Le neuroscienze e la libertà del volere

In the last 30 years, neurosciences, with their mechanistic approach, have dealt with the study of freedom of the will, a field that is considered typical of philosophy or psychology. The studies in neurosciences have been paradoxically appreciated more by philosophers and psychologists than by the scientists themselves, who have straightened the methodological limits. From the considerations of those limits, coming precisely from the neurosciences themselves, rises an interpretation of the freedom of the will that throws a bridge towards positions that are considered typical of philosophical and psychological theories

Oppioidi, MDMA, marijuana e l’immunosoppressione : quale rilevanza clinica?

Obiettivi: Lo scopo di questa breve rassegna \ue8 di riassumere i dati disponibili in letteratura sulle interazioni tra alcune sostanze d\u2019abuso, quali le amfetamine e i loro derivati, la marijuana e gli oppioidi, e la funzione immune. L\u2019 importanza di questi aspetti nella medicina dell\u2019addiction non \ue8 ancora chiara. Metodi: Sono state prese in considerazioni le pubblicazioni pi\uf9 significative presenti in Medline, identificate con opportune parole chiave e scelte secondo l\u2019esperienza degli autori sull\u2019argomento. Risultati: Gli effetti sul sistema immune possono essere indiretti, attraverso l\u2019interazioni dei farmaci con recettori o trasportatori presenti nel sistema nervoso centrale o attraverso l\u2019attivazione di recettori espressi dalle cellule immuni. In particolare per la marijuana e gli oppioidi sono stati chiaramente identificati i recettori specifici su tutte le popolazioni di cellule immuni. Un aspetto comune della immunomodulazione di tutte le sostanze d\u2019abuso sembra essere quello di perturbare l\u2019equilibrio omeostatico tra i linfociti Thelper1, pro infiammatori, in favore dei Thelper 2, di tipo antinfiammatori. Esiste quindi oggi un\u2019ampia letteratura che dimostra come le sostanze d\u2019abuso alterino la funzione immune nell\u2019animale da esperimento e in vitro anche in cellule umane. Nell\u2019animale da esperimento inoltre \ue8 sempre pi\uf9 chiara l\u2019esistenza di una correlazione tra l\u2019effetto immunosoppressivo e l\u2019incidenza di infezioni. L\u2019elevata incidenza di patologie infettive nei soggetti che abusano di sostanze \ue8 ben nota, ma molto pochi sono ancora gli studi nell\u2019uomo che cercano di correlare gli effetti immunosoppressivi con la maggior suscettibilit\ue0 alle infezioni. Conclusione: L\u2019effetto immunosoppressivo dei farmaci d \u2018abuso \ue8 stato ben documentato. Nell\u2019uomo per\uf2 non \ue8 possibile al momento dimostrare l\u2019esistenza di una relazione di causa effetto tra questi effetti ed un aumentato rischio di infezioni. Ulteriori studi saranno necessari per meglio comprendere questo aspetto

The effects of tramadol and morphine on immune responses and pain after surgery in cancer patients

There has been growing interest in determining the possible immune consequences of opioid administration for the management of postoperative pain. We studied the effects of morphine and tramadol on pain and immune function during the postoperative period in 30 patients undergoing abdominal surgery for uterine carcinoma. Phytohemoagglutinin-induced T lymphocyte proliferation and natural killer cell activity were evaluated immediately before and after surgery, and 2 h after the acute administration of either 10 mg of morphine IM or 100 mg tramadol IM for pain. In all patients, phytohemagglutinin-induced lymphoproliferation was significantly depressed by surgical stress. However, in the morphine-treated group, proliferative values remained lower than basal levels for 2 h after treatment, whereas in tramadol-administered patients proliferative values returned to basal levels. Natural killer cell activity was not significantly affected by surgery nor by morphine administration, whereas tramadol significantly enhanced the activity of natural killer cells. Both drugs produced a comparable reduction in postoperative pain. We conclude that, as previously observed in the experimental animal, tramadol and morphine, when administered in analgesic doses, induce different immune effects

Pain stress and headache

The association between pain and stress is an old one, but still it is not really clear who comes first. Pain induces stress, and stress induces pain. Pain is part of our homeostatic system and in this way is an emotion, i.e., it tells us that something is out-of-order (control), and emotion drives our behavior and one behavior is stress response. Stress comes from ourselves: the imagination we have or would like to have of us, from the image others give of us, from the goals we assume it is necessary to reach for our well-being or the goals others want us to fulfill. Stress comes from our social condition and the condition we would like, stress comes from dangerous situations we cannot control. Headache easily fits in the picture

opioid peptides modulate luteinizing hormone secretion during sexual maturation

Subcutaneous injections of naloxone, an opiate antagonist, lead to an increase in serum luteinizing hormone concentrations in female but not in male rats before they reach puberty. In addition, estradiol benzoate specifically blocks the luteinizing hormone response to naloxone in prepubertal female rats, suggesting that the opioid peptides have a physiological role in the endocrine events leading to sexual maturation

Nociceptive induced activation of exploratory behaviour: a role for ß-endorphin.

Examined the role of β-endorphin in the regulation of open-field behavior in 19 male rabbits during the formalin test. Sham-injected Ss showed no pain reactions. Formalin-injected Ss displayed short-lived reactions that appeared immediately after injection, gradually decreased during Trial 2 (1 wk after Trial 1 immediately after β-endorphin treatment), and never recurred in Trial 3 (10 min after treatment). Formalin increased locomotor activity and rearing, but this effect did not occur in anti-β-endorphin-treated Ss. Results suggest that moderate, short-lasting pain induces the release of β-endorphin, which in turn activates locomotor activity and rearing. The β-endorphin system seems to be crucial in facilitating behavioral coping mechanisms and in improving response patter