- Structural: They are involved in the physical structuring of the brain. Astrocytes get their name because they are “star-shaped”. They are the most abundant glial cells in the brain that are closely associated with neuronal synapses. They regulate the transmission of electrical impulses within the brain.
- Glycogen fuel reserve buffer: Astrocytes contain glycogen and are capable of glycogenesis. Thus, astrocytes can fuel neurons with glucose during periods of high rate of glucose consumption and glucose shortage.
- Metabolic support: They provide neurons with nutrients such as lactate.
- Blood–brain barrier: The astrocyte end-feet encircling endothelial cells were thought to aid in the maintenance of the blood–brain barrier.
- Transmitter uptake and release: Astrocytes express plasma membrane transporters such as glutamate transporters for several neurotransmitters, including glutamate, ATP, and GABA.
- Regulation of ion concentration in the extracellular space: Astrocytes express potassium channels at a high density. When neurons are active, they release potassium, increasing the local extracellular concentration. Because astrocytes are highly permeable to potassium, they rapidly clear the excess accumulation in the extracellular space.[
- Modulation of synaptic transmission and memory formation:
- Vasomodulation: Astrocytes may serve as intermediaries in neuronal regulation of blood flow.
- Promotion of the myelinating activity of oligodendrocytes: Electrical activity in neurons causes them to release ATP, which serves as an important stimulus for myelin to form. However, the ATP does not act directly on oligodendrocytes. Instead, it causes astrocytes to secrete cytokine leukemia inhibitory factor (LIF), a regulatory protein that promotes the myelinating activity of oligodendrocytes.
- Nervous system repair: Upon injury to nerve cells within the central nervous system, astrocytes fill up the space to form a glial scar, and may contribute to neural repair. Although, the glial scar has traditionally been described as an impermeable barrier to regeneration.
A1 (Toxic) astrocytes, which are induced by injury, neuroinflammation, and neurodegenerative disease, produce proinflammatory molecules.
These molecules all come from hot microglia, which in this study was mimicked by an infection
Well a recent paper suggests something
Li S, Uno Y, Rudolph U, Cobb J, Liu J, Anderson T, Levy D, Balu DT, Coyle JT. Astrocytes in primary cultures express serine racemase, synthesize d-serine and acquire A1reactive astrocyte features. Biochem Pharmacol. 2018. pii: S0006-2952(17)30735-9.
d-Serine is a co-agonist at forebrain N-methyl-d-aspartate receptors (NMDAR) and is synthesized by serine racemase (SR). A1 reactive astrocytes express SR and release d-serine under pathologic conditions, which may contribute to their neurotoxic effects by activating extra-synaptic NMDA receptors.
So the axis of evil could be
B cells——Hot Microglial——-Astrocytes—–Nerve damage
Plus abit more
B cells——Nerve damage
B cells——Hot Micrroglia——-Nerve damage
T cells——Hot Microglia——–Nerve damage
Infection—Hot Microglia——–Nerve damage
There are many targets in these pathways the central issue is to find those that do not cause too many side-effect