Presence and role of nitric oxide in the central nervous system of the freshwater snail Planorbarius corneus: possible implication in neuron-microglia communication.
The aim of the present study was to investigate the involvement of nitric oxide (NO) as a messenger molecule in neuron-microglia communication in the central nervous system (CNS) of the freshwater snail Planorbarius corneus. The presence of both neuronal (nNOS) and inducible nitric oxide synthase (iNOS) was studied using NADPH-diaphorase (NADPH-d) histochemistry and NOS immunocytochemistry. The experiments were performed on whole ganglia and cultured microglial cells after different activation modalities, such as treatment with lipopolysaccharide and adenosine triphosphate and/or maintaining ganglia in culture medium till 7 days. In sections, nNOS immunoreactivity was found only in neurons and nNOS-positive elements were less numerous than NADPH-d-positive ones, with which they partially overlapped. The iNOS immunoreactivity was observed only after activation, in both nerve and microglial cells. We also found that the number of iNOS-immunoreactive neurons and microglia varied, depending on the activation modalities. In microglial cell cultures, iNOS was expressed in the first generation of cells only after activation, whereas a second generation, proliferated after ganglia activation, expressed iNOS even in the unstimulated condition.
Peruzzi
Elisa
E
Department of Animal Biology, University of Modena and Reggio Emilia, Via Campi 213/D, I-41100 Modena, Italy. peruzzi.elisa@unimore.it
Fontana
Giovanna
G
Sonetti
Dario
D
D000818:Animals; D002450:Cell Communication / Q000502:physiology*; D002490:Central Nervous System / Q000737:chemistry / Q000502:physiology*; D066298:In Vitro Techniques; D017628:Microglia / Q000737:chemistry / Q000502:physiology*; D009474:Neurons / Q000737:chemistry / Q000502:physiology*; D009569:Nitric Oxide / Q000032:analysis / Q000502:physiology*; D012908:Snails / Q000737:chemistry / Q000502:physiology*
D009569:Nitric Oxide