09.1000
P2-m06 Stress sensitivities in atopic dermatitis and other dermatological diseases as examined by platelet PBR Yurie Nakamoto 1 , Mio Kaga 1,2 , Satoki Kubota 2 , Tomoko Nakada 2 , Toshikazu Shinba 1 , Mitsunobu Yoshii 1 , Seiji Kawana 2 1
Div Psychobiology, Tokyo Inst Psychiatry, Tokyo, Japan; Nippon Med Sch, Tokyo, Japan
2
Dep Dermatology,
Many dermatological diseases become more serious under stressful conditions, but their relations to individual’s stress sensitivity are not well understood. To address this issue, we examined patients with dermatological diseases for their expression of peripheral-type benzodiazepine receptor (PBR) on platelets as a measure of individual’s sensitivity to stress. Patients with atopic dermatitis (AD) (24 males, 9 females) showed significantly higher densities of PBR in parallel with higher scores of the trait anxiety. In contrast, alopecia areata (AA) patients (20 males, 30 females) showed lower PBR densities, particularly in females, despite higher anxiety scores. The severity of AA, however, was significantly correlated with the PBR density. Psoriasis (42 males, 9 females) was apparently not related to the stress. The results suggest that both AD and AA patients are in a state of stress, whereas stress responses are impaired in female AA patients with unknown mechanisms. doi:10.1016/j.neures.2009.09.1001
P2-m07 Regular voluntary exercise enhances neuronal activation of serotonergic neurons during acute running Shinya Yanagita 1,2 , Seiichiro Amemiya 2 , Satoko Suzuki 2 , Natsuko Kubota 2 , Tomomi Otsuka 2 , Ichiro Kita 2 1
Facul Pharmacol, Tokyo Univ of Sci, Chiba, Japan; Sci, Tokyo metropolitan Univ, Tokyo, Japan
2
Dept Human health
Many studies have showed that acute exercise enhances neural activity of serotonergic systems, which have crucial role for antidepressant properties. Although regular voluntary exercise (V-Ex) is known to improve mental health or mood, the effects of regular V-Ex on activation of the serotonin (5-HT) neurons in the dorsal raphe nucleus (DRN) during acute exercise are still unknown. The present study examined whether 4weeks V-Ex influences the neuronal activity of 5-HT neurons in the DRN during 2 types of acute running (i.e. spontaneous; SWR or forced wheel running; FWR) using immunohistrogical methods in rats. 4 weeks V-Ex significantly enhanced the activation of 5-HT neurons compared to sedentary controls in both SWR and FWR. The activation of 5-HT neurons in SWR was significantly higher than that of FWR. These results suggest that regular V-Ex could progress antidepressant properties of acute exercise via enhancing neuronal activation of 5-HT neurons. doi:10.1016/j.neures.2009.09.1002
P2-m08 Significant gender difference in histamine H1 receptors in the human brain Kazuhiko Yanai 1,2 , Manabu Tashiro 2 , Motohisa Kato 1 , Masahiko Yoshizawa 3 , Dongying Zhang 1 , Shin Fukudo 3 1
doi:10.1016/j.neures.2009.09.999
1
We investigated the effects of chronic stress on behaviors and synaptic function in the anterior cingulate cortex in mice. Four-weeks-old mice experienced chronic restraint stress (CRS) over a period of 7 days and were then subjected to behavioral tests. CRS mice, compared with controls, showed hyperactivity by the open field test, without showing anxiety-like behavior in the light-dark choice test, and displayed a decrease in freezing behavior in the fear conditioning test. Field excitatory postsynaptic potential (fEPSP) recorded in layer II/III of the ACC in vitro revealed that paired-pulse ratio of fEPSP was larger in CRS mice than that in controls, whereas this change was not observed in the presence of a GABAA receptor antagonist. Longterm potentiation and long-term depression of fEPSP were enhanced in CRS mice. These results suggest that CRS induced facilitation of synaptic plasticity possibly through disinhibition of GABAA receptor function in the ACC, which may underlie behavioral changes of hyperactivity.
