The article covers various aspects of astrocyte functioning in association with experimental basis on hippocampus cultures, cell cultures and imaging techniques. Interesting observations have been elaborated with regard to the calcium waves phenomenon and consequences of release of glutamate. Back in 1894, Rudolf Virchow referred to astrocytes as "glia", meaning "glue", as they were believed to be holding the neuronal elements together. Astrocytes: neuron ratio is approximately 10:1 and despite the larger number of astrocytes, it was neurons that were considered to perform the primary function of the nervous system. The increase in intracellular Ca[2+] level led to release of glutamate which in turn helped in modulating synapses to allow the conduction of the nerve impulse.
The article, which spans over 14 pages, indeed provides a thorough, detailed insight in the working of astrocytes. It commences with a short description of the previously built information regarding astrocytes, and gradually gravitates towards
the new findings regarding the functioning of astrocytes ...
rding the functioning of astrocytes due to elevated intracellular calcium level as a result of various neurotransmitters like GABA, ATP, and glutamate. It has been brought forward that a calcium elevation in astrocytes is both necessary and sufficient to modulate synaptic transmission and to activate ionotropic glutamate receptors on hippocampal neurons.
It is also supplemented by pictures, which are extremely useful for the comprehension of this thesis. The authors have no doubt done a good job in writing up this article. Not only has the information been provided with a systematic and methodical approach, it has been made sure that each conclusion that has been concurred has a factual experimental basis, which is mandatory and extremely impressive, especially as figurative data has been imparted. Though the material has been extrapolated and unnecessarily lengthened a few times due to repetition of certain clauses that could have been avoided, overall it provides all the essential information that a student would require.
What has been most intriguing is the function of astrocytes as vasomodulators, ie, as intermediary regulators of blood flow and experimental basis showing that application of neurotransmitters like norepinephrine, acetylecholine can mobilize astrocytic calcium, suggesting extrinsic axon pathways can also act on astrocytes to regulate the calcium.
The basis for bi-directional glutamate-mediated signalling between astrocytes and neurons is unclear and the concept of neuroligands is enlightening. The various experiments employed to support the notion that glutamate is the neurotransmitter mediating astrocyte-neuron signaling are satisfactory, however the fact that the researchers have gone one step further to explore the action of other