Astrocyte: Structure, Function and Disease

Astrocytes are star shaped glial cells which are found associated with the neurons of the CNS and spinal cord.  They modulate the aspects related to neural network functions. Express the same sets of ion channels as neurons, but in varying proportion. Maintenance of K+ and water homeostasis in the CNS via coordinated action of Kirl.4 and aquaporin 4 channels. Gap junctions form intercellular networks and help in sequestering K+ and glutamate. Modulation of synaptic transmission.  1. Lamellar fibrous astrocytes Found in white matter Oriented parallel to the neuronal axons Higher levels of GFAP End feet envelops the...

Read More

Role of Fibroblast growth factor (FGF) in neural stem cell growth

Fibroblast growth factor (FGF) constitutes a large family of polypeptide growth factors found in a variety of multicellular organisms, including invertebrates. The function of FGFs is not restricted to cell growth. Instead, FGFs are involved in diverse cellular processes including chemotaxis, cell migration, differentiation, cell survival, and apoptosis. The common feature of FGFs is that they are structurally related and generally signal through receptor tyrosine kinases. FGFs play an important role in embryonic development in invertebrates and vertebrates. The human FGF protein family consists of 22 members that share a high affinity...

Read More

Hedgehog protein – signaling pathway in vertebrate neural development

Hedgehog family of proteins is signaling proteins which control the cell growth, survival, fate and pattern (almost every aspect) of the vertebrate body plan.  The name was derived from the short and spiked phenotype of the cuticle of the Hh mutant Drosophila larvae. Except in C.elegans, It is found in both vertebrates and invertebrates. In C.elegans, it has several proteins homologous to the Hh receptor Ptc.   There are three subgroups in hedgehog protein family:                     A.  Desert hedgehog (Dhh)                  ...

Read More

Microtubules: Role in axon and dendrites formation

Polarized cells such as neurons have two distinct domains i.e. molecular and functional domains which have been emerged from the cell body. In neurons, axon and dendrites are two distinct functional units emerged from the cell body by the process called neuronal polarity. Axons are thin, single and long structure which will transmit the signals to the target or synaptic partner. Whereas dendrites are shorter, multiple structures which has the ability to receive signals from different regions of cells or axons. Before getting with role of microtubules in axon and dendrite formation, we need to look into the neuronal polarity part which...

Read More

Growth cone and its role in axonal guidance

Growth cone are specialized and highly motile cellular compartment at the tips of the growing axon which supports the growth of the axon by sensing the extracellular cues and transducing it to the cytoskeletons. The structure consists of a central region filled with organelles and microtubules; whereas at the peripheral region, it has highly dynamic, actin rich region such as Lamellipodia and Filopodia. Lamellipodia are the broad veil like cellular protrusions that contain branched actin filaments. Filopodia are thin protrusions made out of unbranched and parallel F actin bundles.  ...

Read More