1. Septal GABAergic Neurons and Hippocampal Theta
Zsolt Borhegyi, Viktor Varga, Nora Szilagyi, Daniel Fabo, and Tamas F. Freund
Synchronous theta oscillations are one of the patterns of hippocampal activity thought to contribute to memory formation. The cholinergic and GABAergic neurons of the medial septum help drive these rhythms through reciprocal synaptic interactions with the hippocampus. The authors speculate that septal GABAergic neurons are wired to produce rhythmic hippocampal disinhibition in perisomatic and dendritic inhibitory interneurons at two phases of the theta rhythm.
2. A Shift in Tonic Inhibition with Chronic Seizures
Zechun Peng, Christine S. Huang, Brandon M. Stell, Istvan Mody, and Carolyn R. Houser
In this week's Journal, we are reminded that the often-neglected receptors in extrasynaptic locations can be important. The test case here is the au subunit of the GABAA receptor that is expressed in nonsynaptic sites. These subunits, with their high affinity for transmitter and slow desensitization, are poised to scavenge errant neurotransmitter molecules and thereby provide a tonic form of network inhibition. Peng et al. explore GABAA subunit expression in the dentate gyrus in an epilepsy model.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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Nothing in life is to be feared. It is only to be understood.
-- Marie Curie