Astrocytes

Also known as:  Astroglial Cells

Astrocytes are a type of Macroglia Glial Cell that is capable of dividing (i.e. of reproducing).  They are one of several types of Glial Cells that collectively form the Glia.

Nervous System

 Astrocytes use their "feet" to attach themselves to the outer surface of neighboring Capillaries that form the Blood-Brain Barrier.  They contribute to the Blood-Brain Barrier by further blocking chemicals that manage to pass through the Endothelial Cells of the Blood-Brain Barrier.

 Astrocytes are believed to be responsible for the delivery of nutrients to Neurons.

 Astrocytes "mop up" excessive Neurotransmitters around Neurons, thereby preventing Neurons from becoming over-stimulated.

 Astrocytes are one of the types of Cells that produce Nerve Growth Factor (NGF).

 Astrocytes produce the Estradiol 17-Beta form of Estradiol (an Estrogen) within the Brain:  ^[1]

 The production of this Astrocyte-derived Estradiol 17-Beta is catalyzed by Aromatase enzymes that reside in the Cytoplasm of Astrocytes.