Overdose in the hippocampus; when everything means something.  High levels of dopamine are associated with psychotic episodes and schizophrenia.  However, if this is so, it is rarely noted the damage that low levels of somatostatin can create.  High dopamine/low somatostatin.  Firstly, dopamine levels have an important role in memory as discussed in the Alzheimer’s papers.  Dopamine is crucial in playing a part in developing the ensembles/memories. Every memory begins with a stimulus and also needs inhibition, which is what somatostatin provides.  If somatostatin levels are too low the memory cannot be formed or is lost.  This is why people who have a psychotic episode usually fail to remember what transpires in that time.  Those who suffer from schizophrenia or a schizo-affective disorder and not experiencing psychosis have more acceptable levels of dopamine and somatostatin.  However the ratio of dopamine to somatostatin is still flawed.  High-ish dopamine levels and low-ish somatostatin can still deliver a functioning mind.  An individual can experience a psychotic episode and never experience another one. 

The problem with memories built on high dopamine is that there is high reward to remember them.  The want of replaying memories between the neo cortex and the hippocampus becomes relentless.  In saying this thoughts then can present as being intrusive.   In psychosis the higher the dopamine associated memories, the more likely they will be recalled.  This means that these vivid memories may well be distorted. The mind will keep targeting high dopamine memories and somatostatin will continue to get lower.  This eventually results in hippocampus dysfunction.  The hippocampus cannot work with any competency under these circumstances.  The hippocampus signals through the entorhinal cortex to the rest of the brain; obviously are not healthy regions.  Therefore any feedback or signals received by the entorhinal cortex is not helpful to the mayhem that is occurring in the hippocampus.  Of course the neocortex also is directly influenced by this activity.  Eventually the whole brain is consumed with over-connectivity and has little ability to process day to day proceedings.  This also may be the birth of paranoia as perception of stimulus is altered.  In a healthy brain cortisol levels would rise dramatically and burn out receptors that dopamine and serotonin attach to.  A low reading of cortisol in the morning can indicate a higher chance of a psychotic episode occurring. 

Somatostatin regulates dopamine but is insignificant quantities to be able to make any sort of helpful adjustment.  The schizophrenic brain then chases psychotic episodes as it pursues the high dopamine that is associated with it.  Further damage is done when modulation of glial cells falls on dopamine levels.  Also somatostatin being severely low (especially around psychotic episodes and paranoia) the results are damning to say the least.

Somatostatin acts as a buffer when synaptic pruning takes place.  Its close association with microglia makes this process a finely measured event.  Synaptic pruning is a constant event in the adult schizophrenic brain which may stress an individual and cause confusion.  Consequently in this illness the brain shrinks by 5-7% over a life time.  Somatostatin promotes REM sleep.  It plays an important role with learning and memory.  A lag in this area can only be detrimental to retaining strong consistent platforms of information.   

The astrocytes play a major role in the etiology and pathogenesis of schizophrenia.  By providing an unstable neuronal working environment it loses control of levels of neurotransmitters around synapses and is less efficient at modifying them.  Oligodendrocytes are abnormal and myelin dysfunction is common.  Also early testing of cerebrospinal fluid may be an indicator of the risk of the development of schizophrenia. 

Radial cells, Schwann cells, Satellite cells all work with functions that assist in the smooth running of the central nervous system.  With schizophrenia they are all compromised.  Psychosis where everything means something has to find a way to proceed.

Functions of Glia Cells

Microglia – brains immune cells, protects against in jury and disease.  Removes toxic agents and clears dead cells.

Astrocytes – maintain a neurons working environment.  Control the levels of neurotransmitters around synapses.  They can modify synapses.

Oligodemdrocytes – provide support to axons of neurons in the central nervous system.

Central Nervous System – Ependymal cells line the spinal cord and ventricles of the brain.  They are involved in creating cerebrospinal fluid.

Radial Glia – Progenitor cells that can generate neurons, astrocytes and oligodendrocytes.

Peripheral Nervous System – Schwann cells myelinate neurons, in the peripheral nervous system.

Satellite Cells – Surround neurons in the sensory, sympathetic and para-sympathetic ganglia and help regulate the chemical environment.

Enteric Glia Cells are found in the nerves of the digestive system.

Types of glia – Queensland Brain Institute, University of Qld, qbi.uq.edu.au>brain-physiology