Mapping the effect of the antisecretory factor on GABA receptor α and α subunits in cerebellar granule cells .

The Antisecretory Factor (AF) is a protein that can reduce intestinal hypersecretion and various inflammation disorders . Discovered in many mammalian tissues and plasma, its mechanism of action remains unknown. Interestingly, its induction has been found to counteract vertigo in patients with Méniere's disease. This suggests an inherent ability to control body balance and posture, an activity that may play a role in cerebellar function. Therefore, it may be worthwhile to investigate whether this activity can inhibit neuronal cells involved in cerebellar circuitries and its potential action on enteric nervous system ganglia, which could explain its antisecretory effect in the intestine. Previously, we studied the role of AF on GABA receptors in cerebellar granule cells, taking advantage of electrophysiology and evaluating the effects of the administration of AF-16, an AF peptide. Treatment with AF-16 increased GABA receptor responses, especially those containing the α subunit. Here, we performed immunofluorescence experiments by staining α and α subunits before and after incubation with AF-16, analyzed super-resolved images comparing pre- and post-treatment maps and critically examined these experimental results with our previous electrophysiological data to shed light on the mechanisms of action of AF protein on GABA receptor subpopulations, specifically the "fast" receptors of α β γ composition that contain either the α or the α subunit. The results indicate that the α subunit is redistributed, with a decrease in neurites and an increase in soma. Conversely, the α subunit shows opposite results, with an increase in neurites and a decrease in soma.