Long-term exposure to histamine induces the expression of an embryonic-like motor pattern in an adult nervous system
European Journal of Neuroscience. 2007-11-14; 26(11): 3181-3192
DOI: 10.1111/j.1460-9568.2007.05944.x
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Sullivan JM(1), Faumont S, Ducret E, Le Feuvre Y, Fénelon VS, Meyrand P.
Author information:
(1)Laboratoire de Neurobiologie des Réseaux, Université Bordeaux I & Centre
Nationale de la Recherche Scientifique, Unité Mixte de Recherche 5816, Avenue des
Facultés, 33405 Talence cedex, France.
Neuromodulatory inputs play important roles in shaping the outputs of neural
networks. While the actions of neuromodulatory substances over the short term
(seconds, minutes) have been examined in detail, far less is known about the
possible longer-term (hours) effects of these substances. To investigate this
issue, we used the stomatogastric nervous system (STNS) of the lobster to examine
the short- and long-term effects of histamine on rhythmic network activity. The
application of histamine to the entire STNS had strong inhibitory effects on all
three of the STNS networks, observable within minutes. In contrast, longer-term
(> 1 h) application of histamine induced the expression of a single, unified
rhythm involving neurons from all three networks. Selective application of
histamine to different regions of the STNS demonstrated that a unified rhythm
arises following the long-term application of histamine to the commissural
ganglia (CoGs; modulatory centres), but not the stomatogastric ganglion (site of
neural networks). Strikingly, the single rhythm observed following the long-term
application of histamine to the CoGs exhibits many similarities with the single
rhythm expressed by the embryonic STNS. Together, these results demonstrate that
histamine has markedly different short- and long-term effects on network
activity; short-term effects arising through direct actions on the networks and
long-term effects mediated by actions on modulatory neurons. Furthermore, they
indicate that histamine is able to induce the expression of an embryonic-like
rhythm in an adult system, suggesting that long-term actions of histamine may
play key roles in the development of the STNS networks.
DOI: 10.1111/j.1460-9568.2007.05944.x
PMID: 18005056 [Indexed for MEDLINE]