T HE EXISTENCE of temperature sensitive regions in the hypothalamus of the cat has been established (1-3). Though capable of controlling thermoregulatory effecters (central control), their relative importance in the unanesthetized animal as compared to the effect of afferent impulses (hereafter called ‘reflex control’), is not so clear. The present experiments were designed to determine a) whet...

Modelling complex social behavior in the laboratory is challenging and requires analyses of dyadic interactions occurring over time in a physically and socially complex environment. In the current study, we approached the analyses of complex social interactions in group-housed male CD1 mice living in a large vivarium. Intensive observations of social interactions during a 3-week period indicate...

The aim of the present study was to find out the changes in sleep-wakefulness and body temperature brought about by application of cholinergic agonist, carbachol, in the medial preoptic area (mPOA). Carbachol, when injected bilaterally into the mPOA of male rats, through chronically implanted cannulae, produced a fall in rectal temperature and long lasting arousal. There was temporal dissociati...

The paper reviews data concerning the involvement of GABA(A) and GABA(B) receptors in the control of GnRH secretion in anestrous ewes. Generally, GABA influences the GnRH release through GABA(A) and GABA(B) receptors located on perikaria of the GnRH neurons in the preoptic area (MPOA) or through the influence on beta-endorphinergic and catecholaminergic systems activity in MPOA and in ventromed...

Sex differences in the size of key limbic nuclei have been found in many species. In some of these species, steroid hormones have been implicated in both the development and the maintenance of the sex difference. However, the possible role of sex-specific genes has not been examined, in part due to lack of an appropriate model system. In this study we measured the size of the ventromedial hypot...

Gonadotropin-releasing-hormone immunopositive (GnRH+) neurons were identified in juvenile and adult male Syrian hamsters. There were significantly fewer GnRH+ cells in the diagonal band of Broca/organum vasculosum of the lamina terminalis (DBB/OVLT) and medial septum (MS) in adults as compared to juvenile males, while no cell number difference was found in the preoptic area (POA). The decrease ...

The preoptic area is a well-established centre for the control of maternal behaviour. An intact medial preoptic area (mPOA) is required for maternal responsiveness because lesion of the area abolishes maternal behaviours. Although hormonal changes in the peripartum period contribute to the initiation of maternal responsiveness, inputs from pups are required for its maintenance. Neurones are act...

Sleep has been hypothesised to maintain a close relationship with metabolism. Here we focus on the brain structure that triggers slow-wave sleep, the ventrolateral preoptic nucleus (VLPO), to explore the cellular and molecular signalling pathways recruited by an increase in glucose concentration. We used infrared videomicroscopy on ex vivo brain slices to establish that glucose induces vasodila...

Our understanding of the brain's functional organisation has greatly benefited from occasional exploratory sessions during electrophysiological studies, trying various manipulations of an animal's environment to trigger responses in particular neurons. Famous examples of such exploration have unveiled various unexpected response properties, such as those of mirror neurons. This approach, which ...

Male reproductive phenotypic plasticity related to environmental-social conditions is common among teleost fish. In several species, males adopt different mating tactics depending on their size, monopolizing mates when larger, while parasitizing dominant male spawns when smaller. Males performing alternative mating tactics are often characterized by a strong dimorphism in both primary and secon...