Objectives: To investigate the potential role of GABAB Receptors (GABABRs) involved in the effect of Nourishing “Yin”-Removing “Fire” Chinese herb mixture (TCM) treatment on precocious puberty. Methods: Female Spr...Objectives: To investigate the potential role of GABAB Receptors (GABABRs) involved in the effect of Nourishing “Yin”-Removing “Fire” Chinese herb mixture (TCM) treatment on precocious puberty. Methods: Female Sprague-Dawley rats were randomly divided into four groups: normal (N), central precocious puberty (CPP) model (M), CPP fed with normal saline (S) and CPP fed with Nourishing “Yin”-Removing “Fire” Chinese herb mixture (TCM). Rats of postnatal day 5 were given a single subcutaneous injection of 240 μg danazol to establish CPP model rats. Rats of S and TCM groups were continuously administered with saline or nourishing “Yin”-removing “Fire” Chinese herb mixture since postnatal day 15. The expression of GABABRs was detected by means of real-time PCR and immunohistochemistry. Results: The expression of hypothalamic GnRH mRNA in M was significantly increased on the day of pre-puberty when compared with that of N (P < 0.01). On the day of onset-puberty, LH levels were higher in M than those in N (P < 0.01), while the serum E2 and LH levels of TCM decreased when compared with those of M (P <sub>B1</sub> receptor (GABABR1) immunoreactive cells in the arcuate nucleus (ARN) was decreased in M when compared with that of N (P < 0.05) and increased in TCM compared with that of M (P < 0.05);simultaneously, the expression of GABABR1 mRNA in hypothalamus was significantly decreased in M when compared with that of N (P < 0.01) and increased in TCM compared with that of M (P < 0.01). On the day of onset-puberty, the number of GABABR1 immunoreactive cells in medial septum (MS) was decreased in M compared with that in N (P < 0.05) and increased in TCM comparing with that of M (P < 0.05);meanwhile, the mRNA expression of GABABR1 in hypothalamus was decreased in M compared with that in N (P <sub>B2</sub> receptor (GABABR2) immunoreactive cells in the ARN, MS and diagnonal band of broca (DBB) were decreased in M when compared with those of N (P < 0.05) and increased in TCM compared with those of M (P < 0.05) on the day of onset-puberty. At the same time, the mRNA expression of GABABR2 was significantly decreased in M compared with that of N (P < 0.01). Conclusions: These results indicated that the GABABRs might involve in the curative effect of Nourishing “Yin”-Removing “Fire” Chinese herbal mixture on CPP rats.展开更多
γ-amidobutyric acid (GABA) is a major inhibitory neurotransmitter in the central nervous system and mediates fast synaptic inhibition through GABAA and GABAC
BACKGROUND： An amino acid imbalance has been considered to be responsible for epilepsy pathogenesis. Gamma-aminobutyric acid-B receptor （GABABR） inhibits voltage-sensitive calcium ion channels and GABA or glutamic ...BACKGROUND： An amino acid imbalance has been considered to be responsible for epilepsy pathogenesis. Gamma-aminobutyric acid-B receptor （GABABR） inhibits voltage-sensitive calcium ion channels and GABA or glutamic acid （Glu） neurotransmitter release, which promotes or inhibits onset and development of epilepsy. OBJECTIVE： To explore the effect of baclofen on GBRla and GBR2 mRNA expression in the hippocampus of epileptic rats following kainic acid （KA） induction, and to study the adaptability of GABABR subunits. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment based on molecular biology was performed at the Laboratory Research Center of Second Hospital Affiliated to Soochow University from November 2005 to March 2006. MATERIALS： KA was provided by Sigma, USA. In situ hybridization detection kit of GBRla and GBR2 was provided by Wuhan Boster Biological Technology, China. GABABR agonist （baclofen） was provided by Sigma, USA. METHODS： Forty-four epileptic rats were randomly allocated to epileptic （n = 28） and drug intervention （n = 16） groups. The epileptic group was further divided into post-epileptic subgroups at different time points： 6, 12 hours, 1, 3, 7, 15, and 30 days （n = 4）. The drug intervention group was further divided into intervention controls subgroups at various time points： 6 hours, 1 day, and 3 days （n = 4）. Four additional rats were considered the normal control group and not modeled, but were injected with saline in the hippocampal CA3 region. MAIN OUTCOME MEASURES： GBRla and GBR mRNA expression was detected in the right hippocampal CA1, CA3, and dentate gyrus （DG） areas of the control, epileptic, and interference groups at various time intervals according to in situ hybridization results. RESULTS： （1） During the early stage of epilepsy （6 and 12 hours）, GBRla and GBR2 mRNA expression was decreased, and expression was less than the control group at one day after KA induction （P 〈 0.05）. mRNA expression was increased in the DG, but was greater than the control group at day 3 （P 〈 0.05）. Expression in the hippocampal CA1 and CA3 regions remained low （P 〈 0.05）, but gradually recovered to control levels. （2） The time points when subunit expression was decreased were prolonged following baclofen intervention, and expression was significantly greater than the epileptic group （P 〈 0.05）. CONCLUSION： Both mRNA expressions of GABABR subunits were up-regulated following decreased expression in the epileptic group, suggesting that the temporal lobe exhibited endogenous antiepileptic mechanisms during the early stages of epilepsy onset. Baclofen promoted mRNA expression of GBRla and GBR2.展开更多
