Odor effects were highly heterogeneous and probably be attributed buy AZD8055 to changes in both inhibition and excitation, not to just one or the other. The balance between excitation and inhibition can be tested directly in the future by measuring

synaptic inputs into RSNs and FSNs simultaneously. Although such recordings are still technically challenging, recent improvements in methods like targeted two-photon patch clamp are expected to increase the yield of dual recordings from specific neuronal subtypes even in awake attentive animals (Gentet et al., 2010). Such future experiments may provide insight into the synaptic nature of the cortical changes in spike rates that we report here. Finally, we show that the olfactory-auditory interaction is evident early in the processing stream, as early as A1. However, maternity-induced changes

may still be tracked either earlier or later in the processing stream. For example, changes in responses of thalamic neurons may be a source of an earlier bottom-up effect. Changes in intracortical connectivity or changes in neuronal gene expression patterns may contribute to local plasticity intrinsic to A1. Multisensory Cytoskeletal Signaling inhibitor centers may also be a source of change and induce top-down effects (Schroeder and Foxe, 2005). Indeed, A1 is no longer thought to be a sole unisensory center but rather a multisensory hub (Bizley and King, 2008, Budinger and Scheich, 2009, Musacchia and Schroeder, 2009 and Schroeder and Foxe, 2005). Because there are no known direct

anatomical interactions between early olfactory centers like the olfactory bulb or piriform cortex into A1, functional connectivity is probably relayed indirectly (Musacchia all and Schroeder, 2009). In conclusion, we show that motherhood is associated with a rapid and robust appearance of olfactory-auditory integration in A1 co-occurring with stimulus-specific plasticity to pup distress calls. These uni- and multisensory plastic processes provide substrate for a mechanistic explanation of how changes in neocortical networks facilitate efficient detection of pups by their caring mothers. All experimental procedures used in this study were approved by the Hebrew University Animal Care and Use Committee. Female NMRI mice (total of n = 60 mice, 8–12 weeks old) were anesthetized with ketamine/medetomidine (i.p.; 100 and 83 mg/kg, respectively). Naive virgins are female mice that were never housed with males or pups after they had been weaned at PD21. Lactating mothers are females 4 days after parturition (PD4 ± 12 hr), nursing a litter of at least five pups. Depth of anesthesia was monitored by the pinch withdrawal reflex and ketamine/medetomidine was added to maintain it. Dextrose-saline was injected subcutaneously to prevent dehydration. Rectal temperature (36°C ± 1°C) was monitored continuously. In five animals, we also monitored the heart rate and/or the breathing rate.