What is a leading hypothesis of schizophrenia?

The glutamate and dopamine hypotheses are leading theories of the pathoaetiology of schizophrenia. Both were initially based on indirect evidence from pharmacological studies supported by post-mortem findings, but have since been substantially advanced by new lines of evidence from in vivo imaging studies.

What is NMDA hypothesis?

The N-methyl-d-aspartate receptor (NMDAR) hypofunction hypothesis has been proposed to help understand the etiology and pathophysiology of schizophrenia. This hypothesis was based on early observations that NMDAR antagonists could induce a full range of symptoms of schizophrenia in normal human subjects.

What contributes to the glutamate hypothesis schizophrenia?

The glutamate hypothesis of schizophrenia originates from the effect of NMDA receptor blockers (ketamine, phencyclidine), which produce a withdrawn, passive state that resembles the ‘negative’ symptoms of schizophrenia (passivity and anhedonism).

What is the original dopamine hypothesis of schizophrenia?

The “original dopamine hypothesis” states that hyperactive dopamine transmission results in schizophrenic symptoms. This hypothesis was formed upon the discovery of dopamine as a neurotransmitter in the brain by Arvid Carlsson (6–12).

What is the neurodevelopmental hypothesis of schizophrenia?

The influential neurodevelopmental hypothesis of schizophrenia proposes that pathological neurodevelopmental processes, beginning as early as the first and second trimesters, result in neuronal circuits that are primed to generate psychotic symptoms during adolescence or young adulthood, often in the context of …

What is serotonin hypothesis?

The “serotonin hypothesis” of clinical depression is almost 50 years old. At its simplest, the hypothesis proposes that diminished activity of serotonin pathways plays a causal role in the pathophysiology of depression.

Does high serotonin cause schizophrenia?

Compared with healthy subjects, schizophrenic patients may also have increased levels of serotonin and decreased levels of norepinephrine in the brain.

What is the NMDA hypofunction hypothesis of schizophrenia?

What is the role of glutamate in addiction?

More recently, it has been realized that glutamate also plays a central role in processes underlying the development and maintenance of addiction. These processes include reinforcement, sensitization, habit learning and reinforcement learning, context conditioning, craving and relapse.

What is excitotoxicity?

Excitotoxicity can occur from substances produced within the body ( endogenous excitotoxins). Glutamate is a prime example of an excitotoxin in the brain, and it is also the major excitatory neurotransmitter in the central nervous system of mammals.

What is the pathophysiology of ischemia and excitotoxicity?

Ischemia is followed by accumulation of glutamate and aspartate in the extracellular fluid, causing cell death, which is aggravated by lack of oxygen and glucose. The biochemical cascade resulting from ischemia and involving excitotoxicity is called the ischemic cascade.

What is schizophrenia?

Key facts Schizophrenia is a chronic and severe mental disorder affecting more than 21 million people worldwide. Schizophrenia is characterized by distortions in thinking, perception, emotions, language, sense of self and behaviour.

How is hypoglycemia treated in patients in excitotoxic shock?

Persons in excitotoxic shock must never fall into hypoglycemia. Patients should be given 5% glucose (dextrose) IV drip during excitotoxic shock to avoid a dangerous build up of glutamate around NMDA and AMPA neurons. When 5% glucose (dextrose) IV drip is not available high levels of fructose are given orally.