Possible Effects of Synaptic Imbalances on Oligodendrocyte–Axonic Interactions in Schizophrenia: A Hypothetical Model

A model of glial–neuronal interactions is proposed that could be explanatory for the demyelination identified in brains with schizophrenia. It is based on two hypotheses: (1) that glia–neuron systems are functionally viable and important for normal brain function, and (2) that disruption of this postulated function disturbs the glial categorization function, as shown by formal analysis. According to this model, in schizophrenia receptors on astrocytes in glial–neuronal synaptic units are not functional, loosing their modulatory influence on synaptic neurotransmission. Hence, an unconstrained neurotransmission flux occurs that hyperactivates the axon and floods the cognate receptors of neurotransmitters on oligodendrocytes. The excess of neurotransmitters may have a toxic effect on oligodendrocytes and myelin, causing demyelination. In parallel, an increasing impairment of axons may disconnect neuronal networks. It is formally shown how oligodendrocytes normally categorize axonic information processing via their processes. Demyelination decomposes the oligodendrocyte–axonic system making it incapable to generate categories of information. This incoherence may be responsible for symptoms of disorganization in schizophrenia, such as thought disorder, inappropriate affect and incommunicable motor behavior. In parallel, the loss of oligodendrocytes affects gap junctions in the panglial syncytium, presumably responsible for memory impairment in schizophrenia

Outline of an Action-Oriented Classification of Mental Disorders: A Hypothetical Model

The outline of an action-oriented classification of mental disorders is mainly theoretically proposed. Based on the discussion and interpretation of the “Schichtenregel†(three-layer-rule) by the German psychiatrist Karl Jaspers, a synaptic model is elaborated for the pathophysiology of depression, mania and schizophrenia. According to a logic of balance, synapses may be balanced, underbalanced (depression), overbalanced (mania), or unbalanced (schizophrenia). From a psychological point of view, patients with a major depression are hyperintentional, patients with mania are hypointentional, and in the case of schizophrenia they are dysintentional. Decisive in the synaptic model proposed is the number of receptors for neurotransmitters expressed in the membranes of astrocytes. A normal or disturbed balance of behavior can be described as variables of the intentional programs and as values of the description of their feasibility. This enables a computer supported classification of an action-oriented diagnostic manual. The future realization of this procedure may improve psychiatric research and especially clinical practice