Localisation of substance P immunoreactivity in amacrine cells of the retina.
Since its actions on smooth muscle were first described by von Euler and Gaddum, substance P has been isolated and characterised as an undecapeptide. The distribution of substance P-like immunoreactivity in both the central and peripheral nervous systems and its reported excitatory action on neurones implicate substance P as a possible neurotransmitter and/or neuromodulator. Previous studies using bioassay and radioimmunoassay techniques have reported substance P in retinal extracts. Here we describe the specific immunohistochemical localisation of substance P-like immunoreactivity in a population of morphologically distinct amacrine cells of the pigeon retina. The localisation of substance P-like immunoreactivity and the recent localisation of enkephalin-like and somatostatin-like immunoreactivity in other types of amacrine cells suggest that the neuropeptides have a specific role in retinal function.
D000818:Animals; D000918:Antibody Specificity; D010856:Columbidae; D004745:Enkephalins / Q000276:immunology / Q000378:metabolism; D007158:Immunologic Techniques; D012160:Retina / Q000166:cytology / Q000378:metabolism*; D013373:Substance P / Q000276:immunology / Q000378:metabolism*
D004745:Enkephalins; D013373:Substance P