Inhibitory neurotransmission ensures normal brain function by counteracting and integrating excitatory activity.-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the mammalian central nervous system...Inhibitory neurotransmission ensures normal brain function by counteracting and integrating excitatory activity.-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the mammalian central nervous system,and mediates its effects via two classes of receptors:the GABA A and GABA B receptors.GABA A receptors are heteropentameric GABA-gated chloride channels and responsible for fast inhibitory neurotransmission.GABA B receptors are heterodimeric G protein coupled receptors (GPCR) that mediate slow and prolonged inhibitory transmission.The extent of inhibitory neurotransmission is determined by a variety of factors,such as the degree of transmitter release and changes in receptor activity by posttranslational modifications (e.g.,phosphorylation),as well as by the number of receptors present in the plasma membrane available for signal transduction.The level of GABA B receptors at the cell surface critically depends on the residence time at the cell surface and finally the rates of endocytosis and degradation.In this review we focus primarily on recent advances in the understanding of trafficking mechanisms that determine the expression level of GABA B receptors in the plasma membrane,and thereby signaling strength.展开更多
This study investigated effects of post-training treatment with phaclofen, GABAB receptor antagonist, on the memory of food location and on the expression of Synapsin I in the hippocampus of pigeons. Pigeons were trai...This study investigated effects of post-training treatment with phaclofen, GABAB receptor antagonist, on the memory of food location and on the expression of Synapsin I in the hippocampus of pigeons. Pigeons were trained in food location (7 sessions) and underwent post-training treatment with phaclofen (0.3 mg/kg, i.p.;PHAC), saline (SAL) or non-treated (NTR). Testing for memory persistence occurred 7 days after the last training session (PHACR, SALR and NTRR Groups). Pigeons treated with phaclofen had lower latency and higher correct choice values than saline and non-treated controls (p < 0.05). Analysis of hippocampus tissue indicated that Synapsin I-positive cell counts were higher in pigeons treated with phaclofen than in saline and non-treated controls (p < 0.05). Data indicated enhancement of consolidation and persistence of food location memory, and up-regulation of Synapsin I expression in the hippocampus of pigeons, which were related with post-training blockade of GABAB receptors.展开更多
文摘Objectives: To investigate the potential role of GABAB Receptors (GABABRs) involved in the effect of Nourishing “Yin”-Removing “Fire” Chinese herb mixture (TCM) treatment on precocious puberty. Methods: Female Sprague-Dawley rats were randomly divided into four groups: normal (N), central precocious puberty (CPP) model (M), CPP fed with normal saline (S) and CPP fed with Nourishing “Yin”-Removing “Fire” Chinese herb mixture (TCM). Rats of postnatal day 5 were given a single subcutaneous injection of 240 μg danazol to establish CPP model rats. Rats of S and TCM groups were continuously administered with saline or nourishing “Yin”-removing “Fire” Chinese herb mixture since postnatal day 15. The expression of GABABRs was detected by means of real-time PCR and immunohistochemistry. Results: The expression of hypothalamic GnRH mRNA in M was significantly increased on the day of pre-puberty when compared with that of N (P < 0.01). On the day of onset-puberty, LH levels were higher in M than those in N (P < 0.01), while the serum E2 and LH levels of TCM decreased when compared with those of M (P <sub>B1</sub> receptor (GABABR1) immunoreactive cells in the arcuate nucleus (ARN) was decreased in M when compared with that of N (P < 0.05) and increased in TCM compared with that of M (P < 0.05);simultaneously, the expression of GABABR1 mRNA in hypothalamus was significantly decreased in M when compared with that of N (P < 0.01) and increased in TCM compared with that of M (P < 0.01). On the day of onset-puberty, the number of GABABR1 immunoreactive cells in medial septum (MS) was decreased in M compared with that in N (P < 0.05) and increased in TCM comparing with that of M (P < 0.05);meanwhile, the mRNA expression of GABABR1 in hypothalamus was decreased in M compared with that in N (P <sub>B2</sub> receptor (GABABR2) immunoreactive cells in the ARN, MS and diagnonal band of broca (DBB) were decreased in M when compared with those of N (P < 0.05) and increased in TCM compared with those of M (P < 0.05) on the day of onset-puberty. At the same time, the mRNA expression of GABABR2 was significantly decreased in M compared with that of N (P < 0.01). Conclusions: These results indicated that the GABABRs might involve in the curative effect of Nourishing “Yin”-Removing “Fire” Chinese herbal mixture on CPP rats.
