Previous research has demonstrated that the nervous system may exert a significant impact on lymphocyte distribution and function in certain mucosal tissues. Given this neural-immune interaction, the present study was designed to evaluate whether ocular nerves might influence the distribution, density, and output of IgA-containing cells in the lacrimal gland. Male Sprague-Dawley rats were subjected to one of the following surgical protocols: denervation of the temporofacial, optic, or trigeminal nerves or ablation of the superior cervical ganglion. Denervations were performed on one side and sham-operations on the contralateral side. Additional groups of rats were exposed to bilateral sham or complete optic nerve disruption. Two to four weeks after surgery, tears were collected from individual eyes for the measurement of IgA and protein levels and lacrimal glands were processed for the immunofluorescent identification of IgA-containing cells. Our results showed that a marked heterogeneity is present in the frequency distribution of IgA-containing cells in lacrimal tissue sections of sham-operated rats. Statistical analysis of this distribution showed that the topographical location of IgA-containing cells per section or through the gland was not random. This heterogeneity did not appear to be modified by interrupting various nerves to the eye. Moreover, severance of the temporofacial, optic, or trigeminal nerve supplies or extirpation of the superior cervical ganglion did not significantly alter either the density or total number of IgA-containing cells in the lacrimal gland, as compared to values in contralateral "sham-operated" tissues. In addition, these neural disruptions had no apparent influence on the IgA content or the IgA/protein ratio in tears.(ABSTRACT TRUNCATED AT 250 WORDS)