Increased neuronal cell number in the dorsal motor nucleus of the vagus in schizophrenia

Objective: Recently, a reduction in efferent vagal regulation has been found in schizophrenic patients. Methods: Therefore, the brainstems of nine schizophrenic patients and nine normal controls were stereologically analysed. The number of neurons using the optical fractionator method and nuclear volumes applying the Cavalieri principle was estimated in Nissl stained sections of the dorsal motor nucleus of the vagus (DMNV) and the hypoglossal nucleus. Results: The neurons in the right DMNV were significantly increased in the schizophrenic group compared to normal controls (p = 0.047), while the volumes of the DMNV did not differ. In contrast, no such differences were found in the hypoglossal nucleus. Conclusion: Although this pilot study is limited by its small sample size, the analysis of the solitarius-ambiguus-vagus system in schizophrenic patients is an interesting target in schizophrenia research. The most reasonable background for increased neuron numbers in the DMNV could be a system-specific neurodevelopmental disturbance in schizophrenia.