User:Neuronchik

From NeuronBank
Jump to: navigation, search

Chandelier Cell

Chandelier cell is unusual Y--aminobutityric acidergic interneurons located in the cerebral cortex.(2)

NS neuron

Basic Information The Chandelier cell is an GABA interneuron.(1) This cell is believed to be responsible for epilepsy as well as higher logic in humans compared to any other mammal.(3) Chandelier cell has direct links to be causing tempotal lobe epilepsy. The location of epileptic foci shows decreased amount of cells in researched humans and animals which leads to epilepsy. The main factors for epilepsy is loss of neurons, which might be thru lesions. Chandelier cells are found in all mammals. The diferences of how human chandelier cells interactcompared to any other mammalian chandelier cell might be the answer to human inteligence and other advantages human has over other mammals, such as speech, etc.(4)

Neuronal Type: local interneuron.

Anatomy

The Chandelier cell has smooth non spiny dendrites with vertical projections at the ends of short axons called, Ch terminals, which look like candlesticks. The overall appearance of a cell bears resemblence of a chandelier and thats were the name comes from. The main location for chandelier cells is cerebral cortex. They also can be found in parts of these cortexes: paleocortex, archicortex and mesocortex, which include the piriform cortex, entorhinal cortex, subiculum, hippocampus, fascia dentata and cingulate cortex.(2) The number of Chandelier cells is in a very small percentage compared to all GABA interneurons. Initially chandelier cell was missed by Cajal and Lorente. The identification came from Szentagothai and Arbib on 1974.(4)

Molecular profile

  • Neurotransmitter: _Chandalier cells use γ-amino butyric acid as inhibitory transmitter which relates them to GABA . It helps chandelier cells to depolarize pyramidal cells because cell soma is less depolarized than the axon due to chloride reversal potential.(1)


Physiology

Synaptic Connections

Synaptic Inputs/Synaptic Outputs

It takes only one action potential from Chandelier cell to send multiple spikes to pyramidal cells, thus enabling cortical microcircuit. Spikes in the pyramidal neurons exhibit excitatory feedback towards chandelier cells. The feedback occurance was noted in the amygdala making it possible for chandelier cell role to be beyond its initial thought premises. Chandelier cells use pyramidal neurons to send many synapses to the initial axon segment, the place of action potential. The depolarizing shift in EGABA was reported to come from dendride to soma to axon. In addition axon favor of NKCCl,chloride importer, might be a way of keeping EGABA depolirized.(4)

Spiking properties

The spikes have shown to be temporal and precise with low jigger, when studies were done in vivo and in vitro.(5) Studies in mice cerebral cortex testing for spike quickness by the means of brief pulse injections of depolarizing current with a train of narrow action potentials have shown chandelier cell to respond very quickly.(1) The pyramidal cell because of action potential, spikes chandelier cell. Cahndelier strikes second pyramidal cell, which goes into postsynaptic strike for another chandelier cell.While this takes place second pyramidal cell stimulate chandalier and basket cell to a treshhold. Basket cell creates ISPS on the third pyramidal cell. The chandelier cell that spikes activates another neuron to fire. The whole sequence of events results in ESPS-ISPS-ESPS.(4)

References

1 DeFelipe J. (1999) Chandelier cells and epilepsy, Brain, 122: 1807-1822. http://brain.oxfordjournals.org/cgi/content/full/122/10/1807?ijkey=f2112721a9a060390c8a5845d44e70975a7a1a63

2 DeFelipe J.,Inda MC, Muñoz (2009) A Morphology and Distribution of Chandelier Cell Axon Terminals in the Mouse Cerebral Cortex and Claustroamygdaloid Complex, Cerebral Cortex, 19(1):41-54.http://cercor.oxfordjournals.org/misc/terms.shtml

3 Randhawa G. (2008) How chandelier cells light up human thought , New Schientist. http://www.newscientist.com/article/dn14655-how-chandelier-cells-light-up-human-thought.html?feedId=online-news_rss20

4 Woodruff A.,Yuste R. (2008) Of Mice and Men, and Chandeliers, PLoS, 6(9):1833-1836. http://ezproxy.gsu.edu:2048/login?url=http://search.ebscohost.com/login.aspx?direct=true&db=a9h&AN=34582505&site=ehost-live

Additional information

Pictures [brain.oxfordjournals.org/.../issue10/cover.dtl ]