Pathologic axons and synapses in human neuropsychiatric disorders

Area of Science:

• Neurobiology
• Neuropathology

Background:

• Psychomotor retardation and dementia involve pathological changes in brain structures.
• Axonal and synaptic abnormalities are observed in affected patients.

Purpose of the Study:

• To review clinical disorders associated with axonal and presynaptic terminal lesions.
• To identify basic ultrastructural abnormalities in cerebral biopsy specimens.

Main Methods:

• Ultrastructural analysis of cerebral biopsy specimens.
• Review of clinical disorders with lesions in axons and presynaptic terminals.
• Golgi method for observing neuronal structures.

Main Results:

• Detected three basic abnormalities: proliferation of tubulovesicular structures, abnormal mitochondria, and filament proliferation.
• Observed abnormal dendritic spines in cortical neurons in some mental retardation cases, attributed to dysgenesis.
• Identified pathological changes in axons and presynaptic/postsynaptic processes.

Conclusions:

• Understanding pathogenesis requires advances in membrane biology, neurotransmitter secretion, axoplasmic flow, and fibrous protein functions.
• Current ultrastructural knowledge is incomplete, necessitating future neurobiology developments for primary phenomenon identification.