Interactions of endogenous lectin from the Helix pomatia reproductive system (HPA) with the surface of CNS neurons of the snail

The surface of unidentified cultured neurons and electrophysiologically identified units RPa1, RPa2, and LPa3 of the snell Helix pomatia was studied using a colloidal gold-labelled endogenous gonad lectin of this mollusc (Helix pomatia agglutinin - HPA), which is specific to alpha-anomer N-acetyl-D-galactosamine, and some other lectins. It was found that only two populations of cultured neurons with a specific ultrastructure typical of peptidergic cells and differing from the ultrastructure of other peptidergic and non-peptidergic neurons possess HPA receptors. These neurons average about 1% of cultured nerve cells. Using I variety of plant lectins with HPA-like specificity (LBA, VVA, SEA) showed that the surface of many peptidergic neurons contains alpha-anomer-like structures, yet ii does not bind HPA. These data were supported in the experiments on identified snail neurons with the use of SEA. The results suggest a putative role of endogenous lectins in regulation of activity of neurons participating in processes of secretion in the gonads.