Alterations of the serotonin level in the central nervous system of Locusta migratoria during larval-adult transformation.

Serotonin level was measured in the cerebral, suboesophageal, thoracic and abdominal ganglia of Locusta migratoria during larval-adult transformation. It has been established that the serotonin content shows a progressive increase in the period between the last larval stage and the first 7 days of adult life, being of the highest value in the abdominal ganglia (146%), followed by the thoracic (110%), and then by the cerebral and suboesophageal (75%) ganglia. No significant changes are manifested in the serotonin level in the course of moulting. Considerable increase is also detectable in the protein content of the ganglia during the studied development phase. No correlation is present between the protein and serotonin contents of the ganglia, the changes of the protein content was found to be faster as compared to that of serotonin.