The medial nucleus of the amygdala (am) has been implicated in a variety of social behaviors. The present experiment will test the hypothesis that the effect of am lesions on intermale aggressive behavior is due to interference with social learning processes. Small electrolytic lesions of the am had no significant effect in socially naive male rats. A marked reduction of aggressive behavior was...

Systemic and regional hemodynamics were determined with the radioactive microsphere technique either in conscious "sham-lesioned" Wistar rats or after bilateral electrolytic lesions of the nuclei of the anterior hypothalamus. Both mean arterial pressure (111 +/- 4 vs 152 +/- 3 mm Hg) and heart rate (376 +/- 15 vs 504 +/- 12 beats/min) were significantly increased 2 hours after lesioning (p less...

OBJECTIVE The purpose of this study was to retrospectively evaluate and compare the incidence of diffusion-weighted image (DWI) lesions between the Guglielmi detachable coil (GDC) and the Target coil for treating unruptured intracranial aneurysm. METHODS From 2010 to 2011, consecutive 222 patients with an intracranial aneurysm underwent coil embolization. Inclusion criterias were : 1) unruptu...

Rabbits were trained on trace eyeblink (EB) conditioning until they reached a criterion of 10 consecutive EB conditioned responses (CRs). Electrolytic lesions were made in the medial prefrontal cortex (mPFC) centered on the prelimbic area (Brodmann's area 32), at five different intervals after training. These included immediately, 24 h, 1 and 2 weeks, and 1 month after training. Separate groups...

Ascending 5-HT projections from the median raphe nucleus (MRN), probably to the hippocampus, are implicated in the acquisition of contextual fear (background stimuli), as assessed by freezing behavior. Foreground cues like light, used as a conditioned stimulus (CS) in classical fear conditioning, also cause freezing through thalamic transmission to the amygdala. As the MRN projects to the hippo...

1. Noradrenaline, adrenaline and alpha-methylnoradrenaline administration into the nucleus tractus solitarii (NTS) of anaesthetized rats decreased blood pressure and heart rate in a dose-dependent fashion. 2. Bilateral injections were effective in lower doses than unilateral administration. alpha-Methylnoradrenaline given bilaterally produced hypotension in a dose of 0-08 nmol whereas after uni...

In 2 experiments, rats with electrolytic lesions of the dorsal hippocampus and sham-operated control subjects were given injections of lithium chloride after exposure to a distinctive context. This procedure establishes a context-illness association in intact subjects. In Experiment 1, the strength of the context aversion was assessed by measuring the subjects' willingness to consume a novel fl...

The authors compared the effects of pharmacological inactivation of the dorsal hippocampus (DH) or ventral hippocampus (VH) on Pavlovian fear conditioning in rats. Freezing behavior served as the measure of fear. Pretraining infusions of muscimol, a GABAA receptor agonist, into the VH disrupted auditory, but not contextual, fear conditioning; DH infusions did not affect fear conditioning. Prete...

Rats with electrolytic lesions of the ventral tegmental area (VTA, n = 32), or sham lesions (n = 32), were tested in four behavioral paradigms in a shuttlebox. The paradigms were designed to assess the motivational influence of CS-US contiguity and response-reinforcer contingency. The VTA lesion increased the number of shuttle responses in the paradigms involving contiguity between a warning si...

The amygdala and ventral portion of the periaqueductal gray (vPAG) are crucial for the expression of the contextual freezing behavior. However, it is still unclear whether the amygdala also plays a role in defensive behaviors induced by electrical stimulation of the dorsal periaqueductal gray (dPAG). In the present study, rats were implanted with electrodes into dPAG for determination of the th...