Synapse GABAergic

Altered synaptic properties Numerous changes in the properties of inhibitory (GABAergic) and excitatory (glutamatergic) synapses have been reported. While the simple adage of an imbalance between inhibitory and excitatory neurotransmission in epilepsy is not generally applicable, some forms of inhibition are lost or impaired in epilepsy. Likewise, an increased function of glutamate receptors has been demonstrated in some brain areas. 

Gupta, A, Wang, Y and Markram, H (2000) Organizing principles for a diversity of GABAergic interneurons and synapses in the neocortex. Science 287 213-218. 

Fig. 45. GABAergic neurone synapse. GAD, glutamic acid decarboxylase M, mito-chodria G, GABA. 

Woodin, M. A., Ganguly, K. and Poo, M.-M. Coincident pre- and postsynaptic activity modifies GABAergic synapses by postsynaptic changes in CT transporter activity. Neuron 39 807-820, 2003. 

Fritschy, J.-M. and Brunig, I. Formation and plasticity of GABAergic synapses physiological mechanisms and pathophysiological implications. Pharmacol. Ther. 98 299-323, 2003. 

Facilitatory actions of presynaptic kainate receptors (82,88) were long overshadowed by the pronounced inhibitory effects of kainate receptor agonists on both gluta-matergic and GABAergic transmission. Recently, facilitation of synaptic transmission via activation of a presynaptic kainate receptors has been described in the GABAergic synapses in area CA1 (86), in the spinal cord (99), and probably most thoroughly, in the mossy-hber synapse in area CA3 (39,77,100). 

GABAergic inhibition between interneurones can also be enhanced by glutamate spillover from neighboring excitatory synapses acting on kainate receptors (38). In CA1 interneurones, an increase in spontaneous action potential discharge and consequent increase in spontaneous IPSC frequency is observed to kainate and ATPA application (34,36,46,63,83,96,98,103). These effects are in part owing to direct depolarization of... 

Meister, B. and Hokfelt, T. (1988) Peptide- and transmitter-containing neurons in the mediobasal hypothalamus and their relation to GABAergic systems possible roles in control of prolactin and growth hormone secretion. Synapse 2, 585-605. 

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