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Connections between the central posterior/prepacemaker nucleus and hypothalamic areas in the weakly electric fish Apteronotus leptorhynchus : Evidence for an indirect, but not a direct, link
Author(s) -
Corrêa Sônia A.L.,
Zupanc Günther K.H.
Publication year - 2001
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.10103
Subject(s) - electric fish , neuroscience , biology , hypothalamus , electroreception , nucleus , thalamus , anterograde tracing , fish <actinopterygii> , sensory system , fishery
The central posterior/prepacemaker nucleus (CP/PPn) of the weakly electric fish Apteronotus leptorhynchus consists of a few thousands of neurons in the dorsal thalamus. Subpopulations of this complex play a crucial role in neural control of transient modulations of the otherwise extremely constant electric organ discharges. Because both the propensity to execute these modulations and the type of modulations produced may vary enormously with the behavioral situation, it has been hypothesized that this behavioral plasticity is, partially, mediated by peptidergic neuromodulators originating from hypothalamic areas. To define the structural basis of this proposed modulatory input, we have in the present study examined the connections between the CP/PPn proper and hypothalamic areas by employing an in vitro tract‐tracing technique. Neither anterograde nor retrograde tracing experiments could provide evidence for the existence of a direct link between the CP/PPn proper and hypothalamic areas. However, the results of our investigation suggest an indirect connection between the CP/PPn proper and two hypothalamic regions, the hypothalamus ventralis and the hypothalamus lateralis, with the preglomerular nucleus serving as a relay station. J. Comp. Neurol. 442:348–364, 2002. © 2002 Wiley‐Liss, Inc.