คาสิโนไทย Local Synchronization via Interneurons MT

 

All forms of physiological gamma rhythm (30-80 Hz) are inhibition based (Whittington et al., 2011; Sohal et al., 2009). That is, the neurons (e.g., pyramidal cells) without electrical coupling can be synchronized by forming chemical synapses with an inhibitory GABAergic neuron such as the parvalbumin (PV)-positive fast spiking (FS) cell which oscillates at the gamma band. Its mechanism is illustrated in Figure 1. Without inhibition, a group of pyramidal cells may oscillate at certain frequency with random phases. When the inhibitory neuron fires, it can inhibit all connected pyramidal cells simultaneously. As the inhibition decays, the pyramidal cells will resume their oscillations. Consequently, the aggregated activity of connected pyramidal cells will be paced by the inhibitory neuron (คาสิโนไทยGonzalez-Burgos et al., 2011).

There are two types of PV neurons: basket cells that make synapses at the soma and proximal dendrite of target neurons and chandelier cells which target the axon initial segment (AIS) of pyramidal cells (คาสิโนไทยRudy et al., 2011). A basket cell may connect up to 1,000 pyramidal cells (Halasy et al., 1996). When a group of basket cells are synchronized by gap junctions (คาสิโนไทย), they will be able to recruit a large population of neurons into synchronization.

Image

Figure 1. A model for the mechanism of synchronization mediated by interneurons.
Left panel: An inhibitory GABAergic interneuron targets a group of pyramidal cells.
Right panel: Black traces represent the membrane potential of the GABA neuron which remains at rest before and after firing a sequence of four action potentials.
Red traces show the membrane potential simultaneously recorded from the postsynaptic pyramidal neurons, which are firing in response to a continuous excitatory input.
Note that, before the GABA neuron starts firing, the pyramidal cells fire in an asynchronous manner. Shortly after GABA neuron spikes (indicated by black arrows), all pyramidal neurons are inhibited simultaneously. After the inhibition decays, the pyramidal neurons fire in nearly synchrony.
[Source: Gonzalez-Burgos et al., 2011]

 

Author: Frank Lee
First published: February 13, 2013
Last updated: August, 2018