EN
Our previous studies revealed an overlap of cholinergic and NO-ergic preganglionic neurons in the autonomic sympathetic and parasympathetic spinal cord nuclei of the pig. A close topographical as well as morphological relationship between both neuronal populations suggests a possible co-expression of the ChAT and NOS in the same autonomic neurons. Therefore, the goal of the present study was to determine the correlation between the ChAT- and neuronal NOS-immunoreactivity in the thoracic intermediolateral and sacral intermediolateral and intermediomedial nuclei. Double immunocytochemical staining revealed that many of the ChAT positive cell bodies demonstrated immunoreactivity to NOS. The number of the double stained cell bodies depended on the cross-section level. In the intermediolateral nucleus of the thoracic spinal cord about 60% of the ChAT-positive cells co- expressed also NOS, while in the intermediolateral nucleus of the S2 spinal segment constituted approximately 52%. The colocalisation of both substances in the intermediomedial nucleus varied from 39% at SI level until 58% at S2 spinal plane. Our data provide morphological evidence confirming the co-expression of NOS in the spinal sympathetic and parasympathetic cholinergic neurons and suggest that NO may play a role in the modulation of the spinal cholinergic transmission.