Activation of a heterologously expressed octopamine receptor coupled only to adenylyl cyclase produces all the features of presynaptic facilitation in Aplysia sensory neurons

Citation
Dj. Chang et al., Activation of a heterologously expressed octopamine receptor coupled only to adenylyl cyclase produces all the features of presynaptic facilitation in Aplysia sensory neurons, P NAS US, 97(4), 2000, pp. 1829-1834
Citations number
34
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Multidisciplinary
Journal title
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
ISSN journal
0027-8424 → ACNP
Volume
97
Issue
4
Year of publication
2000
Pages
1829 - 1834
Database
ISI
SICI code
0027-8424(20000215)97:4<1829:AOAHEO>2.0.ZU;2-#
Abstract
Short-term behavioral sensitization of the gill-withdrawal reflex after tai l stimuli in Aplysia leads to an enhancement of the connections between sen sory and motor neurons of this reflex. Both behavioral sensitization and en hancement of the connection between sensory and motor neurons are important ly mediated by serotonin. Serotonin activates two types of receptors in the sensory neurons, one of which is coupled to the cAMP/protein kinase A (PKA ) pathway and the other to the inositol triphosphate/ protein kinase C (PKC ) pathway. Here we describe a genetic approach to assessing the isolated co ntribution of the PKA pathway to short-term facilitation. We have cloned fr om Aplysia an octopamine receptor gene, Ap oa(1), that couples selectively to the cAMP/PKA pathway. We have ectopically expressed this receptor in Apl ysia sensory neurons of the pleural ganglia, where it is not normally expre ssed. Activation of this receptor by octopamine stimulates all four presyna ptic events involved in short-term synaptic facilitation that are normally produced by serotonin: (i) membrane depolarization;(ii) increased membrane excitability; (iii) increased spike duration; and (iv) presynaptic facilita tion. These results indicate that the cAMP/PKA pathway alone is sufficient to produce all the features of presynaptic facilitation.