Relationship between pain and anxiety in rats

Clinically, it is well known that neuropathic pain often induces comorbid symptoms such as anxiety. In turn, also anxiety has been associated with a heightened experience of pain. Although, the link between pain and anxiety is well recognized in humans, the neurobiological basis of this relationship remains unclear. Therefore, the aim of the current study was to investigate the influence of neuropathic pain on anxiety and vice versa in rats by assessing not only pain-related behaviour but also by discovering possible key substrates which are responsible for the interrelation of pain and anxiety.rnIn rats with a chronic constriction of the sciatic nerve (CCI model) anxiety-like behaviour was observed. Since anxiety behaviour could be completely abolished after the treatment of the pure analgesic drugs gabapentin and morphine, we concluded that anxiety was caused by the strong persistent pain. Furthermore, we found that the neuropeptides oxytocin and vasopressin were upregulated in the amygdala of CCI rats, and the intra-amygdala treatment of an oxytocin antagonist but not the vasopressin antagonist could reduce anxiety-like behaviour in these animals, while no effect on mechanical hypersensitivity was observed. These data indicate that oxytocin is implicated in the underlying neuronal processes of pain-induced anxiety and helps to elucidate the pathophysiological mechanisms of neuropathic pain. rnTo assess the influence of trait anxiety on pain sensation in rats, we determined mechanical hypersensitivity after sciatic nerve lesion (CCI) in animals selectively bred for high anxiety or low anxiety behaviour. The paw withdrawal thresholds were significantly decreased in high anxiety animals in comparison to low anxiety animals 2 and 3 weeks after surgery. In a second model state anxiety was induced by the sub-chronic injection of the anxiogenic drug pentylentetrazol in naive rats. Pain response to mechanical stimuli was increased after pharmacologically-induced anxiety. These results provided evidence for the influence of both trait and state anxiety on pain sensation. rnThe studies contribute to the elucidation of the relationship between pain and anxiety. We investigated that the neuropathic pain model displays sensory as well as emotional factors of peripheral neuropathy. Changes in expression levels of neuropeptides in the central nervous system due to neuropathic pain may contribute to the pathophysiology of neuropathic pain and its related symptoms in animals which might also be relevant for human scenarios. The results of the current study also confirm that anxiety plays an important role in the perception of pain. rnA better understanding of pain behaviour in animals might improve the preclinical profiling of analgesic drugs during development. The study highlights the potential use of the rat model as a new preclinical tool to further investigate the link between pain and anxiety by determining not only the sensory reflexes after painful stimuli but also the more complex pain-related behaviour such as anxiety.rn

Schmerz und Angst sind bei Kindern besonders zu berücksichtigen

Bei Kindern heilen Wunden wie beim Erwachsenen in verschiedenen Phasen ab. Insbesondere beim jüngeren Kind erfolgt die Wundheilung tendenziell schneller und komplikationsarmer. Es stehen rascher Fibroblasten zur Verfügung und Granula­tionsgewebe wird schneller produziert. Kinder verfügen über weniger subkutanes Fettgewebe und haben somit einen geringeren «Totraum», welchem in der Entstehung von Infektionen eine Rolle zugeschrieben wird. Allgemein verfügen Kinder über ein funktionierendes Gefässsystem und leiden an anderen ­Komorbiditäten als Erwachsene. Diese Faktoren tragen dazu bei, dass Wunden in der Pädiatrie in der Regel primär (Sanatio per primam intentionem) heilen.

Acknowledging, moving toward and transcending psychophysiological angst during a paradox of conflicting desires

In this paper I integrate the work of a number of philosophers to clarify some psychological issues that can arise in human existence when a conflict of intrapersonal or interpersonal desires arises. This paper utilises the work of Deleuze, Freud, Jung, Heidegger, Hegel and Nietzsche to provide a conceptual framework as to how mental disturbances can arise if unconscious desires cannot be satisfied due to the experience of a resistance from a conflicting or opposing desire. This paper argues that the phenomenal experience of a conflict of desires can be unconcealed in moments of un-readiness-to-hand and from the awareness of the psychophysiological experience of stress or angst. The work that is presented, results in the conclusion that it is fundamentally necessary to embrace Nietzsche’s idea of the ‘will to power’ to overcome these difficulties and to achieve personal individuation and authentic wellbeing. This advice is in contrast to an inauthentic choice of depending on the use of Freudian defence mechanisms to conceal a conflict of desires from consciousness. A detailed theoretical example of the process involved in the resolution of a conflict of desires through self-transcendence is specifically informed by the ideas of Nietzsche and Jung.