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GABAergic

About: GABAergic is a research topic. Over the lifetime, 9595 publications have been published within this topic receiving 473568 citations.


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Book ChapterDOI
TL;DR: The paraventricular nucleus of the hypothalamus is uniquely situated to coordinate responses of multiple stress effector systems in the face of prolonged stimulation, and likely plays a role in both adaptation and pathology associated with chronic stress.
Abstract: Proper integration and execution of the physiological stress response is essential for maintaining homoeostasis. Stress responses are controlled in large part by the paraventricular nucleus (PVN) of the hypothalamus, which contains three functionally distinct neural populations that modulate multiple stress effectors: (1) hypophysiotrophic PVN neurons that directly control the activity of the hypothalamic-pituitary-adrenocortical (HPA) axis; (2) magnocellular neurons and their secreted neurohypophysial peptides; and (3) brainstem and spinal cord projecting neurons that regulate autonomic function. Evidence for activation of PVN neurons during acute stress exposure demonstrates extensive involvement of all three effector systems. In addition, all PVN regions appear to participate in chronic stress responses. Within the hypophysiotrophic neurons, chronic stress leads to enhanced expression of secreted products, reduced expression of glucocorticoid receptor and GABA receptor subunits and enhanced glutamate receptor expression. In addition, there is evidence for chronic stress-induced morphological plasticity in these neurons, with chronic drive causing changes in cell size and altered GABAergic and glutamatergic innervation. The response of the magnocellular system varies with different chronic exposure paradigms, with changes in neurohypophysial peptide gene expression, peptide secretion and morphology seen primarily after intense stress exposure. The preautonomic cell groups are less well studied, but are likely to be associated with chronic stress-induced changes in cardiovascular function. Overall, the PVN is uniquely situated to coordinate responses of multiple stress effector systems in the face of prolonged stimulation, and likely plays a role in both adaptation and pathology associated with chronic stress.

130 citations

Journal ArticleDOI
TL;DR: The behaviour-contingent rhythmic synchronization of neuronal activity is reported by local field potential oscillations in the theta, gamma and sharp wave-related ripple (SWR) frequency ranges and the key inhibitory role of axo-axonic cells is demonstrated.
Abstract: The behaviour-contingent rhythmic synchronization of neuronal activity is reported by local field potential oscillations in the theta, gamma and sharp wave-related ripple (SWR) frequency ranges. In the hippocampus, pyramidal cell assemblies representing temporal sequences are coordinated by GABAergic interneurons selectively innervating specific postsynaptic domains, and discharging phase locked to network oscillations. We compare the cellular network dynamics in the CA1 and CA3 areas recorded with or without anaesthesia. All parts of pyramidal cells, except the axon initial segment, receive GABA from multiple interneuron types, each with distinct firing dynamics. The axon initial segment is exclusively innervated by axo-axonic cells, preferentially firing after the peak of the pyramidal layer theta cycle, when pyramidal cells are least active. Axo-axonic cells are inhibited during SWRs, when many pyramidal cells fire synchronously. This dual inverse correlation demonstrates the key inhibitory role of axo-axonic cells. Parvalbumin-expressing basket cells fire phase locked to field gamma activity in both CA1 and CA3, and also strongly increase firing during SWRs, together with dendrite-innervating bistratified cells, phasing pyramidal cell discharge. Subcellular domain-specific GABAergic innervation probably developed for the coordination of multiple glutamatergic inputs on different parts of pyramidal cells through the temporally distinct activity of GABAergic interneurons, which differentially change their firing during different network states.

130 citations

Journal ArticleDOI
TL;DR: Combining calcium transients associated with network-driven giant depolarizing potentials or GDPs generated by the synergistic action of glutamate and GABA with MF activation increased the probability of GABA release and caused the conversion of silent synapses into conductive ones suggesting that GDPs act as coincident detector signals for enhancing synaptic efficacy.
Abstract: In this review some of the recent work carried out in our laboratory concerning the functional role of GABAergic signalling at immature mossy fibres (MF)-CA3 principal cell synapses has been highlighted. While in adulthood MF, the axons of dentate gyrus granule cells release onto CA3 principal cells and interneurons glutamate, early in postnatal life they release GABA, which exerts into targeted cells a depolarizing and excitatory action. We found that GABAA-mediated postsynaptic currents (MF-GPSCs) exhibited a very low probability of release, were sensitive to L-AP4, a group III metabotropic glutamate receptor agonist, and revealed short-term frequency-dependent facilitation. Moreover, MF-GPSCs were down regulated by presynaptic GABAB and kainate receptors, activated by spillover of GABA from MF terminals and by glutamate present in the extracellular medium, respectively. Activation of these receptors contributed to the low release probability and in some cases to synapses silencing. By pairing calcium transients, associated with network-driven giant depolarizing potentials or GDPs (a hallmark of developmental networks thought to represent a primordial form of synchrony between neurons), generated by the synergistic action of glutamate and GABA with MF activation increased the probability of GABA release and caused the conversion of silent synapses into conductive ones suggesting that GDPs act as coincident detector signals for enhancing synaptic efficacy. Finally, to compare the relative strength of CA3 pyramidal cell output in relation to their MF glutamatergic or GABAergic inputs in adulthood or in postnatal development, respectively, a realistic model was constructed taking into account different biophysical properties of these synapses.

130 citations

Journal ArticleDOI
TL;DR: In stressed rats, the 5-HT2A receptor-mediated facilitative actions were severely impaired, which might result in an amygdala circuitry with hyperexcitability, and a lower threshold of activation, and thus be an important mechanism underlying the emergence of stress-associated psychiatric symptoms.

130 citations

Journal ArticleDOI
TL;DR: Sandor L. Erdo summarizes the current knowledge of GABAergic systems in peripheral tissues and emphasizes the functional relevance of GABA in a series of peripheral organs.

130 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023371
2022749
2021341
2020320
2019301
2018297