2
Dep pharmacol, Nippon
Tohoku University Grad. Sch. of Med., Sendai, Japan; 2 Div. Nucl. Med., Cyclotron RI Center, Tohoku University, Japan; 3 Department Behav. Med., Tohoku University Grad. Sch. Med., Japan
Neuronal histamine is involved in many functions as a neurotransmitter. The aim of this study is to investigate the gender difference in H1 receptor in the human brain using PET and [11 C]doxepin. The H1 receptor was measured in 12 male and 12 female healthy volunteers. We calculated the binding potential (BP) of [11 C]doxepin in each brain region using the cerebellum as a reference. The BPs in female subjects were higher than those in male subjects in most regions of cortex, especially in the medial
Abstracts
P2-m02 Long-lasting toothless condition progresses aging processes in the hippocampus Mitsuo Iinuma 1 , Chika Kurata 1 , Yukiko Ichihashi 1 , Yasuo Tamura 1 , Kin-ya Kubo 2 , Minoru Onozuka 3 1 3
2 Dent,Asahi Univ, Gifu, Japan; Oral Anat,Asahi Univ,Gifu, Japan; DepartmentPhysiol,Kanagawa Dent,Kanagawa, Japan
In order to assess whether toothless (extracting the upper molar teeth) at an early period after eruption of teeth (early toothless) exerts greater effects on hippocampal aging processes than late toothless, morphological and behavioral studies were done in the SAMP8 mice. Not only early toothless enhanced age-dependent decline in learning ability in a water maze test, but also in more decreased the number of hippocampal neurons than those in the age-matched control condition. However, the effects of late toothless was not significant, when compared with those in the control condition. The data suggest that a long-lasting toothless condition may result in progressing aging processes in the hippocampus. doi:10.1016/j.neures.2009.09.997
P2-m03 Occlusal disharmony attenuates glucocorticoid negative feedback in aged SAMP8 mice Kurata 1 , Mitsuo Iinuma 1 , Yasuo Yukiko Ichihashi 1 , Chika Tamura 1 , Kin-ya Kubo 2 , Minoru Onozuka 3 1
Dept Pediatric Dent,Asahi Univ,Gifu, Japan; 2 Oral Anat,Asahi Univ,Gifu, Japan; 3 DepartmentPhysiol,Kanagawa Dent,Kanagawa, Japan
To evaluate the mechanism underlying impaired cognitive function due to occlusal disharmony, we examined the effect of the bite-raised condition on spatial performance and hippocampal expression of glucocorticoid receptors (GR) and GRmRNA in aged SAMP8 mice. Learning ability in the water maze test was significantly impaired in aged bite-raised mice compared with that in age-matched control mice. Also, immunohistochemical and in situ hybridization analysis showed that the biteraised condition enhanced age-related decreases in GR and GRmRNA expression in the hippocampus. Furthermore, GR and GRmRNA expression were significantly decreased in aged bite-raised mice compared to that in age-matched control mice. These findings suggest that the occlusal disharmony in the elderly may decrease GR and GRmRNA, coupling with impairment of the hypothalamic–pituitary–adrenal feedback inhibition. doi:10.1016/j.neures.2009.09.998
P2-m04 Occlusal disharmony reduces the activity of catecholaminergic system Hidekazu Miyake 1 , Tasuku Katayama 1 , Daisuke Mori 1 , Shu Fujiwara 1 , Kin-ya Kubo 5 , Terumi Takeuchi 2 , Yoko Hasegawa 2 , Shinichi Toyota 2 , Keiki Yamada 3 , Minoru Onozuka 4 , N. Karasawa 2 1
Department Prosthodontics, Asahi University Sch. Dent., Gifu, Japan; 2 Seijoh University Graduate School. Health Care Studies, Japan; 3 Fujita Health University Sch. Health Sci., Japan; 4 Department Physiol. and Neurosci., Kanagawa Dent. Coll., Japan; 5 Department Oral Anatomy, Asahi University Sch. Dent., Japan We evaluated the involvement of occlusal disharmony in the aged catecholaminergic system, assessing immunohistochemical changes in TH, GCH and 5-HT in the cerebral cortex, substantia nigra (SN), locus ceruleus (LC), caudate nucleus (CN), and nucleus raphe dorsalis (RD) in either bite-raised condition or molarless condition in the aged SAMP8 mice. In both conditions, TH immunoreactive fibrous densities were decreased in the cerebral cortex, but TH immunoreactivity was decreased only in the CN of the bite-raised mice. In addition, significant decreases in GCH immunoreactivities were seen in the SN and LC in the bite-raised and molarless condition. Furthermore, in the RD of bite-raiesd mice, 5-HT and GCH immunoreactivities were decreased. These results suggest that occlusal disharmony may cause a reduction in activities in the central catecholaminergic system.
