OCCURRENCE AND DISTRIBUTION OF INSULIN RECEPTOR-LIKE IMMUNOREACTIVITYIN MOLLUSCAN BRAINS

Insulin receptor-like immunoreactivity (IR) was investigated in the ce ntral ganglia of different gastropod molluscs using a monoclonal antis erum raised against an epitope of the human placental insulin receptor . A well detectable and clear location of immunoreactive material was mainly found in the CNS of the freshwater snails Planorbarius corneus and Lymnaea stagnalis. This evidence correlates quite suggestively wit h the occurrence in these snails of a molluscan insulin peptide (MIP) previously shown. The widespread and discrete distribution of IR over a variety of physiologically distinct regions of P. corneus and L. sta gnalis ganglia argues that these ''receptors'' may modulate multiple f unctions within the CNS.