TY - JOUR
T1 - Neurokinin-1 receptor localisation in guinea pig autonomic ganglia
AU - Messenger, Jennifer P.
AU - Anderson, Rebecca L.
AU - Gibbins, Ian L.
PY - 1999/10/4
Y1 - 1999/10/4
N2 - We have used multiple-labelling immunohistochemistry and confocal microscopy to determine the distribution of immunoreactivity to the tachykinin neurokinin-1 (NK1) receptors in guinea pig sympathetic ganglia. Although nerve fibres containing immunoreactivity to substance P were common in all ganglia except the superior cervical ganglia, most neurons expressing NK1 receptor immunoreactivity were not closely surrounded by pericellular baskets of substance P-immunoreactive boutons. Conversely, many neurons surrounded by baskets of substance P-immunoreactive boutons lacked NK1 immunoreactivity. In the coeliac and inferior mesenteric ganglia, NK1 receptor expression was restricted almost entirely to noradrenergic neurons that contained somatostatin immunoreactivity and projected to the enteric plexuses. In the lumbar chain and paracervical ganglia, NK1 immunoreactivity was expressed by nonnoradrenergic vasodilator neurons containing immunoreactivity to vasoactive intestinal peptide. Taken together, our results show that sympathetic neurons in different functional pathways express NK1 receptor immunoreactivity. However, the neurons that could respond to endogenously released substance P through NK1 receptors may be distant from presynaptic release sites. These observations suggest that, in sympathetic ganglia, substance P may modulate ganglionic transmission through heterosynaptic actions on NK1 receptors.
AB - We have used multiple-labelling immunohistochemistry and confocal microscopy to determine the distribution of immunoreactivity to the tachykinin neurokinin-1 (NK1) receptors in guinea pig sympathetic ganglia. Although nerve fibres containing immunoreactivity to substance P were common in all ganglia except the superior cervical ganglia, most neurons expressing NK1 receptor immunoreactivity were not closely surrounded by pericellular baskets of substance P-immunoreactive boutons. Conversely, many neurons surrounded by baskets of substance P-immunoreactive boutons lacked NK1 immunoreactivity. In the coeliac and inferior mesenteric ganglia, NK1 receptor expression was restricted almost entirely to noradrenergic neurons that contained somatostatin immunoreactivity and projected to the enteric plexuses. In the lumbar chain and paracervical ganglia, NK1 immunoreactivity was expressed by nonnoradrenergic vasodilator neurons containing immunoreactivity to vasoactive intestinal peptide. Taken together, our results show that sympathetic neurons in different functional pathways express NK1 receptor immunoreactivity. However, the neurons that could respond to endogenously released substance P through NK1 receptors may be distant from presynaptic release sites. These observations suggest that, in sympathetic ganglia, substance P may modulate ganglionic transmission through heterosynaptic actions on NK1 receptors.
KW - Heterosynaptic transmission
KW - Substance P
KW - Sympathetic
KW - Tachykinin
UR - http://www.scopus.com/inward/record.url?scp=0033523627&partnerID=8YFLogxK
U2 - 10.1002/(SICI)1096-9861(19991004)412:4<693::AID-CNE10>3.0.CO;2-T
DO - 10.1002/(SICI)1096-9861(19991004)412:4<693::AID-CNE10>3.0.CO;2-T
M3 - Article
C2 - 10464364
AN - SCOPUS:0033523627
SN - 0021-9967
VL - 412
SP - 693
EP - 704
JO - Journal of Comparative Neurology
JF - Journal of Comparative Neurology
IS - 4
ER -