Neurons, like all other cells, require energy to function. This energy is supplied in the form of glucose and oxygen (the oxygen being carried in haemoglobin). The blood supply of the brain is dynamically regulated to give active neural assemblies more energy whilst inactive assemblies receive less energy. This dynamic regulation of the blood flow (haemodynamic) is the principal on which functional magnetic resonance imaging is based. Neurons (also spelled neurones or called nerve cells) are the primary cells of the nervous system. ... A space-filling model of glucose Glucose, a simple monosaccharide sugar, is one of the most important carbohydrates and is used as a source of energy in animals and plants. ... General Name, Symbol, Number Oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16 (VIA), 2, p Density, Hardness 1. ... General Name, Symbol, Number Oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16 (VIA), 2, p Density, Hardness 1. ... 3-dimensional structure of hemoglobin Hemoglobin or haemoglobin is the iron-containing oxygen-transport metalloprotein in the red cells of the blood in mammals and other animals. ... Functional Magnetic Resonance Imaging (or fMRI) describes the use of MRI to measure hemodynamic signals related to neural activity in the brain or spinal cord of humans or other animals. ...

The molecular biology of haemodynamic regulation

1. Active excitatory neurons release the neurotransmitter glutamate
2. Glutamate opens NMDA receptors on other neurons which allows calcium ions into the neuron
   1. Calcium activates nitric oxide sythase which produces nitric oxide
   2. Nitric oxide diffuses out and dilates smooth muscle surrounding local arterioles
   3. This dilation allows more blood into the local capillaries
   4. hence more oxygen and glocose reaches the neurons
3. Glutamate also opens mGluR receptors on astrocytes
   1. this allow calcium into the astrocyte
   2. which activates phospholipase A2 (PLA2)
   3. which produces arachidonic acic (AA)
   4. which is converted by cyclo-oxygenase
   5. into PGE2
   6. which dilates local smooth muscle and allows greater blood flow

Neurons (also spelled neurones or called nerve cells) are the primary cells of the nervous system. ... Glutamic acid or glutamate is one of the 20 most common natural amino acids. ... Glutamic acid or glutamate is one of the 20 most common natural amino acids. ... NMDA (N-methyl-D-aspartic acid) is an amino acid derivative acting as specific agonist at the NMDA receptor, and therefore mimics the action of the neurotransmitter glutamate on that receptor. ... General Name, Symbol, Number calcium, Ca, 20 Series alkaline earth metal Group, Period, Block 2 (IIA), 4, s Density, Hardness 1550 kg/m3, 1. ... The chemical compound nitric oxide is a gas with chemical formula NO. It is an important signaling molecule in the body of mammals including humans, one of the few gaseous signaling molecules known. ... Smooth muscle is a type of non-striated muscle, found within the walls of hollow organs; such as blood vessels, bladders, uteri. ... An arteriole is a blood vessel that extends and branches out from an artery and leads to capillaries. ... Glutamic acid or glutamate is one of the 20 most common natural amino acids. ... Astrocytes, also known as astroglia, are characteristic star-shaped cells in the brain. ... A phospholipase is an enzyme that converts phospholipids into fatty acids and other lipophilic substances. ... Cyclooxygenase (COX) is an enzyme that is responsible for formation of important biological mediators called prostanoids (including prostaglandins, prostacyclin and thromboxane). ... Smooth muscle is a type of non-striated muscle, found within the walls of hollow organs; such as blood vessels, bladders, uteri. ...

References