Show simple item record

dc.contributor.authorKeating, Christopher
dc.contributor.authorLloyd, Philip
dc.identifier.citationKeating , C & Lloyd , P 1999 , ' Differential modulation of motor neurons that innervate the same muscle but use different excitatory transmitters in Aplysia ' , Journal of Neurophysiology , vol. 82 , no. 4 , pp. 1759-1767 . < >
dc.identifier.otherPURE: 2077041
dc.identifier.otherPURE UUID: 6c7d9fd0-6a2a-40e7-b6e5-10e1fc73f34d
dc.identifier.otherScopus: 0032859564
dc.description.abstractThe medial portion of intrinsic buccal muscle 3 (I3m) is innervated by two excitatory motor neurons, B3 and B9. B3 uses glutamate as its fast transmitter and expresses the neuropeptide FMRFamide, whereas B9 uses acetylcholine as its fast transmitter and expresses the neuropeptide SCP. This preparation was used to study peptidergic modulation of muscles innervated by neurons that use different fast excitatory transmitters. First, we determined the effects of the application of the neuropeptides expressed in these neurons on excitatory junction potentials (EJPs) and contractions. FMRFamide increased the amplitude of EJPs and contractions evoked by B3 while decreasing those evoked by B9. This is the first observation in buccal muscle of a substance that modulates two excitatory neurons innervating the same muscle in opposite directions. SCP increased EJPs contraction amplitude, and the rate of muscle relaxation for both motor neurons. We determined that SCP potently increased cAMP levels in I3m as it does in other buccal muscles. Stimulation of B9 also caused increased cAMP levels in I3m providing independent evidence for SCP release. Finally, stimulation of B9 increased both the contraction amplitude and relaxation rate of B3-evoked I3m contractions in a manner similar to that observed using exogenous SCP. By inhibiting B9’s cholinergic transmission with an antagonist, we were able to observe modulatory effects of B9 in the absence of fast excitatory effects. We found that the magnitude of the modulation was dependent on the firing frequency and did occur at frequencies and patterns of firing recorded previously for B9 during ingestive-like motor programsen
dc.relation.ispartofJournal of Neurophysiology
dc.titleDifferential modulation of motor neurons that innervate the same muscle but use different excitatory transmitters in Aplysiaen
dc.contributor.institutionSchool of Life and Medical Sciences
dc.contributor.institutionDepartment of Human and Environmental Sciences
dc.contributor.institutionHealth & Human Sciences Research Institute
dc.contributor.institutionPharmacology and Clinical Science Research
dc.contributor.institutionAgriculture, Food and Veterinary Sciences
dc.description.statusPeer reviewed
rioxxterms.typeJournal Article/Review

Files in this item


There are no files associated with this item.

This item appears in the following Collection(s)

Show simple item record