Empathy and the art of Leonardo da Vinci.

Knowledge about empathy is part of the study of artistic expressions, among which stand out works of personalities such as the Renaissance polymath Leonardo da Vinci, who was concerned with the connection between science and art during his creative research full of imagination and sensitivity to nature and human anatomy. The word empathy emerged among critics of German art as the term , which was used within the aesthetic bias by philosophers and art historians. It emphasized the idea that a viewer perceiving an object could establish a link between it and themselves, projecting the object 'into themselves'.

Ingestive and locomotor behaviours induced by pharmacological manipulation of -adrenoceptors into the median raphe nucleus.

The present study evaluated the involvement of α-adrenoceptors of the median raphe nucleus (MRN) in satiated rats, in food and water intake and motor behaviour. Control groups were treated with saline (SAL) or adrenaline (ADR), injected into the MRN seven minutes after injection of the vehicle used to solubilize the antagonists, propylene glycol (PLG) or SAL. Experimental groups were treated with an α-adrenoceptor antagonist, prazosin (α1, 20 or 40 nmol) or yohimbine (α2, 20 or 40 nmol) or phentolamine (non-selective α, 20 or 40 nmol), followed (later) by injection of ADR or SAL.

Alpha1 receptor antagonist in the median raphe nucleus evoked hyperphagia in free-feeding rats.

Serotonergic neurons in the median raphe nucleus (MnR) are stimulated by α(1)-adrenergic agonists and inhibited by α(2)-agonists. This study investigated the effect of the blockade of the MnR α(1)-adrenergic receptors of free feeding rats as an attempt to elucidate the functional role of these receptors in the control of feeding behavior. In addition, an α(2)-receptor antagonist was also administered in the MnR in order to strengthen the previous suggestion that α(2)-adrenergic receptors participate in the control of feeding behavior, probably decreasing the facilitatory influence on MnR serotonergic neurons.

Phenylephrine into the median raphe nucleus evokes an anxiolytic-like effect in free-feeding rats but does not alter food intake in free feeding rats.

This study investigated the role of MnR α₁-adrenergic receptors in the control of anxiety-like and feeding behaviors and attempted to reveal a possible functional association between both behaviors. The α₁-adrenergic agonist phenylephrine (PHE) (at doses of 0.2, 2, 6, 20 nmol) or saline was injected into the MnR or into the pontine nucleus (Pn) of free-feeding rats.

Changes in food intake and anxiety-like behaviors after clonidine injected into the median raphe nucleus.

Serotonergic neurons in the median raphe nucleus (MnR) are stimulated by alpha(1)-adrenergic agonists and inhibited by alpha(2) agonists. This study investigated the participation of MnR alpha(2)-adrenergic receptors in the control of anxiety-like behavior and feeding as an attempt to establish a functional association between these behaviors. The alpha(2)-adrenergic agonist clonidine (CLON) was injected into the MnR (0, 0.

Food intake increased after injection of adrenaline into the median raphe nucleus of free-feeding rats.

The present study examined the effects of local injections of adrenaline (AD) or noradrenaline (NA) in equimolar doses (6, 20, and 60 nmol) into the median raphe nucleus (MRN) on ingestive and non-ingestive behaviors of free-feeding rats. The results showed that the treatment with AD at doses of 20 and 60 nmol increased food intake. While the hyperphagic response evoked by 60 nmol dose of AD was accompanied by a reduction of the latency to start feeding and an increase in the frequency of feeding, the 20 nmol dose of AD was unable to change these behavioral aspects of feeding response.