1. Academic Validation
  2. The satiety signaling neuropeptide perisulfakinin inhibits the activity of central neurons promoting general activity

The satiety signaling neuropeptide perisulfakinin inhibits the activity of central neurons promoting general activity

  • Front Cell Neurosci. 2007 Dec 30;1:3. doi: 10.3389/neuro.03.003.2007.
Dieter Wicher 1 Christian Derst Hélène Gautier Bruno Lapied Stefan H Heinemann Hans-Jürgen Agricola
Affiliations

Affiliation

  • 1 Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology Germany. dwicher@ice.mpg.de
Abstract

The metabolic state is one of the determinants of the general activity level. Satiety is related to resting or sleep whereas hunger correlates to wakefulness and activity. The counterpart to the mammalian satiety signal cholecystokinin (CCK) in insects are the sulfakinins. The aim of this study was to resolve the mechanism by which the antifeedant activity of perisulfakinin (PSK) in Periplaneta americana is mediated. We identified the sources of PSK which is used both as hormone and as paracrine messenger. PSK is found in the neurohemal organ of the brain and in nerve endings throughout the central nervous system. To correlate the distributions of PSK and its receptor (PSKR), we cloned the gene coding for PSKR and provide evidence for its expression within the nervous system. It occurs only in a few neurons, among them are the dorsal unpaired median (DUM) neurons which release octopamine thereby regulating the general level of activity. Application of PSK to DUM neurons attenuated the spiking frequency (EC(50)=11pM) due to reduction of a pacemaker CA(2+) current through cAMP-inhibited pTRPgamma channels. PSK increased the intracellular cAMP level while decreasing the intracellular CA(2+) concentration in DUM neurons. Thus, the satiety signal conferred by PSK acts antagonistically to the hunger signal, provided by the adipokinetic hormone (AKH): PSK depresses the electrical activity of DUM neurons by inhibiting the pTRPgamma channel that is activated by AKH under conditions of food shortage.

Keywords

Ca2+ channel; DUM neuron; Periplaneta; RF-amide; TRPγ channel; neuropeptide; perisulfakinin; volume transmission.

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