Increased vertical axon numbers in cingulate cortex of schizophrenics.

Area of Science:

• Neuroscience
• Pathology
• Neuroanatomy

Background:

• Previous studies suggested altered axon numbers in the anterior cingulate cortex (ACC) in schizophrenia.
• A model proposed increased long, vertical, associative axons in the ACC of schizophrenia patients.

Purpose of the Study:

• To test the hypothesis of increased vertical associative axons in the ACC of schizophrenia patients.
• To quantify differences in axon morphology and association in postmortem human cingulate cortex.

Main Methods:

• Immunostaining of human postmortem cingulate cortex using neuron-specific antibodies against the 200-kilodalton neurofilament subunit.
• Manual, blinded counting of axons in layer II and sublamina IIIA.
• Analysis of covariance to control for confounding variables.

Main Results:

• Schizophrenia specimens exhibited 25% more vertical axons than control specimens.
• Significantly higher numbers of long vertical axons (62%) and blood vessel-associated axons (52%) were found in schizophrenia cases.
• No significant difference in large-caliber horizontal axons was observed between groups, indicating a specific increase in vertical axons.

Conclusions:

• Findings support the hypothesis of increased vertical axons in the ACC of schizophrenia patients.
• The observed increase in vertical axons may indicate enhanced associative inputs to the ACC in schizophrenia.
• Further research is needed to determine if these axonal differences are primary or secondary to the disorder.