scholarly journals GABA transporter 1 tunes GABAergic synaptic transmission at output neurons of the mouse neostriatum

2008 ◽  
Vol 586 (23) ◽  
pp. 5665-5678 ◽  
Author(s):  
Knut Kirmse ◽  
Anton Dvorzhak ◽  
Sergei Kirischuk ◽  
Rosemarie Grantyn
Synapse ◽  
2009 ◽  
Vol 63 (10) ◽  
pp. 921-929 ◽  
Author(s):  
Knut Kirmse ◽  
Sergei Kirischuk ◽  
Rosemarie Grantyn

Synapse ◽  
2005 ◽  
Vol 58 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Maksim V. Storozhuk ◽  
Svetlana Y. Ivanova ◽  
Pavel M. Balaban ◽  
Platon G. Kostyuk

2020 ◽  
pp. 7-12
Author(s):  
Л. И. Хожай

Цель работы - исследование распределения уровня GAT-транспортера ГАМК в комплексе Бетцингера на разных сроках раннего постнатального развития крыс в норме и при пренатальном дефиците серотонина. Материал и методы. Работа проведена на лабораторных крысах линии Wistar. Снижение уровня эндогенного серотонина в эмбриональный период осуществляли методом ингибирования триптофан-гидроксилазы пара-хлорфенилаланином (пХФА). Выявление транспортного белка GAТпроводили посредством иммуногистохимической реакции с использованием первичных кроличьих поликлональных антител anti-GABA transporter1 (AbCam, Великобритания). Мозг исследовали на 5-, 10-е и 20-е сутки постнатального развития. Результаты. В комплексе Бетцингера на ранних сроках постнатального развития у контрольных животных отмечено колебание уровня GAT-транспортера ГАМК. На 1-й неделе жизни уровень GATбыл высоким как в сети отростков и терминалей, так и в синапсах. В течение 2-й недели жизни уровень GATснижался, а к концу 3-й недели - повышался вновь, достигая исходного уровня. Дефицит серотонина в пренатальный период вызывал у подопытных животных существенное увеличение уровня GATв нейропиле комплекса Бетцингера на всех изученных сроках постнатального развития. Выводы. Пренатальный дефицит серотонина приводит к существенному повышению уровня GAT-транспортера ГАМК в ранние сроки постнатального развития, что может приводить к изменению трансмиссии ГАМК и, как следствие, к нарушению баланса тормозных и возбуждающих эффектов в дыхательном ядре. Objective - to study the distribution of GABA transporter 1 (GAT) levels in the Bötzinger complex at the early stages of postnatal development in rats with prenatal serotonin deficiency. Materials and methods. The work was carried out on Wistar line laboratory rats. To reduce the level of endogenous serotonin in the embryonic period, the method of tryptophan hydroxylase inhibition by para-chlorophenylalanine (PCPA) (Sigma, USA) was used. The GAT1 transport protein was detected by immunohistochemical reaction with anti-GABA transporter1 primary rabbit polyclonal antibodies (AbCam, UK). The brain was examined on the 5, 10 and 20 day of postnatal development. Results. At the early stages of postnatal development, a fluctuation in the GAT1 level of the GABA transporter was noted in the Bötzinger complex of control animals. In the first postnatal week, the GAT level was high both in the network of neuronal processes and terminals, and in synapses. During the 2 week of life, the GAT1 level decreased, and by the end of the 3 week it increased again, reaching the initial level. Deficiency of serotonin in the prenatal period caused a significant increase in the level of GAT in the neuropil of the Bötzinger complex in experimental animals at all studied stages of postnatal development. Conclusions. Prenatal deficiency of serotonin leads to a significant increase in the GAT1 level at the early stages of postnatal development, which can lead to a change in the GABA transmission, and, as a result, to a disturbance in the balance of inhibitory and stimulatory effects in the respiratory nuclei.