P2-m05 Hyperlocomotion and elevated synaptic plasticity in the anterior cingulate cortex in mice after chronic restraint stress Hiroshi Ito 1 , Masatoshi Nagano 2 , Hidenori Suzuki 2 , Takayuki Murakoshi 1 Arts and Sciences, Univ of Tokyo, Tokyo, Japan; Med School, Tokyo, Japan
doi:10.1016/j.neures.2009.09.1000
P2-m06 Stress sensitivities in atopic dermatitis and other dermatological diseases as examined by platelet PBR Yurie Nakamoto 1 , Mio Kaga 1,2 , Satoki Kubota 2 , Tomoko Nakada 2 , Toshikazu Shinba 1 , Mitsunobu Yoshii 1 , Seiji Kawana 2 1
Div Psychobiology, Tokyo Inst Psychiatry, Tokyo, Japan; Nippon Med Sch, Tokyo, Japan
2
Dep Dermatology,
Many dermatological diseases become more serious under stressful conditions, but their relations to individual’s stress sensitivity are not well understood. To address this issue, we examined patients with dermatological diseases for their expression of peripheral-type benzodiazepine receptor (PBR) on platelets as a measure of individual’s sensitivity to stress. Patients with atopic dermatitis (AD) (24 males, 9 females) showed significantly higher densities of PBR in parallel with higher scores of the trait anxiety. In contrast, alopecia areata (AA) patients (20 males, 30 females) showed lower PBR densities, particularly in females, despite higher anxiety scores. The severity of AA, however, was significantly correlated with the PBR density. Psoriasis (42 males, 9 females) was apparently not related to the stress. The results suggest that both AD and AA patients are in a state of stress, whereas stress responses are impaired in female AA patients with unknown mechanisms. doi:10.1016/j.neures.2009.09.1001
P2-m07 Regular voluntary exercise enhances neuronal activation of serotonergic neurons during acute running Shinya Yanagita 1,2 , Seiichiro Amemiya 2 , Satoko Suzuki 2 , Natsuko Kubota 2 , Tomomi Otsuka 2 , Ichiro Kita 2 1
Facul Pharmacol, Tokyo Univ of Sci, Chiba, Japan; Sci, Tokyo metropolitan Univ, Tokyo, Japan
2
Dept Human health
Many studies have showed that acute exercise enhances neural activity of serotonergic systems, which have crucial role for antidepressant properties. Although regular voluntary exercise (V-Ex) is known to improve mental health or mood, the effects of regular V-Ex on activation of the serotonin (5-HT) neurons in the dorsal raphe nucleus (DRN) during acute exercise are still unknown. The present study examined whether 4weeks V-Ex influences the neuronal activity of 5-HT neurons in the DRN during 2 types of acute running (i.e. spontaneous; SWR or forced wheel running; FWR) using immunohistrogical methods in rats. 4 weeks V-Ex significantly enhanced the activation of 5-HT neurons compared to sedentary controls in both SWR and FWR. The activation of 5-HT neurons in SWR was significantly higher than that of FWR. These results suggest that regular V-Ex could progress antidepressant properties of acute exercise via enhancing neuronal activation of 5-HT neurons. doi:10.1016/j.neures.2009.09.1002
P2-m08 Significant gender difference in histamine H1 receptors in the human brain Kazuhiko Yanai 1,2 , Manabu Tashiro 2 , Motohisa Kato 1 , Masahiko Yoshizawa 3 , Dongying Zhang 1 , Shin Fukudo 3 1
doi:10.1016/j.neures.2009.09.999
1
We investigated the effects of chronic stress on behaviors and synaptic function in the anterior cingulate cortex in mice. Four-weeks-old mice experienced chronic restraint stress (CRS) over a period of 7 days and were then subjected to behavioral tests. CRS mice, compared with controls, showed hyperactivity by the open field test, without showing anxiety-like behavior in the light-dark choice test, and displayed a decrease in freezing behavior in the fear conditioning test. Field excitatory postsynaptic potential (fEPSP) recorded in layer II/III of the ACC in vitro revealed that paired-pulse ratio of fEPSP was larger in CRS mice than that in controls, whereas this change was not observed in the presence of a GABAA receptor antagonist. Longterm potentiation and long-term depression of fEPSP were enhanced in CRS mice. These results suggest that CRS induced facilitation of synaptic plasticity possibly through disinhibition of GABAA receptor function in the ACC, which may underlie behavioral changes of hyperactivity.
2
Dep pharmacol, Nippon
Tohoku University Grad. Sch. of Med., Sendai, Japan; 2 Div. Nucl. Med., Cyclotron RI Center, Tohoku University, Japan; 3 Department Behav. Med., Tohoku University Grad. Sch. Med., Japan
Neuronal histamine is involved in many functions as a neurotransmitter. The aim of this study is to investigate the gender difference in H1 receptor in the human brain using PET and [11 C]doxepin. The H1 receptor was measured in 12 male and 12 female healthy volunteers. We calculated the binding potential (BP) of [11 C]doxepin in each brain region using the cerebellum as a reference. The BPs in female subjects were higher than those in male subjects in most regions of cortex, especially in the medial