(C) 2011 Elsevier Ltd. All rights reserved.”
“Recognition systems play a key role in a range of biological processes, including mate choice, immune defence and altruistic behaviour. Social insects provide an excellent model for studying recognition systems because workers need to discriminate between nestmates and non-nestmates, enabling them to direct altruistic behaviour towards closer kin and to repel potential invaders. However, the level of aggression directed learn more towards conspecific intruders can vary enormously, even among workers within the same colony. This is usually

attributed to differences in the aggression thresholds of individuals or to workers having different roles within the colony. Recent evidence from the weaver ant Oecophylla

smaragdina suggests that this does not tell the whole story. Here I propose a new model for nestmate recognition based on a vector template derived from both the individual’s Epigenetic Reader Domain inhibitor innate odour and the shared colony odour. This model accounts for the recent findings concerning weaver ants, and also provides an alternative explanation for why the level of aggression expressed by a colony decreases as the diversity within the colony increases, even when odour is well-mixed. The model makes additional predictions that are easily tested, and represents a significant advance in our conceptualisation of recognition systems. (C) 2010 Elsevier Ltd. All rights reserved.”
“Supraoptic nucleus (SON) neurons secrete either oxytocin or vasopressin into the bloodstream from their axon terminals in the posterior pituitary gland. SON neurons are powerfully inhibited by the classical p-opioid receptor agonist, morphine. Oxytocin neurons develop morphine dependence when chronically exposed to this opiate, and undergo robust withdrawal excitation when morphine is subsequently acutely antagonized by naloxone. Morphine withdrawal excitation Urease is evident as an increased firing rate and

is associated with an increased post-spike excitability that is consistent with the expression of an enhanced post-spike afterdepolarization (ADP) during withdrawal. Here, we used sharp electrode recording from SON neurons in hypothalamic explants from morphine naive and morphine treated rats to determine the effects of morphine on the ADP, and to test the hypothesis that morphine withdrawal increases ADP amplitude in SON neurons. Acute morphine administration (0.05-5.0 mu M) caused a dose-dependent hyperpolarization of SON neurons that was reversed by concomitant administration of 10 mu M naloxone, or by washout of morphine; counter-intuitively, acute exposure to 5 mu M morphine increased ADP amplitude by 78 +/- 11% (mean +/- SEM).