2003 ◽  
Vol 90 (4) ◽  
pp. 2690-2701 ◽  
Author(s):  
Kimmo Jensen ◽  
Chi-Sung Chiu ◽  
Irina Sokolova ◽  
Henry A. Lester ◽  
Istvan Mody

After its release from interneurons in the CNS, the major inhibitory neurotransmitter GABA is taken up by GABA transporters (GATs). The predominant neuronal GABA transporter GAT1 is localized in GABAergic axons and nerve terminals, where it is thought to influence GABAergic synaptic transmission, but the details of this regulation are unclear. To address this issue, we have generated a strain of GAT1-deficient mice. We observed a large increase in a tonic postsynaptic hippocampal GABAA receptor-mediated conductance. There was little or no change in the waveform or amplitude of spontaneous inhibitory postsynaptic currents (IPSCs) or miniature IPSCs. In contrast, the frequency of quantal GABA release was one-third of wild type (WT), although the densities of GABAA receptors, GABAB receptors, glutamic acid decarboxylase 65 kDa, and vesicular GAT were unaltered. The GAT1-deficient mice lacked a presynaptic GABAB receptor tone, present in WT mice, which reduces the frequency of spontaneous IPSCs. We conclude that GAT1 deficiency leads to enhanced extracellular GABA levels resulting in an overactivation of GABAA receptors responsible for a postsynaptic tonic conductance. Chronically elevated GABA levels also downregulate phasic GABA release and reduce presynaptic signaling via GABAB receptors thus causing an enhanced tonic and a diminished phasic inhibition.


Author(s):  
Benjamin K. Lau ◽  
Brittany P. Ambrose ◽  
Catherine S. Thomas ◽  
Min Qiao ◽  
Stephanie L. Borgland

AbstractThe orbitofrontal cortex (OFC) plays a critical role in evaluating outcomes in a changing environment. Administering opioids to the OFC can alter the hedonic reaction to food rewards and increase their consumption in a subregion specific manner. However, it is unknown how mu-opioid signalling influences synaptic transmission in the OFC. Thus, we investigated the cellular actions of mu-opioids within distinct subregions of the OFC. Using in-vitro patch clamp electrophysiology in brain slices containing the OFC, we found that the mu-opioid agonist, DAMGO produced a concentration-dependant inhibition of GABAergic synaptic transmission onto medial OFC (mOFC), but not lateral OFC (lOFC) neurons. This effect was mediated by presynaptic mu-opioid receptor activation of local parvalbumin (PV+)-expressing interneurons. The DAMGO-induced suppression of inhibition was long-lasting and not reversed upon washout of DAMGO, or by application of the mu-opioid receptor antagonist, CTAP, suggesting an inhibitory long-term depression (iLTD) induced by an exogenous mu-opioid. We show that LTD at inhibitory synapses is dependent on downstream cAMP/PKA signaling, which differs between the mOFC and lOFC. Finally, we demonstrate that endogenous opioid release triggered via moderate physiological stimulation can induce LTD. Taken together, these results suggest that presynaptic mu-opioid stimulation of local PV+ interneurons induces a long-lasting suppression of GABAergic synaptic transmission, which depends on subregional differences in mu-opioid receptor coupling to the downstream cAMP/PKA intracellular cascade. These findings provide mechanistic insight into the opposing functional effects produced by mu-opioids within the OFC.Significance StatementConsidering that both the OFC and the opioid system regulate reward, motivation, and food intake; understanding the role of opioid signaling within the OFC is fundamental for a mechanistic understanding of the sequelae for several psychiatric disorders. This study makes several novel observations. First, mu-opioids induce a long-lasting suppression of inhibitory synaptic transmission onto OFC pyramidal neurons in a regionally selective manner. Secondly, mu-opioids recruit PV+ inputs to suppress inhibitory synaptic transmission in the mOFC. Thirdly, the regional selectivity of mu-opioid action of endogenous opioids is due to the efficacy of mu-opioid receptor coupling to the downstream cAMP/PKA intracellular cascades. These experiments are the first to reveal a cellular mechanism of opioid action within the OFC.


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