Role of the rostral dorsomedial column of the periaqueductal gray during social defeat in rats.

Previous studies showed that the dorsal premammillary nucleus of the hypothalamus (PMD) is involved in social passive defensive behaviors likely to be meditated by descending projections to the periaqueductal gray (PAG). We focused on the rostral dorsomedial PAG (rPAGdm) to reveal its putative neural mechanisms involved in mediating social defensive responses. By combining retrograde tracing and FOS expression analysis, we showed that in addition to the PMD, the rPAGdm is influenced by several brain sites active during social defeat.

Sexually dimorphic responses of rats to fluoxetine in the forced swimming test are unrelated to the function of the serotonin transporter in the brain.

Due to the prevalence of depression in women, female rats may be a better models for antidepressant research than males. In male rats, fluoxetine inhibited the serotonin (5-hydroxytryptamine, 5-HT) transporter (SERT) which is reducing the immobility time in the repeated forced swimming test (rFST). The performance of female rats in this test is unknown.

Expression of aggressiveness modulates mesencephalic c-fos activation during a social interaction test in Japanese quail (Coturnix japonica).

It is well known that during a social conflict, interactions are dependent on the animal's propensity to behave aggressively as well as the behavior of the opponent. However, discriminating between these two confounding factors was difficult. Recently, a Social Interaction (SI) test using photocastrated males as non-aggressive stimuli was proposed as a useful tool to evaluate aggressiveness.

Antidepressant and pro-neurogenic effects of agmatine in a mouse model of stress induced by chronic exposure to corticosterone.

Agmatine is an endogenous neuromodulator that has been shown to have beneficial effects in the central nervous system, including antidepressant-like effects in animals. In this study, we investigated the ability of agmatine (0.1mg/kg, p.

The mesencephalic GCt-ICo complex and tonic immobility in pigeons (Columba livia): a c-Fos study.

Tonic immobility (TI) is a response to a predator attack, or other inescapable danger, characterized by immobility, analgesia and unresponsiveness to external stimuli. In mammals, the periaqueductal gray (PAG) and deep tectal regions control the expression of TI as well as other defensive behaviors. In birds, little is known about the mesencephalic circuitry involved in the control of TI.

Distribution of serotonin 5-HT1A-binding sites in the brainstem and the hypothalamus, and their roles in 5-HT-induced sleep and ingestive behaviors in rock pigeons (Columba livia).

Serotonin 1A receptors (5-HT1ARs), which are widely distributed in the mammalian brain, participate in cognitive and emotional functions. In birds, 5-HT1ARs are expressed in prosencephalic areas involved in visual and cognitive functions. Diverse evidence supports 5-HT1AR-mediated 5-HT-induced ingestive and sleep behaviors in birds.

Stress-induced core temperature changes in pigeons (Columba livia).

Changes in body temperature are significant physiological consequences of stressful stimuli in mammals and birds. Pigeons (Columba livia) prosper in (potentially) stressful urban environments and are common subjects in neurobehavioral studies; however, the thermal responses to stress stimuli by pigeons are poorly known. Here, we describe acute changes in the telemetrically recorded celomatic (core) temperature (Tc) in pigeons given a variety of potentially stressful stimuli, including transfer to a novel cage (ExC) leading to visual isolation from conspecifics, the presence of the experimenter (ExpR), gentle handling (H), sham intracelomatic injections (SI), and the induction of the tonic immobility (TI) response.