文摘γ-amidobutyric acid (GABA) is a major inhibitory neurotransmitter in the central nervous system and mediates fast synaptic inhibition through GABAA and GABAC
文摘BACKGROUND： An amino acid imbalance has been considered to be responsible for epilepsy pathogenesis. Gamma-aminobutyric acid-B receptor （GABABR） inhibits voltage-sensitive calcium ion channels and GABA or glutamic acid （Glu） neurotransmitter release, which promotes or inhibits onset and development of epilepsy. OBJECTIVE： To explore the effect of baclofen on GBRla and GBR2 mRNA expression in the hippocampus of epileptic rats following kainic acid （KA） induction, and to study the adaptability of GABABR subunits. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment based on molecular biology was performed at the Laboratory Research Center of Second Hospital Affiliated to Soochow University from November 2005 to March 2006. MATERIALS： KA was provided by Sigma, USA. In situ hybridization detection kit of GBRla and GBR2 was provided by Wuhan Boster Biological Technology, China. GABABR agonist （baclofen） was provided by Sigma, USA. METHODS： Forty-four epileptic rats were randomly allocated to epileptic （n = 28） and drug intervention （n = 16） groups. The epileptic group was further divided into post-epileptic subgroups at different time points： 6, 12 hours, 1, 3, 7, 15, and 30 days （n = 4）. The drug intervention group was further divided into intervention controls subgroups at various time points： 6 hours, 1 day, and 3 days （n = 4）. Four additional rats were considered the normal control group and not modeled, but were injected with saline in the hippocampal CA3 region. MAIN OUTCOME MEASURES： GBRla and GBR mRNA expression was detected in the right hippocampal CA1, CA3, and dentate gyrus （DG） areas of the control, epileptic, and interference groups at various time intervals according to in situ hybridization results. RESULTS： （1） During the early stage of epilepsy （6 and 12 hours）, GBRla and GBR2 mRNA expression was decreased, and expression was less than the control group at one day after KA induction （P 〈 0.05）. mRNA expression was increased in the DG, but was greater than the control group at day 3 （P 〈 0.05）. Expression in the hippocampal CA1 and CA3 regions remained low （P 〈 0.05）, but gradually recovered to control levels. （2） The time points when subunit expression was decreased were prolonged following baclofen intervention, and expression was significantly greater than the epileptic group （P 〈 0.05）. CONCLUSION： Both mRNA expressions of GABABR subunits were up-regulated following decreased expression in the epileptic group, suggesting that the temporal lobe exhibited endogenous antiepileptic mechanisms during the early stages of epilepsy onset. Baclofen promoted mRNA expression of GBRla and GBR2.
基金Supported by The Swiss Science Foundation Grant,31003A_121963
文摘Inhibitory neurotransmission ensures normal brain function by counteracting and integrating excitatory activity.-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the mammalian central nervous system,and mediates its effects via two classes of receptors:the GABA A and GABA B receptors.GABA A receptors are heteropentameric GABA-gated chloride channels and responsible for fast inhibitory neurotransmission.GABA B receptors are heterodimeric G protein coupled receptors (GPCR) that mediate slow and prolonged inhibitory transmission.The extent of inhibitory neurotransmission is determined by a variety of factors,such as the degree of transmitter release and changes in receptor activity by posttranslational modifications (e.g.,phosphorylation),as well as by the number of receptors present in the plasma membrane available for signal transduction.The level of GABA B receptors at the cell surface critically depends on the residence time at the cell surface and finally the rates of endocytosis and degradation.In this review we focus primarily on recent advances in the understanding of trafficking mechanisms that determine the expression level of GABA B receptors in the plasma membrane,and thereby signaling strength.
文摘This study investigated effects of post-training treatment with phaclofen, GABAB receptor antagonist, on the memory of food location and on the expression of Synapsin I in the hippocampus of pigeons. Pigeons were trained in food location (7 sessions) and underwent post-training treatment with phaclofen (0.3 mg/kg, i.p.;PHAC), saline (SAL) or non-treated (NTR). Testing for memory persistence occurred 7 days after the last training session (PHACR, SALR and NTRR Groups). Pigeons treated with phaclofen had lower latency and higher correct choice values than saline and non-treated controls (p < 0.05). Analysis of hippocampus tissue indicated that Synapsin I-positive cell counts were higher in pigeons treated with phaclofen than in saline and non-treated controls (p < 0.05). Data indicated enhancement of consolidation and persistence of food location memory, and up-regulation of Synapsin I expression in the hippocampus of pigeons, which were related with post-training blockade of GABAB receptors.
