HYPOTHALAMIC neuropeptide Y (NPY) and serotonin (5-HT)-containing neurons are believed to exert an interactive effect on ingestive behavior. The present study examined the ability of two serotonergic antagonists, spiperone (SPIP), a 5-HT2A antagonist, and mianserin (MIAN), a 5-HT2A/2C antagonist, to block the inhibitory action of the 5-HT2A/2C receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) on NPY-stimulated eating. Drugs were injected directly into the paraventricular nucleus (PVN), the perifornical (PFH) or the ventromedial hypothalamus (VMH) at the onset of the dark cycle. PVN, PFH and VMH injections of NPY potentiated food intake although only PVN pretreatment with DOI (5–20 nmol) suppressed NPY-induced eating. SPIP or MIAN, injected immediately prior to PVN DOI, reversed the suppressive effect of DOI on NPY feeding. These findings are consistent with other recent data showing that 5-HT2A receptors within the PVN modulate NPY's effect on food intake at the start of the nocturnal period.

The number, amplitude, duration, and bout structure of isolation-induced ultrasonic vocalization (USV) of infant rats (Rattus norvegicus) were measured on postnatal Day 10. Measurements were made before and after a brief, 1-min, active interaction with their mother or before and after a "pick-up" control procedure. Consistent with prior studies, the number of USVs emitted was significantly increased in the period following the maternal reunion but not after the control procedure. The average amplitude of USVs was also greater following maternal reunion. Finally, analyses characterizing the bout structure of USV production indicated that the average bout size (i.e. number of USVs/bout) was increased severalfold following the reunion with the mother, accounting for the greater rate of USV production during the second isolation period.

Dog and cat preference has been associated with a few factors, like owner personality traits, but data regarding other aspects of preference ontogeny and the impact of preferences on pet wellbeing have yet to be examined. In this exploratory study, several of these characteristics, such as exposure to pets when young and as adults and current pet interactions and diet were analyzed from internet survey data. We found that more people identified as dog people (63.3%) versus cat people (36.7%) and preference for dogs remained consistent from childhood to adulthood compared with cats. In individuals who changed species preference, a lack of childhood exposure to cats (47.2%) was significantly associated with the group that changed preferences from dogs to cats from childhood to adulthood, compared with dog ownership as a child in the group that changed preferences from cats to dogs (24.4%). The number of cats and dogs in the home directly correlated with species preference (p < 0.001). Dwelling location was also significantly associated with species preference, with cat people being more likely to live in an urban area and dog people in a rural area (p = 0.002). More time was spent in both active and passive interactions with pets of the preferred species. Cats owned by cat people were more likely to be fed prescription diets compared with cats owned by dog people (p < 0.001). Interestingly, dog people were more likely to feed both their cats (p = 0.012) and dogs (p < 0.001) a raw diet compared with cat people. Additional research is needed to understand the development and impact of owner species preferences on pets to identify risks of suboptimal wellbeing.