Species differences in the coexistence of 5-hydroxytryptamine and substance P in presynaptic boutons in the cervical ventral horn.
Substance P (SP)- and 5-hydroxytryptamine (5-HT)-containing presynaptic boutons in the cervical ventral horn were studied in chicken, hamster, rat and monkey spinal cords, using PAP and protein A-gold double-labeling techniques in conjunction with monoclonal antibodies. In the chicken, the PAP method demonstrated that SP-immunoreactive boutons contained large spherical dense-cored vesicles (DCVs) whereas 5-HT-immunoreactive boutons displayed both elongated and spherical DCVs. Using the protein A-gold double-labeling technique, 10-nm gold particles for SP were localized over the spherical DCV-containing boutons whereas 15-nm gold particles for 5-HT were localized on elongated DCV-containing boutons. On the other hand, in the other species investigated, both SP- and 5-HT-immunoreactive boutons had similar morphological features as shown by the PAP method; both contained elongated and spherical DCVs. The two different sized gold particles, each of which labeled either 5-HT or SP, were found together over DCVs in a single bouton. These results indicate that 5-HT and SP are contained in different presynaptic boutons in the chicken, although in the hamster, rat and Japanese macaque, the two neurotransmitters/modulators coexist in the same DCVs in a single bouton. Species differences have thus been demonstrated for the coexistence of 5-HT and SP in the spinal ventral horn.
Sakamoto
H
H
Department of Anatomy, Yamanashi Medical College, Japan.
Atsumi
S
S
D000818:Animals; D006224:Cricetinae; D005260:Female; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008251:Macaca; D008297:Male; D008647:Mesocricetus; D008854:Microscopy, Electron; D051381:Rats; D012701:Serotonin / Q000378:metabolism*; D013045:Species Specificity; D013116:Spinal Cord / Q000378:metabolism* / Q000648:ultrastructure; D013373:Substance P / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism
D012701:Serotonin; D013373:Substance P